Endangered and Threatened Wildlife and Plants; Listing 23 Species on Oahu as Endangered and Designating Critical Habitat for 124 Species

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2010-0043; MO 92210-0-0009]

RIN 1018-AV49

Endangered and Threatened Wildlife and Plants; Listing 23 Species on Oahu as Endangered and Designating Critical Habitat for 124 Species

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), propose to list 23 species on the island of Oahu in the Hawaiian Islands as endangered under the Endangered Species Act of 1973, as amended (Act). We also propose to designate critical habitat for these 23 species, to designate critical habitat for 2 plant species that are already listed as endangered, and revise critical habitat for 99 plant species that are already listed as endangered or threatened. The proposed critical habitat designation totals 43,491 acres (ac) (17,603 hectares (ha)), and includes occupied and unoccupied habitat. Approximately 93percent of the area being proposed as critical habitat is already designated as critical habitat for the 99 plant species or other species. In this proposed rule we are also proposing a taxonomic revision of the scientific names of nine plant species.

DATES:

We will consider comments received on or postmarked on or before October 3, 2011. Please note that if you are using the Federal eRulemaking Portal (see

ADDRESSES

section below), the deadline for submitting an electronic comment is Eastern Time on this date. We must receive requests for public hearings, in writing, at the address shown in the

FOR FURTHER INFORMATION CONTACT

section by September 16, 2011.

ADDRESSES:

You may submit comments by one of the following methods:

• Federal eRulemaking Portal:

http://www.regulations.gov.

In the box that reads “Enter Keyword or ID,” enter the docket number for this proposed rule, which is FWS-R1-ES-2010-0043. Check the box that reads “Open for Comments/Submission,” and click the Search Button. You should then see an icon that reads “Submit a Comment.” Please ensure that you have found the correct rulemaking before submitting your comment.

• U.S. mail or hand-delivery: Public Comments Processing, Attn: FWS-R1-ES-2010-0043; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042; Arlington, VA 22203.

We will post all comments on

http://www.regulations.gov.

This generally means that we will post any personal information you provide us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT:

Loyal Mehrhoff, Field Supervisor, Pacific Islands Fish and Wildlife Office, 300 Ala Moana Boulevard, Box 50088, Honolulu, HI 96850; by telephone at 808-792-9400; or by facsimile at 808-792-9581. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

We intend that any final action resulting from this proposal will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we solicit comments or suggestions on this proposed rule from other concerned governmental agencies, the scientific community, industry, or other interested parties concerning this proposed rule. We particularly seek comments concerning:

(1) Biological, commercial trade, or other relevant data concerning any threats (or lack thereof) to the 23 species proposed for listing, and regulations that may be addressing those threats.

(2) Additional information concerning the range, distribution, and population size of each of the 23 species proposed for listing, including the locations of any additional populations of these species.

(3) Any information on the biological or ecological requirements of the 23 species proposed for listing.

(4) Current or planned activities in the areas occupied by both the 23 species proposed for listing and the additional 101 plant species proposed for critical habitat designation or revision, and possible impacts of these activities on this species.

(5) The reasons why we should or should not designate habitat for all species in this proposal as “critical habitat” under section 4 of the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531

et seq.

), including whether there are threats to these species from human activity, the degree of which can be expected to increase due to the designation, and whether the benefit of designation would outweigh threats to these species caused by the designation, such that the designation of critical habitat is prudent.

(6) Whether a revision of critical habitat is warranted for the 99 plant species already listed as endangered or threatened under the Act.

(7) Specific information on:

• The amount and distribution of critical habitat for the species included in this proposed rule;

• What areas currently occupied, and that contain the necessary physical or biological features essential for the conservation of the species, we should include in the designation and why;

• Whether special management considerations or protections may be required for the physical or biological features essential to the conservation of the species in this proposed rule; and

• What areas not currently occupied are essential to the conservation of the species and why.

(8) Land use designations and current or planned activities in the areas occupied by the species, and the possible impacts of proposed or revised critical habitat on these designations or activities.

(9) Any foreseeable economic, national security, or other relevant impacts of designating any area as critical habitat. We are particularly interested in any impacts on small entities, and the benefits of including or excluding areas that exhibit these impacts.

(10) Whether the benefits of excluding any particular area from critical habitat outweigh the benefits of including that area as critical habitat under section 4(b)(2) of the Act, after considering the potential impacts and benefits of the proposed critical habitat designation. Under section 4(b)(2), we may exclude an area from critical habitat if we determine that the benefits of such exclusion outweigh the benefits of including that particular area as critical habitat, unless failure to designate that specific area as critical habitat will result in the extinction of the species. We request specific information on:

• The benefits of including specific areas in the final designation and supporting rationale;

• The benefits of excluding specific areas from the final designation and supporting rationale; and

• Whether any specific exclusions may result in the extinction of the species and why.

(11) Whether our exemptions under section 4(a)(3)(B)(i) of the Act of the lands on Department of Defense (DOD) land at Dillingham Military Reservation,

Kahuku Training Area, Kawailoa Training Area, Makua Military Reservation, Schofield Barracks East Range, and Schofield Barracks Military Reservation, are or are not appropriate and why.

(12) Information on the projected and reasonably likely impact of climate change on the species included in this proposed rule, and any special management needs or protections that may be needed in the critical habitat areas we are proposing.

(13) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

(14) Specific information on ways to improve the clarity of this rule as it pertains to completion of consultations under section 7 of the Act.

(15) Comments on our proposal to revise the taxonomic classification for the nine plant species identified in this proposed rule.

You may submit your comments and materials concerning this proposed rule by one of the methods listed in the

ADDRESSES

section. We request that you send comments only by the methods described in the

ADDRESSES

section.

We will post your entire comment—including your personal identifying information—on

http://www.regulations.gov.

If you provide personal identifying information in addition to the required items specified in the previous paragraph, such as your street address, phone number, or e-mail address, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection at

http://www.regulations.gov,

or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Pacific Islands Fish and Wildlife Office (see

FOR FURTHER INFORMATION CONTACT

).

You may obtain copies of the proposed rule by mail from the Pacific Islands Fish and Wildlife Office (see

FOR FURTHER INFORMATION CONTACT

) or by visiting the Federal eRulemaking Portal at

http://www.regulations.gov.

Background

It is our intent to discuss below only those topics directly relevant to the listing of and designation of critical habitat for the species in this proposed rule.

Previous Federal Action

Nineteen of the 23 species proposed for listing are candidate species (75 FR 69222; November 10, 2010). Candidate species are those taxa for which the Service has sufficient information on their biological status and threats to propose them for listing under the Act, but for which the development of a listing regulation has been precluded to date by other higher priority listing activities. The current candidate species addressed in this proposed listing rule include the plants

Bidens amplectens, Cyanea calycina, C. lanceolata, Cyrtandra kaulantha, C. sessilis, Doryopteris takeuchii, Korthalsella degeneri, Melicope christophersenii, M. hiiakae, M. makahae, Platydesma cornuta

var.

cornuta, P. cornuta var. decurrens, Pleomele forbesii, Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa,

and

Zanthoxylum oahuense;

and the blackline Hawaiian damselfly (

Megalagrion nigrohamatum nigrolineatum

), the crimson Hawaiian damselfly (

M. leptodemas

), and the oceanic Hawaiian damselfly (

M. oceanicum

). The candidate status of all of these species was most recently assessed and reaffirmed in the November 10, 2010, Notice of Review of Native Species that are Candidates for Listing as Threatened or Endangered (CNOR) (75 FR 69222).

On May 4, 2004, the Center for Biological Diversity petitioned the Secretary of the Interior to list 225 species of plants and animals, including the 19 candidate species listed above, as endangered or threatened under the provisions of the Act. Since then, we have published our annual findings on the May 4, 2004, petition (including our findings on the 19 candidate species listed above) in the CNORs dated May 11, 2005 (70 FR 24870), September 12, 2006 (71 FR 53756), December 6, 2007 (72 FR 69034), December 10, 2008 (73 FR 75176), November 9, 2009 (74 FR 57803), and November 10, 2010 (75 FR 69222).

In addition to the 19 candidate species, we are proposing to list four species of plants endemic to Oahu, which include

Cyanea purpurellifolia, Cyrtandra gracilis, C. waiolani,

and

Tetraplasandra lydgatei.

These four Oahu plant species, as well as approximately 180 others on the Hawaiian Islands, have been identified as the “rarest of the rare” Hawaiian plant species in need of immediate conservation, under the multi-agency (Federal, State, and private) Plant Extinction Prevention (PEP) Program. The goal of this program is to prevent the extinction of plant species that currently have fewer than 50 individuals remaining in the wild on the islands of Kauai, Oahu, Maui, Molokai, Lanai, and Hawaii (Hawaii Division of Forestry and Wildlife (DOFAW) 2007; Service 2007). We believe these four endemic Oahu plant species warrant listing under the Act for the reasons discussed in the Summary of Factors Affecting the 23 Species Proposed for Listing section (below). Because these 4 plant species occur within 3 of the 7 ecosystems identified in this proposed rule, and share common threats with the other 19 species proposed for listing under the Act, we have included them in this proposed rule to provide them with protection under the Act in an expeditious manner.

On June 17, 2003, we published a final rule designating approximately 55,040 ac (22,274 ha) as critical habitat for 99 plant species on Oahu (68 FR 35950; June 17, 2003). If made final, this rule would supersede that designation. In addition, we are proposing critical habitat for two endangered plant species for which critical habitat has not been previously proposed or designated. When we listed the plant

Chamaesyce skottsbergii

var.

skottsbergii

in 1982 (47 FR 36846), we found that the designation of critical habitat was not determinable, since we were unable to identify the biological needs of this species (see

Proposed Taxonomic Name Changes

below for additional information). When we listed the plant

Achyranthes splendens

var.

rotundata

as endangered in 1986 (58 FR 10518), we found that designation of critical habitat was not prudent because this plant was threatened by taking for lei-making, and the publication of plant locations could make this plant more vulnerable to collection by individuals. We have reviewed the best available information on both species, and have determined the designation of critical habitat is now prudent (see

Prudency Determination

below for additional information).

An Ecosystem-Based Approach to Listing 23 Species on Oahu

On the island of Oahu, as on most of the Hawaiian Islands, native species that occur in the same habitat types (ecosystems) depend on many of the same biological features and on the successful functioning of that ecosystem to survive. We have therefore organized the species addressed in this proposed rule by common ecosystems. Although the listing determination for each species is analyzed separately, we have

organized the specific analysis for each species within the context of the broader ecosystem in which it occurs, to avoid redundancy. In addition, native species that share ecosystems often face a suite of common factors that may threaten them, and ameliorating or eliminating these threats requires similar management actions. Effective management of these threats often requires implementation of conservation actions at the ecosystem scale, to enhance or restore critical ecological processes and provide for long-term viability of those species in their native environment. Thus, by taking this approach, we hope not only to organize this proposed rule efficiently, but also to more effectively focus conservation management efforts on the common threats that occur across these ecosystems, restore ecosystem functionality for the recovery of each species, and provide conservation benefits for associated native species, thereby potentially precluding the need to list other species under the Act that occur in these shared ecosystems.

We propose to list

Bidens amplectens, Cyanea calycina, Cyanea lanceolata, Cyanea purpurellifolia, Cyrtandra gracilis, Cyrtandra kaulantha, Cyrtandra sessilis, Cyrtandra waiolani, Doryopteris takeuchii, Korthalsella degeneri, Melicope christophersenii, Melicope hiiakae, Melicope makahae, Platydesma cornuta

var.

cornuta, Platydesma cornuta

var.

decurrens, Pleomele forbesii, Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa, Tetraplasandra lydgatei,

and

Zanthoxylum oahuense;

and the blackline, crimson, and oceanic Hawaiian damselflies, endemic to the island of Oahu, as endangered species. These 23 species (20 plants and 3 damselflies) are found in 7 ecosystem types: coastal, lowland dry, lowland mesic, lowland wet, montane wet, dry cliff, and wet cliff (Table 1).

Table 1—The 23 Species and the Ecosystems Upon Which They Depend

Ecosystem

Species

Coastal

Plants:

Bidens amplectens.

Lowland Dry

Plants:

Bidens amplectens, Doryopteris takeuchii, Pleomele forbesii.

Lowland Mesic

Plants:

Cyanea calycina, Cyanea lanceolata, Cyrtandra waiolani, Melicope makahae, Platydesma cornuta

var.

decurrens, Pleomele forbesii, Pteralyxia macrocarpa, Tetraplasandra lydgatei.

Animals: oceanic Hawaiian damselfly.

Lowland Wet

Plants:

Cyanea calycina, Cyanea lanceolata, Cyanea purpurellifolia, Cyrtandra gracilis, Cyrtandra kaulantha, Cyrtandra sessilis, Cyrtandra waiolani, Melicope hiiakae, Melicope makahae, Platydesma cornuta

var.

cornuta, Pleomele forbesii, Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa, Zanthoxylum oahuense.

Animals: crimson Hawaiian damselfly, blackline Hawaiian damselfly, oceanic Hawaiian damselfly.

Montane Wet

Plants:

Cyanea calycina, Melicope christophersenii.

Dry Cliff

Plants:

Korthalsella degeneri, Melicope makahae, Platydesma cornuta

var.

decurrens, Pleomele forbesii, Pteralyxia macrocarpa.

Wet Cliff

Plants:

Cyanea calycina, Cyanea purpurellifolia, Cyrtandra kaulantha, Cyrtandra sessilis, Melicope christophersenii, Psychotria hexandra ssp. oahuensis, Pterlyxia macrocarpa.

Animals: crimson Hawaiian damselfly, oceanic Hawaiian damselfly.

Most of these species are found in multiple ecosystems. For each species, we identified and evaluated those factors that threaten the species and that may be common to all of the species at the ecosystem level. For example, the degradation of habitat by nonnative plants is considered a threat to each species within each ecosystem. As a result, this threat factor is considered to be a multiple ecosystem threat, as each individual species within each ecosystem faces a threat that is essentially identical in terms of the nature of the impact, its severity, its imminence, and its scope. We further identified and evaluated any threat factors that may be unique to certain species, that is, threat factors that do not apply to all species under consideration within the same ecosystem. For example, the threat of predation by nonnative fish is unique to the three damselflies in this proposed rule; it is not applicable to any of the other species proposed for listing. We have identified such threat factors, which apply only to certain species within the ecosystems addressed here, as species-specific threats.

An Ecosystem-Based Approach to Determining Physical or Biological Features of Critical Habitat

Under the Act, we are required to designate critical habitat to the maximum extent prudent and determinable concurrently with the publication of a final determination that a species is endangered or threatened. In this proposed rule, we are proposing to designate critical habitat for the 23 Oahu species for which we are also proposing endangered status. We are also proposing to designate critical habitat for two Oahu plants that are already listed as endangered species but for which critical habitat has not been designated. In addition, we are proposing to revise critical habitat for 99 Oahu plants already listed as endangered or threatened species. When critical habitat was designated for these 99 Oahu plant species in 2003 (68 FR 35950; June 17, 2003), it was based primarily on the specific localities where the species were known to occur. We are proposing to revise critical habitat for these species because since then, we have learned that many native Hawaiian plants and animals currently occupy only areas of marginal habitat because the threats are reduced in these areas, and can thrive when reintroduced into historical habitats when threats are effectively managed. For this reason, we believe it is important to designate unoccupied habitat where it is essential for the recovery of the species. Based on new information on plant occurrences and a better understanding of the species' biological requirements, the physical or biological features have been more precisely identified, and now include elevation, precipitation, substrate, canopy, subcanopy, and understory characteristics. We believe the added precision will be helpful in identifying the special management considerations or protections needed in specific occupied areas to recover the species. In addition, because the 2003 designation focused on discrete areas occupied by the species at the time of listing, the result was an overlapping and confusing patchwork of critical habitat areas for the 99 plant species that was difficult for the public to interpret. Although this proposed revision of critical habitat is solely based on occupied areas with physical or biological features essential to the

species' conservation, and unoccupied areas that are essential to the species' conservation, we believe the end result will provide for greater public understanding of the conservation and recovery needs of each of the species in the specific areas addressed in this proposed rule.

In this proposed rule, we propose critical habitat for 124 species in 66 multiple-species critical habitat units. Although critical habitat is identified for each species individually, we have found that the conservation of each depends, at least in part, on the successful functioning of the physical or biological features of the commonly shared ecosystem. Each critical habitat unit identified in this proposed rule contains the physical or biological features essential to the conservation of those individual species that occupy that particular unit, or contains areas essential to the conservation of those species that do not presently occupy that particular unit but depend on that ecosystem type for recovery purposes. Where the unit is not occupied by a particular species, we believe it is still essential for the conservation of that species. The designation of unoccupied habitat allows for the expansion of its range and reintroduction of individuals into areas where it occurred historically, and provides area for recovery in the case of a stochastic event at one or more locations where the species occurs.

Each of the areas proposed for designation represents critical habitat for multiple species, based upon their shared habitat requirements, and takes into account any species-specific conservation needs as appropriate. For example, the presence of a perennial stream is essential for the conservation of the blackline Hawaiian damselfly, but is not a requirement shared by all species within the same ecosystem; however, a functioning ecosystem is also essential to the damselfly because the ecosystem provides other physical or biological features that support the damselfly's specific life-history requirements.

The Island of Oahu

The island of Oahu is the third oldest and third largest of the eight main Hawaiian Islands, located southeast of Kauai and northwest of Molokai and Lanai (Foote

et al.

1972, p. 19; Department of Geography, University of Hawaii at Hilo (UHH) 1998, p. 7). It was formed from two shield volcanoes that ceased erupting about 1 to 2 million years ago, and is about 600 square (sq) miles (mi) (1,557 sq kilometers (km)) in area (Macdonald and Abbot 1970, p. 265; Foote

et al.

1972, p. 19; Department of Geography, UHH 1998, p. 7). Two mountain ranges resulted from these eruptions, the western Waianae range and eastern Koolau range. Oahu is characterized by the fact that the two mountain ranges are aligned perpendicular to the prevailing trade winds, so that distinctive leeward and windward climates result, with the Waianae range in the rain shadow of the Koolau range (Department of Geography, UHH 1998, p. 7; Wagner

et al.

1999, p. 39). The maximum elevation on Oahu is 4,025 feet (ft) (1,225 meters (m)) at the summit of Mount Kaala in the Waianae Mountains, and this higher elevation area is not affected by the rain shadow (Blumenstock and Price 1972, p. 156; Wagner

et al.

1999, pp. 39-41). The maximum elevation is relatively low compared to the higher Hawaiian Islands. Consequently, Oahu does not have dry alpine areas, as the mountains do not reach the height of the temperature inversion layer (Wagner

et al.

1999, pp. 38, 40). Rainfall ranges from less than 20 inches (in) (500 millimeters (mm)) to more than 250 in (6,350 mm) per year (Department of Geography, UHH 1998, p. 7). Temperatures in the Hawaiian Islands differ by an average of 41 degrees Fahrenheit (°F) (22 degrees Celsius (°C)) throughout the year. Since temperature decreases with increasing elevation, microclimates range from tropical to sub-arctic across the island chain (Wagner

et al.

1999, pp. 37-38), although the sub-arctic zone does not occur on Oahu.

The current soil classification system for the Hawaiian Islands distinguishes soil types based on their measurable physical and chemical properties and environmental factors that influenced their formation. Widely ranging geological ages of rocks, different rates of weathering, and microclimates create these highly variable soils (Sherman 1972, pp. 205-207). Most soils are volcanic in origin; a few formed from organic material and sand (Foote

et al.

1972, p. 1). On Oahu, sizable areas of highly weathered, red-colored oxisols (nutrient poor soils, red or yellowish) occur on the Schofield Plateau; in contrast, the Koolau and Waianae mountain ranges have large areas of rocky, unweathered entisols (soils with few or no horizontal layers) due to erosion (Gavenda

et al.

1998, p. 92).

Because of its age and relative isolation, species diversity and endemism are high in the Hawaiian archipelago (Gagne and Cuddihy 1999, p. 45). However, the flora and fauna of Oahu have undergone extreme alterations because of past and present land use and other activities. Land with rich soils was altered by the early Hawaiians and, more recently, converted to agricultural use (Gagne and Cuddihy 1999, p. 45) or pasture. Intentional and inadvertent introduction of alien plant and animal species has contributed to the reduction in range of native species on the island (throughout this proposal, the terms “alien,” “feral,” “nonnative,” and “introduced” all refer to species that are not naturally native to the Hawaiian Islands.) Most of the taxa included in this proposed rule persist on steep slopes, precipitous cliffs, valley headwalls, and other regions where unsuitable topography has prevented urbanization and agricultural development, or where inaccessibility has limited encroachment by nonnative plant and animal species.

Oahu Ecosystems

The seven Oahu ecosystems that support the species addressed in this proposed rule are described in the following sections.

Coastal

The coastal ecosystem is found on all of the main Hawaiian Islands, with the highest species diversity found in the least populated coastal areas of Hawaii, Maui, Molokai, Kahoolawe, Oahu, and Kauai, and their associated islets. On Oahu, the coastal ecosystem includes mixed herblands, shrublands, and grasslands, from sea level to approximately 980 ft (300 m) in elevation, generally within a narrow zone above the influence of waves to within 330 ft (100 m) inland, sometimes extending farther inland if strong prevailing onshore winds drive sea spray and sand dunes into the lowland zone (The Nature Conservancy (TNC) 2006a). The coastal vegetation zone is typically dry, with annual rainfall of less than 20 in (50 cm); however, windward rainfall may be high enough (up to 40 in (100 cm)) to support mesic-associated and sometimes wet-associated vegetation (Gagne and Cuddihy 1999, pp. 54-66). Biological diversity is low to moderate in this ecosystem, but may include some specialized plants and animals such as nesting seabirds and the rare native plant

Sesbania tomentosa

(ohai) (TNC 2006a). The plant

Bidens amplectens,

which is proposed for listing as endangered in this proposed rule, is reported from this ecosystem on Oahu (Hawaii Biodiversity and Mapping Program (HBMP) 2008; TNC 2007).

Lowland Dry

The lowland dry ecosystem includes shrublands and forests generally below

3,300 ft (1,000 m) elevation that receive less than 50 in (130 centimeters (cm)) annual rainfall, or are in otherwise prevailingly dry substrate conditions. Areas consisting of predominantly native species in the lowland dry ecosystem are now rare; however, this ecosystem is found on the islands of Hawaii, Molokai, Lanai, Kahoolawe, Oahu, and Kauai, and is best represented on the leeward sides of the islands (Gagne and Cuddihy 1999, p. 67). On Oahu, this ecosystem is typically found on the leeward side of the Waianae Mountains, and the leeward southern coast, including Diamond Head Crater (Gagne and Cuddihy 1999, p. 67; TNC 2006b). Biological diversity is low to moderate in this ecosystem, and includes specialized animals and plants such as the Hawaiian owl or pueo (

Asio flammeus sandwichensis

) and

Santalum ellipticum

(iliahialoe) (Wagner

et al.

1999, pp. 1,220-1,221; TNC 2006b). The plants

Bidens amplectens, Doryopteris takeuchii,

and

Pleomele forbesii,

which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem on Oahu (HBMP 2008; TNC 2007).

Lowland Mesic

The lowland mesic ecosystem includes a variety of grasslands, shrublands, and forests, generally below 3,300 ft (1,000 m) elevation, that receive between 50 and 75 in (130 and 190 cm) annual rainfall, or are in otherwise mesic substrate conditions (TNC 2006c). In the Hawaiian Islands, this ecosystem is found on Hawaii, Maui, Molokai, Lanai, and Kauai, on both windward and leeward sides of the islands. On Oahu, this ecosystem is typically found on the leeward slopes of both the Waianae and Koolau Mountains (Gagne and Cuddihy 1999, p. 75; TNC 2006c). Biological diversity is high in this system (TNC 2006c). The plants

Cyanea calycina, C. lanceolata,

Cyrtandra waiolani, Melicope makahae,

Platydesma cornuta

var.

decurrens, Pleomele forbesii,

Pteralyxia macrocarpa,

and

Tetraplasandra lydgatei,

and the oceanic Hawaiian damselfly, which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem (HBMP 2008; TNC 2007).

Lowland Wet

The lowland wet ecosystem is generally found below 3,300 ft (1,000 m) elevation on the windward sides of the main Hawaiian Islands, except Kahoolawe and Niihau (Gagne and Cuddihy 1999, p. 85; TNC 2006d). These areas include a variety of wet grasslands, shrublands, and forests that receive greater than 75 in (190 cm) annual precipitation, or are in otherwise wet substrate conditions (TNC 2006d). On Oahu, this system is best developed in wet valleys and slopes along the summit of the Koolau Mountains, with a small area located on the windward side of the summit of the Waianae Mountains (TNC 2006d). Biological diversity is high in this system (TNC 2006d). The plants

Cyanea calycina, C. lanceolata,

C. purpurellifolia, Cyrtandra gracilis,

C. kaulantha, C. sessilis,

C. waiolani, Melicope hiiakae,

M. makahae, Platydesma cornuta

var.

cornuta, Pleomele forbesii,

Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa,

and

Zanthoxylum oahuense;

and the blackline, crimson, and oceanic Hawaiian damselflies, which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem (HBMP 2008; TNC 2007).

Montane Wet

The montane wet ecosystem is composed of natural communities (grasslands, shrublands, forests, and bogs) found at elevations generally between 3,300 and 6,600 ft (1,000 and 2,000 m), in areas where annual precipitation is greater than 75 in (190 cm) (TNC 2006e). This system is found on all of the main Hawaiian Islands except Niihau and Kahoolawe (only the islands of Molokai, Maui, and Hawaii have areas above 4,020 ft (1,225 m)) (TNC 2006e). On Oahu, this ecosystem is found only at the summit of the Waianae Mountains (TNC 2007). Biological diversity is moderate to high (TNC 2006e). Due to the restricted distribution of this ecosystem on Oahu, only the plants

Cyanea calycina

and

Melicope christophersenii,

which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem (HBMP 2008; TNC 2007).

Dry Cliff

The dry cliff ecosystem is composed of vegetation communities occupying steep slopes (greater than 65 degrees) in areas that receive less than 75 in (190 cm) of rainfall annually, or are in otherwise dry substrate conditions (TNC 2006f). This ecosystem is found on all of the main Hawaiian Islands except Niihau, and on the island of Oahu is best represented along the leeward slopes of the Waianae Mountains (TNC 2006f). A variety of shrublands occur within this ecosystem (TNC 2006f). Biological diversity is low to moderate (TNC 2006f). The plants

Korthalsella degeneri, Melicope makahae,

Platydesma cornuta

var.

decurrens, Pleomele forbesii,

and

Pteralyxia macrocarpa,

which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem (HBMP 2008; TNC 2007).

Wet Cliff

The wet cliff ecosystem is generally composed of shrublands on near-vertical slopes (greater than 65 degrees) in areas that receive more than 75 in (190 cm) of annual precipitation, or in otherwise wet substrate conditions (TNC 2006g). This system is found on the islands of Hawaii, Maui, Molokai, Lanai, Oahu, and Kauai. On Oahu, this ecosystem is typically found along the entire length of the summit of the Koolau Mountains and at the summit of Mt. Kaala in the Waianae Mountains (TNC 2006g). Biological diversity is low to moderate (TNC 2006g). The plants

Cyanea calycina, C. purpurellifolia,

Cyrtandra kaulantha, C. sessilis,

Melicope christophersenii, Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa;

and the crimson and oceanic Hawaiian damselflies, which are proposed for listing as endangered in this proposed rule, are reported in this ecosystem (HBMP 2008; TNC 2007).

Species Description of the 23 Species Proposed for Listing

Below is a brief description of each of the 23 species proposed for listing, presented in alphabetical order by genus. Plants are presented first, followed by animals.

Plants

Bidens amplectens

(kookoolau), a perennial or sometimes annual herb in the sunflower family (Asteraceae), is restricted to windward cliffs and crests along the northern portion of the Waianae Mountains on the island of Oahu, in the coastal and lowland dry ecosystems, at elevations between 300 and 1,400 ft (90 and 430 m) (Ganders and Nagata 1999, p. 271; TNC 2007; HBMP 2008). This species intergrades with

B. torta

and forms hybrid swarms from near Kaena Point along the Waianae summit ridges to the head of Makua Valley (a hybrid swarm occurs where there is no reproductive barrier between distinct populations, or where a barrier has broken down). Pure

B. amplectens

is restricted to the windward cliffs and crests of the Waianae range (Ganders and Nagata 1999, p. 271).

Bidens amplectens

was historically known from five locations spanning 7 mi (11 km) in the northern Waianae Mountains including Makaleha Valley, Uluhulu Gulch, Puu Pueo to Alau Gulch, Manini Gulch to Alau Gulch, and Nihoa Gulch (HBMP 2008).

At last observation, it totaled fewer than 1,000 individuals in four locations separated by less than 4 mi (6 km): Kealia Trail on the east side of Haili Gulch; Kapuna-Kamimi Ridge on the road to the Pahole Natural Area Reserve (NAR); Kealia east of Kawaiu Gulch; and from Kuaokala to Keawaula Ridge (J. Lau, in litt. 2001; HBMP 2008).

Cyanea calycina

(haha), an unbranched shrub in the bellflower family (Campanulaceae), is found in both the Waianae and Koolau Mountains of Oahu in the lowland mesic, lowland wet, montane wet, and wet cliff ecosystems (Lammers 1999, p. 483; Wagner and Herbst 2003, p. 17; TNC 2007; HBMP 2008). In the Waianae Mountains,

C. calycina

occurs in

Acacia-Metrosideros-Dicranopteris

(koa-ohia-uluhe) forests at elevations between 1,800 and 3,920 ft (550 and 1,195 m), and in the Koolau Mountains this species occurs in wet

Metrosideros-Dicranopteris

forest and shrubland at elevations generally between 1,830 and 3,000 ft (558 and 900 m) (HBMP 2008). Historically, in the Waianae Mountains, plants were found from Palikea Gulch to Pualii Gulch (HBMP 2008). Currently,

C. calycina

is found from Pahole in the northern portion of the Waianae Mountains south along the summit to Palawai in 18 occurrences totaling at least 170 individuals (U.S. Army 2006; HBMP 2008). In the Koolau Mountains,

C. calycina

was known historically along the entire length of the range (HBMP 2008). Currently, 22 occurrences totaling between 155 and 169 individuals are known, from the most northern point at Kamananui Gulch along the summit ridges south to Konahuanui (U.S. Army 2006; HBMP 2008). The combined 40 occurrences total 325 to 339 individuals.

Cyanea lanceolata

(haha) is an unbranched shrub in the bellflower family (Campanulaceae) that occurs in the southeastern Koolau Mountains in the lowland mesic and lowland wet ecosystems, at elevations generally between 1,000 and 2,500 ft (300 and 760 m) (Wagner

et al.

1999, p. 483; Wagner and Herbst 2003, p. 17; TNC 2007; HBMP 2008). Historically, this species was wide-ranging along the Koolau Mountains, from the northern Schofield-Waikane area to Wailupe at the southern end of the range, in at least 17 occurrences (HBMP 2008). Currently, there are 7 known occurrences, totaling fewer than 123 individuals, sparsely scattered over a much smaller area of the southern and northern Koolau range. The southern occurrences include Kului-Hawaii Loa, Wailupe, Mauumae, and Waialae Nui, with an unconfirmed report of individuals in Pia Valley (HBMP 2008; J. Lau, in litt. 2008). The northern occurrences include individuals north of Kawaiiki Stream, at Poamoho, and at Peahinaia (U.S. Army 2006).

Cyanea purpurellifolia

(haha) is an unbranched shrub in the bellflower family (Campanulaceae) that occurs in the Koolau Mountains in the lowland wet and wet cliff ecosystems, at elevations generally between 1,860 and 2,160 ft (570 and 660 m) (TNC 2007; HBMP 2008). Historically, this species was known from a few individuals in the vicinity of Kaluanui Valley and north to Maakua-Papali Ridge (Lammers 1999, p. 484; Wagner and Herbst 2003, p. 17; HBMP 2008). Currently,

C. purpurellifolia

occurs in the northern Koolau Mountains from Maakua-Kaipapau to Punaluu-Kaluanui Ridge, in 5 occurrences totaling approximately 18 individuals (Plant Extinction Prevention (PEP) Program 2008, pp. 20-21; HBMP 2008).

Cyrtandra gracilis

(haiwale) (Gesneriaceae, African violet family) is a perennial shrub that is found in

Metrosideros-Dicranopteris

forest in the lowland wet ecosystem at approximately 1,600 ft (490 m) in elevation, on the leeward side of the southern Koolau Mountains (Wagner

et al.

1999, p. 755; National Tropical Botanical Garden (NTBG) Provenance Report 2004; TNC 2007; HBMP 2008; PEP Program 2008, p. 16). Presumed extinct since the 1800s, 10 individuals of

C. gracilis

were discovered by botanists in Pia Valley in 2001 (NTBG Provenance Report 2002). Between 2001 and 2008, only six to eight plants were observed at this location (NTBG Provenance Report 2002; PEP Program 2008, p. 16; A. Bakutis, in litt. 2008). It is apparently extirpated from historical locations in Palolo Valley, Konahuanui Gulch, and Manoa Valley (Wagner

et al.

1999, p. 755; HBMP 2008).

Cyrtandra kaulantha

(haiwale) is a perennial shrub in the African violet family (Gesneriaceae) found in dense shade in moist wooded gulches at elevations generally between 840 and 1,050 ft (255 and 320 m), in the lowland wet and wet cliff ecosystems in the Koolau Mountains (Wagner

et al.

1999, p. 763; TNC 2007; HBMP 2008).

Cyrtandra kaulantha

was historically known from the Waiahole Ditch trail and Kahanaiki Stream. It was considered “locally common,” and a collection was taken from a “large colony” in 1985 (W. Takeuchi, in litt. 1985; Wagner

et al.

1999, p. 763; J. Lau, in litt. 2006). Prior to October 2005, there were 34 wild individuals in 3 occurrences (15, 8, and 11 individuals, respectively) in the subgulches of Waianu Valley (A. Bakutis, in litt. 2005). In 2005, the third occurrence was discovered crushed by a tree, leaving six living individuals (A. Bakutis, in litt. 2005). In March 2006, it was reported that only one individual remained at the second occurrence, and that some individuals in the other two occurrences had fruit (A. Bakutis, in litt. 2006a). In addition, 4 more individuals were discovered at the site of the first occurrence, bringing the total number of wild individuals to 26 (Bakutis 2006a). In May 2006, another tree fall crushed 4 individuals in the third occurrence, leaving 2 remaining; however, a fourth occurrence of 4 individuals was discovered in another subgulch, and 1 new individual was found in the first occurrence, bringing the total number of wild individuals to 27 (A. Bakutis, in litt. 2006a; Bakutis 2006b). All occurrences were visited again in April 2007, with a total of 28 wild individuals observed (PEP Program 2007, p. 17). Outplanting has been conducted in the four subgulches of Waianu Valley, but in areas some distance from the known occurrences. A total of 28 individuals were outplanted between 2005 and 2007. However, due to predation by nonnative slugs, only 12 outplanted individuals remained in 2007 (PEP Program 2007, p. 17).

Cyrtandra kaulantha

is therefore currently found in 5 occurrences totaling 28 wild and 12 outplanted individuals.

Cyrtandra sessilis

(haiwale) (Gesneriaceae, African violet family) is a small shrub that was historically known only from a few collections in wet gulch bottoms and slopes of mesic valleys in the windward Koolau Mountains (Wagner

et al.

1999, p. 778). Typical habitat is

Metrosideros

forests at elevations generally between 1,600 and 2,200 ft (490 and 670 m) in the lowland wet and wet cliff ecosystems (TNC 2007; HBMP 2008; A. Bakutis, in litt. 2008). In 1993, there were about 200 individuals in the only known occurrence near the summit of the Schofield-Waikane Trail (HBMP 2008). In 2003, there were an estimated 50 individuals in 2 occurrences (S. Perlman, in litt. 2003).

Cyrtandra sessilis

is currently known from 2 occurrences, one consisting of 75 individuals along the Waikane-Schofield Trail in Kahana Valley and the second consisting of 5 individuals at Hawaii Loa Ridge near Pia Valley (S. Perlman, in litt. 2003; A. Bakutis, in litt. 2006c; HBMP 2008; A. Bakutis, in litt. 2008).

Cyrtandra waiolani

(haiwale), a small shrub in the African violet family (Gesneriaceae), is found in rich, partly sunny gulches; shady, moist banks above creeks; and wet gulch bottoms in

mesic valleys in the lowland mesic and lowland wet ecosystems (Wagner

et al.

1999, p. 781; HBMP 2008).

Cyrtandra waiolani

was historically known from at least seven locations: five in the southern Koolau Mountains and two in the northern Koolau Mountains, at elevations generally between 800 and 3,000 ft (240 and 900 m) (HBMP 2008). Plants have not been since observed in these areas (HBMP 2008). Individuals likely representing

C. waiolani,

based on vegetative characteristics, were seen in 1994 along the ridge between Kaipapau and Maakua, and in 2005 in Kahana, but these plants are no longer alive (J. Lau, in litt. 2009). In 2005, individuals thought to be

C. waiolani

were found on the Kualono Ridge near Kaaawa; however, these plants were not flowering or fruiting at that time. Cuttings were taken for propagation and positive identification when flowering and fruiting occur (Hawaii Department of Land and Natural Resources (HDLNR) 2005; U.S. Army 2006; A. Bakutis, in litt. 2008; S. Ching, PEP, in litt. 2009; J. Lau, in litt. 2009). Many areas within the lowland mesic ecosystem in Kaaawa in the Koolau Mountains have not been surveyed for this species, including three of the historically known locations from Anahulu to Lanihuli. The Koolau mountain range is over 35 mi (58 km) in length. Historic surveys that we have records of from the 1800s did not cover the entire mountain range, but collections were made at seven widely distributed locations along the 35-mi (58-km) range. In the 1800s, forests in the Koolau Mountains were more intact at the summits; therefore, we believe that if seven collections were made, there were many more individuals in the wild. The plants were only known from a ridge between Kaipapau and Maakua in 1994, and from Kahana in 2005, but those plants are no longer present, which represents a population decline from seven (and more than seven historically) to zero. Botanists suggest that the species is likely still extant in these areas and may be found with more intensive surveying (Bakutis 2008a; J. Lau, in litt. 2009).

Doryopteris takeuchii

(no common name (NCN)) is a fern in the Pteridaceae family (Palmer 2003, p. 133). It occurs in dry shrubland on the slopes of Diamond Head Crater, a volcanic tuff cone on the southern coast of Oahu, at elevations generally between 140 and 300 ft (43 and 91 m) (NTBG 2007, p.1). This area consists of pockets of native and nonnative species in the lowland dry ecosystem (TNC 2007). Little is known of the historical distribution of

D. takeuchii.

Currently, there are 101 to 124 clumps on the Kuilei cliffs and the southwest-facing gulches above Munro Trail on the outer slopes of the crater (NTBG 2007, p. 1).

Korthalsella degeneri

(hulumoa), a subshrub (a perennial with stems that are woody at the base) in the mistletoe family (Viscaceae), is parasitic on the native trees

Sapindus oahuensis

(kaulu) and

Nestegis sandwicensis

(olopua) (Wagner

et al.

1999, p. 1,339). This species occurs in diverse forest in the dry cliff ecosystem at elevations generally between 1,100 and 1,500 ft (335 and 457 m) in the Waianae Mountains (U.S. Army 2006; TNC 2007; HBMP 2008). In 1938,

K. degeneri

was recorded from Makua Valley but little else is known of its historical range (HBMP 2008). Currently, this species is known only from one widespread occurrence in Makua Valley, estimated to be between 900 and 1,000 individuals (J. Lau, in litt. 2000), and one occurrence of an unknown number of individuals in Makaha on the north-facing slopes of the southern side of the valley (U.S. Army 2006).

Melicope christophersenii

(alani), a shrub or tree in the rue family (Rutaceae), occurs in wet forest and shrubland in the montane wet and wet cliff ecosystems at elevations generally between 2,400 and 4,010 ft (732 and 1,222 m) in the Waianae Mountains (Stone

et al.

1999, pp. 1,184-1,185; U.S. Army 2006; TNC 2007; HBMP 2008). Historically,

M. christophersenii

was known from the Mt. Kaala area of the Waianae Mountains, and as far south as Puu Kaua (HBMP 2008). Currently, there are 3 occurrences totaling approximately 250 individuals in the Waianae summit area, with the southernmost occurrence at Puu Hapapa (U.S. Army 2006; HBMP 2008).

Melicope hiiakae

(alani) is a small tree in the rue family (Rutaceae) that occurs in wet forest in the lowland wet ecosystem in the Koolau Mountains, generally between elevations of 1,300 and 2,260 ft (396 and 689 m) (U.S. Army 2006; NTBG 2007, p. 3; TNC 2007; HBMP 2008). Historically,

M. hiiakae

was found along the entire length of the Koolau range (HBMP 2008). Currently there are 8 scattered occurrences totaling fewer than 40 individuals from Kawailoa to Waimalu (NTBG 2007, p. 3; HBMP 2008).

Melicope makahae

(alani), a shrubby tree in the rue family (Rutaceae), occurs in mesic and wet forest and shrubland in the lowland mesic, lowland wet, and dry cliff ecosystems in the Waianae Mountains, at elevations generally between 2,200 and 2,900 ft (670 and 884 m) (Stone

et al.

1999, p. 1,194; U.S. Army 2006; TNC 2007; HBMP 2008). Historically,

M. makahae

was found in the central summit area of the Waianae Mountains on the west side of Mt. Kaala in Makaha Valley (Stone 1963, p. 410; TNC 2007). Currently, there are 4 occurrences totaling fewer than 200 individuals north and west of the summit area of the Waianae Mountains (HBMP 2008).

Platydesma cornuta

var.

cornuta

(NCN) is a palmoid (leaves dividing or radiating from one point) shrub in the rue family (Rutaceae) (Stone

et al.

1999, pp. 1,209-1,210). It occurs in wet forest, shrubland, and gulches in the lowland wet ecosystem of the Koolau Mountains, at elevations generally between 1,900 and 2,500 ft (579 and 762 m) (U.S. Army 2006; TNC 2007; HBMP 2008). Historically, this species was found along the entire length of the Koolau range, and at elevations below 800 ft, from Pupukea to Wailupe Valley (HBMP 2008). Currently, 9 occurrences (totaling 32 individuals) are restricted to the summit area of the northern Koolau Mountains, with only 1 occurrence (16 individuals) near the summit of the southern Koolau Mountains (HBMP 2008).

Platydesma cornuta

var.

decurrens

(NCN), a palmoid shrub in the rue family (Rutaceae), occurs in the lowland mesic and dry cliff ecosystems of the Waianae Mountains, at elevations generally between 1,990 and 3,000 ft (607 and 914 m) (Stone

et al.

1999, pp. 1,209-1,210; U.S. Army 2006; TNC 2007; HBMP 2008). Historically this species was wide-ranging in the Waianae Mountains, from the Mokuleia Forest Reserve south to Kaluaa (TNC 2007; HBMP 2008). Currently,

P. cornuta

var.

decurrens

is found in 15 occurrences scattered from Pahole to Palawai Gulch, totaling 259 to 309 individuals (U.S. Army 2006; HBMP 2008).

Pleomele forbesii

(hala pepe) is a tree in the asparagus (Asparagaceae) family (Smithsonian Department of Botany 2008). It occurs in mesic and dry forest and shrubland in the lowland dry, lowland mesic, lowland wet, and dry cliff ecosystems in the Waianae and Koolau Mountains, at elevations generally between 800 and 2,920 ft (244 and 890 m) (Wagner

et al.

1999, p. 1,352; TNC 2007; HBMP 2008). Historically,

P. forbesii

was found in at least 11 areas, totaling an unknown number of individuals, in the Waianae Mountains (HBMP 2008). Currently, there are approximately 19 occurrences totaling 290 to 307 individuals, from the Mokuleia Forest Reserve, west to Keaau and south to Nanakuli, in the Waianae Mountains, and one occurrence of a few

individuals in the Koolau Mountains (J. Lau, in litt. 2008; HBMP 2008).

Psychotria hexandra

ssp.

oahuensis

(kopiko), a tree in the coffee family (Rubiaceae), occurs in wet forest and shrubland in the lowland wet and wet cliff ecosystems of the Koolau Mountains, at elevations generally between 1,080 and 2,000 ft (329 and 610 m) (Wagner

et al.

1999, p. 1,166; TNC 2007; HBMP 2008). Historically known only from the northern Koolau Mountains, this species is currently known from three occurrences in that area: one occurrence of 8 to 9 individuals in Maakua Gulch; 1 individual at Opaeula Gulch; and an estimated fewer than 10 individuals scattered between Kaipapau and Kaluanui, just south of Maakua Gulch (A. Bakutis, in litt. 2005; U.S. Army 2006; PEP Program 2007, p. 25; HBMP 2008). A single individual was outplanted within a fenced area in Makaua Valley (February 2007) and has been observed to be healthy in subsequent monitoring visits (PEP Program 2007, p. 25).

Pteralyxia macrocarpa

(kaulu) is a tree in the dogbane family (Apocynaceae). It occurs in the Waianae and Koolau Mountains, in the lowland mesic, lowland wet, dry cliff, and wet cliff ecosystems, at elevations generally between 1,100 and 2,800 ft (335 and 850 m) (Wagner

et al.

1999, p. 220; U.S. Army 2006; TNC 2007; HBMP 2008). Historically, this species was found along the entire length of the Koolau range and on the summit ridges of the Waianae Mountains (HBMP 2008). Currently,

P. macrocarpa

is found from Kapuhi Gulch to North Palawai Gulch in the Waianae Mountains, in approximately 31 occurrences totaling between 233 and 289 individuals. In the Koolau Mountains, 7 occurrences totaling 47 individuals occur in the most northern portion of this mountain range, while only 11 individuals in 2 occurrences are found in the southernmost portion of the range (U.S. Army 2006; HBMP 2008).

Tetraplasandra lydgatei

(NCN), a tree in the ginseng family (Araliaceae), is found in mesic forest in the lowland mesic ecosystem at elevations generally between 800 and 1,600 ft (240 and 490 m) in the Koolau Mountains (Motley 2005, p. 107; TNC 2007). In 2005, Motley formally recognized

T. lydgatei

as distinct from

T. oahuensis

(Motley 2005; p. 105), and all known occurrences were surveyed at that time (PEP Program 2007, pp. 27-28). Formerly found from Niu Valley to the Halawa Ridge Trail, its distribution is now limited to two wild occurrences: one on the eastern slope of Hawaii Loa Ridge and another on the slopes of Kuliouou Valley. These occurrences total eight individuals (PEP Program 2007, pp. 27-28). In addition, 34 individuals have been outplanted in a fenced enclosure at Kulepeamoa Ridge (PEP Program 2007, p. 28).

Zanthoxylum oahuense

(ae), a small tree in the rue family (Rutaceae), occurs in wet forest in the lowland wet ecosystem at elevations generally between 2,060 and 2,720 ft (628 and 829 m) (Wagner

et al.

1999, p. 1,216; TNC 2007; HBMP 2008). This species was historically known from 17 areas along the entire length of the Koolau Mountains (HBMP 2008). Currently,

Z. oahuense

is restricted to the northern Koolau Mountains from Puu Kainapuaa along the summit to Waimano Stream, in 8 occurrences totaling approximately 29 individuals (U.S Army 2006; HBMP 2008).

Animals

The crimson Hawaiian damselfly is a medium-sized, slender and delicate species, with adults measuring from 1.4 to 1.6 in (36 to 41 mm) in length and having a wingspan of 1.5 to 1.6 in (39 to 42 mm). The species exhibits minimal striping and patterns. Males are primarily red and black in color, with females appearing somewhat paler and with green coloration present on the abdomen laterally (Polhemus and Asquith 1996, p. 65).

The crimson Hawaiian damselfly breeds in the slow reaches of streams and seep-fed pools (Williams 1936, p. 306; Zimmerman 1948a, p. 369; Polhemus 1994a, p. 7; Polhemus 1994b, p. 37). Crimson Hawaiian damselfly naiads, the aquatic life-history stage, frequent open water, resting horizontally, submerged below the surface, or on submerged vegetation (Williams 1936, p. 309). Adults perch on streamside vegetation and patrol along the stream corridor, staying close to breeding pools (Polhemus and Asquith 1996, p. 65).

Between 1991 and 2003, over 150 sites were surveyed on the island of Oahu for native damselflies, and results indicate that one lowland species, the Pacific Hawaiian damselfly, has been extirpated from Oahu, and the orangeblack Hawaiian damselfly has been reduced to a single remnant population (Polhemus 2007, pp. 233-235). The crimson Hawaiian damselfly was known historically from approximately eight areas where it is now extirpated, including the windward side of the Waianae Mountains and scattered locations in the Koolau Mountains (Polhemus 1994a, p. 7; Polhemus 1994b, pp. 37-38; Englund 1999, pp. 228-229, 231; Polhemus 2007, pp. 234, 238). In 2003, this species was not found during surveys of Kahana Stream and may be extirpated from this stream system (D. Polhemus, in litt. 2008). Currently, only five occurrences of the crimson Hawaiian damselfly are known, all from the Koolau Mountains in the lowland wet and wet cliff ecosystems at Waiawa, north Halawa, Punaluu, Moanalua, and Hauula (TNC 2007; D. Polhemus, in litt. 2008; HBMP 2008). All colonies of this damselfly are constrained to portions of streams not occupied by nonnative predatory fish—that is, stream portions above geologic or manmade barriers (e.g., waterfalls, steep gradients, dry stream midreaches, or constructed diversions). No estimates of population size for the crimson Hawaiian damselfly are available.

The blackline Hawaiian damselfly is a moderately-sized and delicate subspecies (Polhemus and Asquith 1996, p. 73). It occurs in and along the slow sections or pools of mid-reach and headwater sections of perennial upland streams and in seep-fed pools along overflow channels bordering such streams. The adults measure from 1.4 to 1.8 in (35 to 45 mm) in length and have a wingspan of 1.7 to 1.9 in (45 to 50 mm). Naiads remain concealed and are found in the water under stones or in mats of algae (Williams 1936, p. 318; Zimmerman 1948, pp. 371-372).

The blackline Hawaiian damselfly was known historically from the Koolau and Waianae Mountains, from sea level to over 2,400 ft (732 m) (Williams 1936, p. 318; Polhemus 1994a, pp. 6-12). Currently, this species is found in the lowland wet ecosystem on the windward and leeward sides of the Koolau Mountains, in the headwaters and upper reaches of 17 streams: Koloa, Kaluanui, Helemano, Poamoho, Kahana, Waikane, Waiahole, Waianu, Waiawa, Kaalaea, Waihee, Kahaluu, north Halawa, Heeia, Kalihi, Moole, and Maunawili (TNC 2007; D. Polhemus, in litt. 2008; R. Wolff, USGS, in litt. 2008; HBMP 2008). Like the crimson Hawaiian damselfly, all colonies of the blackline Hawaiian damselfly are constrained to portions of streams not occupied by nonnative predatory fish—that is, stream portions above geologic or manmade barriers (e.g., waterfalls, steep gradients, dry stream midreaches, or constructed diversions). Currently, the 17 stream colonies are estimated to total 800 to 1,000 individuals, with approximately 50 individuals per stream (D. Polhemus, in litt. 2008).

The oceanic Hawaiian damselfly is a comparatively large and robust species. The adults measure from 1.8 to 1.9 in (47 to 50 mm) in length and have a

wingspan of 2.0 to 2.2 in (51 to 55 mm). Both sexes exhibit prominent patterns including black stripes, but males are bright red in color while females are pale green. Immature individuals of this species are also large with long grasping legs and dagger-like gills (Polhemus and Asquith 1996, p. 77). The oceanic Hawaiian damselfly can be distinguished from other Oahu damselfly species by its large size, black stripes, and fast flight along flowing sections of streams.

Individuals of the immature stage of the oceanic Hawaiian damselfly are found in swiftly flowing sections of streams, usually amid rocks and gravel in stream riffles (stream sections with sufficient gradient to create small standing waves) and small cascades on waterfalls (Williams 1936, pp. 321-322; Polhemus and Asquith 1996, p. 106). While capable of swimming, the naiads usually crawl among gravel or submerged vegetation. Older naiads frequently forage out of the actual stream channel and have been observed among wet moss on rocks, and wet rock walls and seeps (Williams 1936, pp. 321-323). Adults are very bold and strong flyers, and when disturbed frequently fly upward into the forest canopy overhanging the stream or waterfall (Williams 1936, p. 323; Polhemus 1994b, p. 48).

Historically, the oceanic Hawaiian damselfly occurred on both the leeward and windward sides of the Koolau and Waianae Mountains, and was known, but is currently extirpated, from approximately 16 general localities, including the Waianae Mountains and all leeward streams of the Koolau Mountains (Englund and Polhemus 1994, p. 8). The species now currently occupies between 7 and 10 sites above 300 ft (100 m) in elevation on the windward side of the Koolau Mountains at Kaaawa, Kahaluu, Koloa, and Sacred Falls, in the lowland mesic, lowland wet, and wet cliff ecosystems (TNC 2007; Polhemus 2007, pp. 237-239; HBMP 2008). Like the crimson and blackline Hawaiian damselflies, the oceanic Hawaiian damselfly is constrained to portions of streams not occupied by nonnative predatory fish—that is, stream portions above geologic or manmade barriers (e.g., waterfalls, steep gradients, dry stream midreaches, or constructed diversions). No estimates of population size for the oceanic Hawaiian damselfly are available.

Summary of Factors Affecting the 23 Species Proposed for Listing

Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations (50 CFR part 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors is discussed below.

In considering what factors might constitute threats to a species, we must look beyond the exposure of the species to a particular factor to evaluate whether the species may respond to that factor in a way that causes actual impacts to the species. If there is exposure to a factor and the species responds negatively, the factor may be a threat and, during the status review, we attempt to determine how significant a threat it is. The threat is significant if it drives, or contributes to, the risk of extinction of the species such that the species warrants listing as endangered or threatened as those terms are defined in the Act. However, the identification of factors that could impact a species negatively may not be sufficient to warrant listing the species under the Act. The information must include evidence sufficient to show that these factors are operative threats that act on the species to the point that the species meets the definition of endangered or threatened under the Act. That evidence is discussed below for each of the species proposed for listing in this proposed rule.

If we determine that the level of threat posed to a species by one or more of the five listing factors is such that the species meets the definition of either endangered or threatened under section 3 of the Act, we would then propose that species for listing when resources become available to do so. The Act defines an endangered species as “in danger of extinction throughout all or a significant portion of its range,” and a threatened species as “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” The threats to each of the individual 23 species are summarized in Table 2, and discussed in detail below. Factor B (overutilization) is not included in the table, as no threats to the species fall under this category. If these species are listed under the Act, the final rule will refer readers to the proposed rule for the detailed discussion of threats, rather than republishing that information in the

Federal Register

.

Ecosystem Approach

Each of the species proposed for listing in this proposed rule is adversely affected by the threats to the ecosystems on which it depends. There is information available on many of the threats that act on Hawaiian ecosystems, and for some ecosystems, there is a growing body of literature regarding these threats (e.g., non-native ungulates and invasive plant species). The best available information on ecosystem threats affecting the species therein is discussed below. Table 2 identifies the threats to the ecosystems and the individual species within those ecosystems that are affected by those threats. Information on threats specific to certain species is also discussed where necessary and available; however, we acknowledge that we do not completely understand all the threats to each species. Scientific research directed toward each of these species is limited because of their rarity and the generally challenging logistics associated with conducting field work in Hawaii (e.g., areas are typically remote, difficult to survey in a comprehensive manner, and the target species are exceptionally uncommon).

Ecosystem-Scale Threats That Affect the Proposed Species

The following constitutes a list of ecosystem-scale threats that affect the proposed species in all of the seven ecosystems on Oahu:

(1) Foraging and trampling of native plants by goats (

Capra hircus

), pigs (

Sus scrofa

) and other ungulates, which results in severe erosion of watersheds because these mammals inhabit terrain that is often steep and remote (Cuddihy and Stone 1990, p. 63). These events destabilize soils that support native plant communities, bury or damage native plants, and have adverse water quality effects due to runoff over exposed soils.

(2) Disturbance of soils by feral pigs, which creates fertile seedbeds for alien plants (Cuddihy and Stone 1990, p. 65).

(3) Increased nutrient availability as a result of pigs rooting in nitrogen-poor soils, which facilitates the establishment of alien weeds. Alien weeds are more adapted to nutrient rich soils than native plants (Cuddihy and Stone 1990, p. 63), and rooting activity creates open areas in forests allowing alien species to completely replace native stands.

(4) Ungulate destruction of seeds and seedlings of native plant species (Cuddihy and Stone 1990, p. 63), which facilitates the conversion of disturbed areas from native to nonnative vegetative communities.

(5) Rodent damage to plant propagules, seedlings, or native trees, which changes forest composition and structure (Cuddihy and Stone 1990, p. 67).

(6) Feeding or defoliation of native plants from alien insects, which reduces geographic ranges of some species because of damage (Cuddihy and Stone 1990, p. 71);

(7) Alien insect predation on native insects, which affects pollination of native plant species (Cuddihy and Stone 1990, p. 71).

(8) Significant changes in nutrient cycling processes because of large numbers of alien invertebrates such as earthworms, ants, slugs, isopods, millipedes, and snails, resulting in the changes to the composition and structure of plant communities (Cuddihy and Stone 1990, p. 73).

Each of the above threats is discussed in more detail below, and summarized in Table 2 below. The most-often cited effects of nonnative plants on native plant species are competition and displacement; competition may be for water or nutrients, or it may involve allelopathy (chemical inhibition of other plants). Alien plants may displace native species of plants by preventing their reproduction, usually by shading and taking up available sites for seedling establishment. Alien plant invasions may also alter entire ecosystems by forming monotypic stands, changing fire characteristics of native communities, altering soil-water regimes, changing nutrient cycling, or encouraging other nonnative organisms (Smith 1995; Vitousek

et al.

1987 in Cuddihy and Stone 1990, p. 74).

BILLING CODE 4310-55-P

EP02AU11.000

EP02AU11.001

EP02AU11.002

EP02AU11.003

BILLING CODE 4310-55-C

A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

The Hawaiian Islands are located over 2,000 mi (3,200 km) from the nearest continent. This isolation has allowed the few plants and animals that arrived in the Hawaiian Islands to evolve into many highly varied and endemic species (species that occur nowhere else in the world). The only native terrestrial mammals on the Hawaiian Islands are two bat taxa, the Hawaiian hoary bat (

Lasiurus cinereus semotus

), and an extinct, unnamed insectivorous bat (Ziegler 2002, p. 245). The native plants of the Hawaiian Islands therefore evolved in the absence of mammalian predators, browsers, or grazers; many of the native species lost unneeded defenses against threats such as mammalian predation and competition with aggressive, weedy plant species that are typical of mainland environments (Loope 1992, p. 11; Gagne and Cuddihy 1999, p. 45; Wagner

et al.

1999, pp. 3-6). For example, Carlquist (in Carlquist and Cole 1974, p. 29) notes that “Hawaiian plants are notably nonpoisonous, free from armament, and free from many characteristics thought to be deterrents to herbivores (oils, resins, stinging hairs, coarse texture).” In addition, species restricted to highly specialized locations or food sources (e.g., some Hawaiian damselflies) are particularly vulnerable to changes (from nonnative species, hurricanes, fire, and climate change) in their habitat (Carlquist and Cole 1974, pp. 28-29; Loope 1992, pp. 3-6; Stone 1992, pp. 88-102).

Habitat Destruction and Modification by Introduced Ungulates

Introduced mammals have greatly impacted the native vegetation, as well as the native fauna, of the Hawaiian Islands. Impacts to the native species and ecosystems of Hawaii accelerated following the arrival of Captain James Cook in 1778. The Cook expedition and subsequent explorers intentionally introduced a European race of pigs or boars and other livestock such as goats to serve as food sources for seagoing explorers (U.S. Geological Survey 1998, p. 752). The mild climate of the islands, combined with the lack of competitors or predators, led to the successful establishment of large populations of these introduced mammals, to the detriment of native Hawaiian species and ecosystems (Cox 1992, pp. 116-117). The presence of introduced alien mammals is considered one of the primary factors underlying the alteration and degradation of native vegetation and habitats on the island of Oahu (Cox 1992, pp. 118-119). Six of the seven ecosystems (lowland dry, lowland mesic, lowland wet, montane wet, dry cliff, and wet cliff) and their associated species are currently threatened by the destruction or degradation of habitat due to nonnative ungulates (hoofed mammals), including pigs (

Sus scrofa

) and goats (

Capra hircus

) (HBMP 2008). Only the coastal ecosystem on Oahu is not currently threatened by nonnative ungulates (S. Perlman, in litt. 2007).

Pigs have been described as the most pervasive and disruptive nonnative influence on the unique native forests of the Hawaiian Islands, and are widely recognized as one of the greatest current threats to forest ecosystems in Hawaii (Aplet

et al.

1991, p. 56; Anderson and Stone 1993, p. 195). European pigs, introduced to Hawaii by Captain James Cook in 1778, hybridized with domesticated Polynesian pigs, became feral, and invaded forested areas, especially wet and mesic forests and dry areas at high elevations. They are currently present on Kauai, Niihau, Oahu, Molokai, Maui, and Hawaii. The Hawaii Territorial Board of Agriculture and Forestry started a feral pig eradication project in the early 1900s that continued through 1958, removing 170,000 pigs from forests Statewide (Diong 1982 in Loope 1998, pp. 752-753).

These introduced pigs are extremely destructive and have both direct and indirect impacts on native plant communities. While rooting in the earth in search of invertebrates and plant material, pigs directly impact native plants by disturbing and destroying vegetative cover, and trampling plants and seedlings. They may also reduce or eliminate plant regeneration by damaging or eating seeds and seedlings. Further discussion of predation by nonnative ungulates is under Factor C, below. Pigs are a major vector for the establishment and spread of competing invasive nonnative plant species, by dispersing plant seeds on their hooves and coats as well as through the spread of their feces (Diong 1982, pp. 169-170), and by fertilizing the disturbed soil with their feces (Matson 1990, p. 245; Siemann

et al.

2009, p. 547). Pigs feed preferentially on the fruits of many nonnative plants, such as

Passiflora tarminiana

(banana poka) and

Psidium cattleianum

(strawberry guava), spreading the seeds of these invasive species through their feces as they travel in search of food. In addition, rooting pigs contribute to erosion by clearing vegetation and creating large areas of disturbed soil, especially on slopes (Smith 1985, pp. 190, 192, 196, 200, 204, 230-231; Stone 1985, pp. 254-255, 262-264; Medeiros

et al.

1986, pp. 27-28; Scott

et al.

1986, pp. 360-361; Tomich 1986, pp. 120-126; Cuddihy and Stone 1990, pp. 64-65; Aplet

et al.

1991, p. 56; Loope

et al.

1991, pp. 1-21; Gagne and Cuddihy 1999, p. 52).

Goats native to the Middle East and India were also successfully introduced to the Hawaiian Islands in the late 1700s. Actions to control goat populations began in the 1920s (Tomich 1986, pp. 152-153). Feral goats now occupy a wide variety of habitats on Oahu, where they consume native vegetation, trample roots and seedlings, accelerate erosion, and promote the invasion of alien plants that have greater competitive abilities (van Riper and van Riper 1982, pp. 34-35; Stone 1985, p. 261). Goats are able to access, and forage in, extremely rugged terrain, and they have a high reproductive capacity (Clarke and Cuddihy 1980, pp. C-19, C-20; Culliney 1988, p. 336; Cuddihy and Stone 1990, p. 64). Because of these factors, goats are believed to have completely eliminated some plant species from islands (Atkinson and Atkinson 2000, p. 21). Goats can be highly destructive to natural vegetation and contribute to erosion by: (1) Eating young trees and young shoots of plants before they can become established; (2) creating trails that can damage native vegetative cover, destabilize substrate and create gullies that convey water; and (3) dislodging stones from ledges that can cause rockfalls and landslides that damage vegetation below (Cuddihy and Stone 1990, pp. 63-64).

The species proposed for listing dependent on the lowland dry, lowland mesic, lowland wet, montane wet, dry cliff, and wet cliff ecosystems are exposed to direct and indirect negative impacts of feral ungulates (pigs and goats), which result in the destruction and degradation of habitat for these native Oahu species. The effects of these nonnative animals include: (1) The destruction of vegetative cover; (2) trampling of plants and seedlings; (3) direct consumption of native vegetation; (4) soil disturbance; (5) dispersal of alien plant seeds on hooves, coats, and through the spread of seeds in feces; and (6) the creation of open, disturbed areas conducive to further invasion by nonnative pest plant species. All of these impacts lead to the subsequent conversion of a plant community dominated by native species to one dominated by nonnative species (See “

Habitat Destruction and Modification by Nonnative Plants,”

below). In addition, because these mammals

inhabit terrain that is often steep and remote (Cuddihy and Stone 1990, p. 59), foraging and trampling contributes to severe erosion of watersheds and degradation of streams. As early as 1900, there was increasing concern expressed about the integrity of island watersheds, due to effects of ungulates and other factors, leading to establishment of a professional forestry program emphasizing soil and water conservation (Nelson 1989, p. 3).

Habitat Destruction and Modification by Nonnative Plants

Native vegetation on all of the main Hawaiian Islands has undergone extreme alteration because of past and present land management practices, including ranching, the deliberate introduction of nonnative plants and animals, and agricultural development (Cuddihy and Stone 1990, pp. 27, 58). The original native flora of Hawaii (species that were present before humans arrived) consisted of about 1,000 taxa, 89 percent of which were endemic. Over 800 plant taxa have been introduced from outside Hawaii, and nearly 100 of these have become pests (e.g., injurious plants) (Smith 1985, p. 180; Cuddihy and Stone 1990, p. 73; Gagne and Cuddihy 1999, p. 45). Of these 100 nonnative plant species, over 50 species have altered the habitat of 20 of the 23 species proposed for listing on Oahu. Some of these plants were brought to Hawaii by various groups of people, for food or cultural reasons, to reforest native forests destroyed by grazing feral and domestic animals, for pasture for domestic animals, and for other agricultural purposes. Other plants were brought to Hawaii for their potential horticultural value (Scott

et al.

1986, pp. 361-363; Cuddihy and Stone 1990, p. 73).

Nonnative plants adversely impact native habitat in Hawaii, including the seven Oahu ecosystems and the 20 plant species identified in this proposed rule, by: (1) Modifying the availability of light; (2) altering soil-water regimes; (3) modifying nutrient cycling; (4) altering fire characteristics of native plant communities (e.g., successive fires that burn farther and farther into native habitat, destroying native plants and removing habitat for native species by altering microclimatic conditions to favor alien species); and (5) ultimately, converting native-dominated plant communities to nonnative plant communities (Smith 1985, pp. 180-181; Cuddihy and Stone, 1990, p. 74; D'Antonio and Vitousek 1992, p. 73; Vitousek

et al.

1997, p. 6). Nonnative plants (and animals) have contributed to the extinction of native species in the lowlands of Hawaii and have been a primary cause of extinction in upland habitats (Vitousek

et al.

1987, in Cuddihy and Stone 1990, p. 74). The most-often cited effects of nonnative plants on native plant species are displacement through competition. Competition may be for water or nutrients, or it may involve allelopathy (chemical inhibition of other plants) (Smith 1985, in Cuddihy and Stone 1990, p. 74). Nonnative plants may also displace native species by preventing their reproduction, usually by shading and taking up available sites for seedling establishment (Vitousek

et al.

1987, in Cuddihy and Stone 1990, p. 74).

Alteration of fire regimes clearly represents an ecosystem-level change caused by the invasion of nonnative grasses (D'Antonio and Vitousek 1992, p. 73). The grass life form supports standing dead material that burns readily, and grass tissues have large surface/volume ratios and can dry out quickly (D'Antonio and Vitousek 1992, p. 73). The flammability of biological materials is determined primarily by their surface/volume ratio and moisture content, and secondarily by mineral content and tissue chemistry (D'Antonio and Vitousek 1992, p. 73). The finest size classes of material (mainly grasses) ignite and spread fires under a broader range of conditions than do woody fuels or even surface litter (D'Antonio and Vitousek 1992, p. 73). The grass life form allows rapid recovery following fire; there is little above-ground structural tissue, so almost all new tissue fixes carbon and contributes to growth (D'Antonio and Vitousek 1992, p. 73). Grass canopies also support a microclimate in which surface temperatures are hotter, vapor pressure deficits are larger, and the drying of tissues more rapid than in forests or woodlands (D'Antonio and Vitousek 1992, p. 73). Thus, conditions that favor fire are much more frequent in grasslands (D'Antonio and Vitousek 1992, p. 73). In summary, nonnative plants directly and indirectly affect the plant species proposed for listing by modifying or destroying their terrestrial habitat. Below, we have organized a list of nonnative plants by their ecosystems, followed by a discussion of the specific negative effects of those nonnative plants on the proposed species.

Nonnative Plants in the Coastal Ecosystem

Nonnative plant threats to

Bidens amplectens,

the only species proposed for listing in this proposed rule that inhabits the coastal ecosystem on Oahu, include the understory and subcanopy species

Asystasia gangetica

(Chinese violet),

Atriplex semibaccata

(Australian saltbush),

Leucaena leucocephala

(koa haole),

Pluchea indica

(Indian fleabane),

P. carolinensis

(sourbush), and

Verbesina encelioides

(golden crown-beard) (DOFAW 2007, pp. 20-22, 54-58; HBMP 2008). Nonnative canopy species includes

Prosopis pallida

(kiawe) (DOFAW 2007, pp. 20-22, 54-58; HBMP 2008). In addition,

Bidens amplectens

is threatened by several nonnative grasses such as

Cenchrus ciliaris

(buffelgrass),

Chloris barbata

(swollen fingergrass),

Digitaria insularis

(sourgrass), and

Panicum maximum

(guinea grass) in this ecosystem (DOFAW 2007, pp. 20-22, 54-58; HBMP 2008). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to

Bidens amplectens

in this ecosystem.

Nonnative Plants in the Lowland Dry Ecosystem

Nonnative plant threats to

Bidens amplectens, Doryopteris takeuchii,

and

Pleomele forbesii,

the three species proposed for listing in this proposed rule that inhabit the lowland dry ecosystem include the understory and subcanopy species

Leonotis nepetifolia

(lion's ear),

Passiflora foetida

(love-in-a-mist),

P. suberosa

(huehue haole), and

Stapelia gigantea

(giant toad plant) (HBMP 2006; Perlman 2007a, p. 3; HBMP 2008). Canopy species include

Aleurites moluccana

(kukui),

Grevillea robusta

(silk oak),

Leucaena leucocephala, Psidium cattleianum,

P. guajava

(common guava),

Schinus terebinthifolius

(Christmas berry), and

Syzygium cumini

(Java plum) (Perlman 2007a, p. 7; HBMP 2006; HBMP 2008). In addition,

Bidens amplectens, Doryopteris takeuchii,

and

Pleomele forbesii

are threatened by several nonnative grasses such as

Andropogon virginicus

(broomsedge),

Cenchrus ciliaris, Melinis minutiflora

(molasses grass),

Panicum maximum,

and

Pennisetum setaceum

(fountain grass) in this ecosystem (HBMP 2006; Perlman 2007a, p. 3; HBMP 2008). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to the three species proposed for listing that depend on this ecosystem.

Nonnative Plants in the Lowland Mesic Ecosystem

Nonnative plant threats to the eight plant species (

Cyanea calycina, Cyanea lanceolata,

Cyrtandra waiolani, Melicope makahae,

Platydesma cornuta

var.

decurrens, Pleomele

forbesii, Pteralyxia macrocarpa,

and

Tetraplasandra lydgatei

) proposed for listing in this proposed rule that inhabit the lowland mesic ecosystem include the understory and subcanopy species

Ageratina riparia

(Hamakua pamakani),

Ardisia elliptica

(shoebutton ardisia),

Blechnum appendiculatum

(no common name (NCN)),

Buddleia asiatica

(dog tail),

Clidemia hirta

(Koster's curse),

Erigeron karvinskianus

(daisy fleabane),

Kalanchoe pinnata

(air plant),

Lantana camara

(lantana),

Passiflora suberosa, Rubus argutus

(prickly Florida blackberry), and

R. rosifolius

(thimbleberry) (TNC 1997, pp. 10, 15; HBMP 2008). Canopy species include

Aleurites moluccana, Ficus microcarpa

(Chinese banyan),

Grevillea robusta, Heliocarpus popayanensis

(moho),

Morella faya

(firetree),

Psidium cattleianum, P. guajava,

Schefflera actinophylla

(octopus tree),

Schinus terebinthifolius, Syzygium cumini,

S. jambos

(rose apple),

Tecoma stans

(yellow elder), and

Toona ciliata

(Australian red cedar). An additional threat is the nonnative grass

Melinus minutiflora

(TNC 1997, p. 15; Motley 2005, p. 109; HBMP 2008). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to all eight of the species proposed for listing that are dependent on this ecosystem.

Nonnative Plants in the Lowland Wet Ecosystem

Nonnative plant threats to the 14 plant species (

Cyanea calycina, C. lanceolata,

C.

purpurellifolia, Cyrtandra gracilis,

C. kaulantha,

C. sessilis,

C. waiolani, Melicope hiiakae, M. makahae,

Platydesma cornuta

var. cornuta,

Pleomele forbesii,

Psychotria hexandra

ssp.

oahuensis, Pteralyxia

macrocarpa,

and

Zanthoxylum oahuense

) proposed for listing in this proposed rule that inhabit the lowland wet ecosystem include the understory and subcanopy species

Ageratina riparia, Blechnum appendiculatum,

Buddleia asiatica, Clidemia hirta,

Erechtites valerianifolia

(fireweed),

Kalanchoe pinnata, Passiflora suberosa,

Pterolepis glomerata

(NCN),

Rubus argutus, R. rosifolius,

and

Sphaeropteris cooperi

(Australian tree fern), and the canopy species

Aleurites moluccana, Ardisia elliptica,

Chrysophyllum oliviforme

(satinleaf),

Heliocarpus popayanensis, Leptospermum scoparium

(tea tree),

Morella faya, Pimenta dioica

(allspice),

Psidium cattleianum, P. guajava,

and

Schinus terebinthifolius

(TNC 1997, p. 10; U.S. Army 2006; HBMP 2008). Nonnative grasses that are threats to the 14 plant species proposed for listing in this ecosystem are

Andropogon virginicus, Axonopus fissifolius

(narrow-leaved carpetgrass),

Melinus minutiflora, Oplismenus hirtellus

(basketgrass),

Sacciolepis indica

(glenwood grass), and

Urochloa mutica

(California grass) (TNC 1997, p. 10; Erickson and Puttock 2006, p. 270; U.S. Army 2006). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to the 14 plants proposed for listing that inhabit this ecosystem.

Nonnative Plants in the Montane Wet Ecosystem

Nonnative plant threats to

Cyanea calycina

and

Melicope christophersenii,

proposed for listing in this proposed rule that inhabit the montane wet ecosystem include the understory and subcanopy species

Clidemia hirta

and

Rubus argutus,

and the canopy species

Psidium cattleianum

(HBMP 2008). These nonnative plant species pose a serious threat (See “Specific Nonnative Plant Species Impacts,” below) to the two proposed species dependent on this ecosystem.

Nonnative Plants in the Dry Cliff Ecosystem

Nonnative plant threats to the five plant species (

Korthasella degeneri, Melicope

makahae, Platydesma cornuta

var.

decurrens, Pleomele forbesii,

and

Pteralyxia macrocarpa

) which are proposed for listing in this proposed rule and that inhabit the dry cliff ecosystem include the understory and subcanopy species

Ageratina riparia, Blechnum appendiculatum,

Clidemia hirta, Erigeron karvinskianus,

Kalanchoe pinnata, Lantana camara,

Passiflora suberosa,

and

Sphaeropteris cooperi,

and the canopy species

Acacia confusa

(Formosa koa),

Aleurites moluccana, Grevillea robusta,

Leucaena leucocephala, Melia azederach

(Chinaberry),

Psidium cattleianum, P. guajava,

Schinus terebinthifolius, Syzygium cumini,

Tecoma stans,

and

Toona ciliata

(HBMP 2008). Nonnative grasses that are a threat to this ecosystem include

Digitaria insularis

(sourgrass),

Ehrharta stipoides

(meadow ricegrass),

Melinus minutiflora, Panicum maximum,

and

Paspalum conjugatum

(Hilo grass) (HBMP 2008). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to the five species proposed for listing that are dependent on this ecosystem.

Nonnative Plants in the Wet Cliff Ecosystem

Nonnative plant threats to the seven plant species (

Cyanea calycina, C.

purpurellifolia, Cyrtandra

kaulantha, C.

sessilis, Melicope christophersenii,

Psychotria hexandra

ssp.

oahuensis, Pteralyxia macrocarpa

) proposed for listing in this proposed rule that inhabit the wet cliff ecosystem include the understory and subcanopy species

Blechnum appendiculatum, Clidemia hirta,

Erechtites valerianifolia, Erigeron karvinskianus,

Passiflora suberosa, Pterolepis glomerata,

Rubus argutus, R. rosifolius,

and the canopy species

Ardisia elliptica, Buddleia asiatica,

Heliocarpus popayanensis, Psidium cattleianum,

P. guajava, Schinus terebinthifolius,

and

Toona ciliata

(HBMP 2008). Nonnative grasses that are a threat to this ecosystem include

Axonopus fissifolius, Melinus minutiflora,

Oplismenus hirtellus,

and

Paspalum conjugatum

(HBMP 2008). These nonnative plant species pose a serious threat (see “

Specific Nonnative Plant Species Impacts,”

below) to all seven of the proposed plant species dependent on this ecosystem.

Specific Nonnative Plant Species Impacts

To reiterate, nonnative plants represent a serious and ongoing threat to each of the 20 plant species proposed for listing in this proposed rule throughout their ranges by destroying and modifying habitat. Nonnative plants can adversely impact microhabitat by modifying the availability of light and nutrient cycling processes, and by altering soil-water regimes. They can also alter fire characteristics of native plant habitat, leading to incursions of fire-tolerant, nonnative plant species in native habitat. Nonnative plants outcompete native plants by growing faster, and some may release chemicals that inhibit the growth of other plants. By outcompeting native plants, nonnative plants convert native-dominated plant communities to nonnative plant communities (Cuddihy and Stone 1990, p. 74; Vitousek 1992, pp. 33-35). The following list provides a brief description of specific nonnative plants that present a threat to the species proposed for listing in this proposed rule because they threaten the ecosystems in which the plant species occur.

•

Acacia confusa

is a tree introduced to Hawaii from Taiwan and the Philippine Islands about 1915 by the Board of Agriculture and Forestry and the Hawaiian Sugar Planter's Association for use as a windbreak (Geesink

et al.

1999, p. 641). This species forms monotypic stands at lower elevations that prevent establishment of native plants. Seeds present in the ground germinate profusely after fire, outcompeting native plants (Pacific

Island Ecosystems at Risk (PIER) 2008a). This species occurs in dry to mesic disturbed habitats (Wagner

et al.

1999, p. 640).

•

Ageratina riparia

is a subshrub that spreads from a creeping rootstock (Wagner

et al.

1999, p. 255). This species forms dense mats, preventing regeneration of native plants (Davis

et al.

1992, p. 427), and occurs in dry, disturbed habitats and mesic and wet forests (Wagner

et al.

1999, p. 255).

•

Aleurites moluccana

is a spreading, tall tree native to Malesia, and considered a Polynesian introduction to Hawaii. It is now a significant component of the mesic valley vegetation from sea level to 2,300 ft (700 m) on all the main islands (Wagner

et al.

1999, p. 598). According to the Hawaii Weed Risk Assessment for

A. moluccana,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2008b). The species tolerates a wide range of soil conditions and forms dense thickets, which increases its competitive abilities over native plants. This species occurs in mesic valley habitats (Wagner

et al.

1999, p. 599).

•

Andropogon virginicus

is a fire-adapted bunch grass with seeds that are easily distributed by wind, clothing, vehicles, and feral animals (Smith 1989, p. 63). It can outcompete and displace native plants. Some research suggests that this species may also release allelopathic substances (chemicals that inhibit growth of other plants) that dramatically decrease the reestablishment of native plants (Rice 1972, p. 752). This species has become dominant in areas subjected to natural or human-induced fires (Wagner

et al.

1999, p. 77). This species is on the Hawaii State noxious weed list (HAR Title 4, Subtitle 6, Chapter 68), and occurs in disturbed, dry to mesic forests and shrubland habitats, especially on ridges (Wagner

et al.

1999, p. 1497).

•

Ardisia elliptica

is a branched shrub native to Sri Lanka that is now naturalized (i.e., introduced by man from another area, and established and reproducing itself in the wild) in Hawaii (Wagner

et al.

1999, pp. 932-933). This species is shade-tolerant and can rapidly form dense, monotypic stands, preventing establishment of other species (Global Invasive Species Database (GISD) 2005). Its fruit are attractive to birds, which can then spread the seeds over the landscape. According to the Hawaii Weed Risk Assessment for

A. elliptica,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2008c). This species occurs in mesic forest habitats and the lower portions of wet forests (Wagner

et al.

1999, p. 933).

•

Asystasia gangetica,

a perennial herb native to India, Malay Peninsula, and Africa, is naturalized in disturbed habitats in Hawaii. This species can grow over shrubs and smother all vegetation in the herbaceous layer, covering native plants and preventing their establishment (Smith 1985, p. 185). According to the Hawaii Weed Risk Assessment for

A. gangetica,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2009). This species occurs in low-elevation, disturbed habitats (Wagner

et al.

1999, p. 168).

•

Atriplex semibaccata

is a drought- and saline-tolerant, low-growing shrub, that forms dense spreading mats that displace native plants. It was introduced to Hawaii around 1895, as an experimental forage grass plant for cattle, and is now naturalized in dry to seasonally wet areas (Wagner

et al.

1999, p. 535). The seeds are attractive to fruit eaters, which may help disperse this plant (California Invasive Plant Council 2006). This species occurs in dry to seasonally wet habitat areas (Wagner

et al.

1999, p. 535).

•

Axonopus fissifolius

is a pasture grass that forms dense mats with tall foliage. This species does well in soils with low nitrogen levels, and can outcompete other grasses in wet forests and bogs. The species is not subject to any major diseases or insect pests, and recovers quickly from fire. The seeds are readily spread by water, vehicles, and grazing animals (O'Connor 1999, pp. 1,500-1,502; Cook

et al.

2005, p. 4). This species occurs in wet pastures, disturbed wet forests, and bogs (Wagner

et al.

1999, p. 1,502).

•

Blechnum appendiculatum

is a fern with fronds to 23 in (60 cm) long that forms large colonies in closed canopy mesic forests, especially on rocky substrate. It occurs in all but the most extreme habitats (Palmer 2003, p. 81).

•

Buddleia asiatica

is a shrub or small tree that can tolerate a wide range of habitats, forms dense thickets, and is rapidly spreading into wet forest and even lava and cinder substrate areas in Hawaii, displacing native vegetation (Wagner

et al.

1999, p. 415; PIER 2008d). This species occurs in lava, cinder fields, and wet forest habitats (Wagner

et al.

1999, p. 416).

•

Cenchrus ciliaris

is native to Africa and tropical Asia and is naturalized in Hawaii. It is a fire-adapted grass that provides fuel for fires and recovers quickly, increasing its cover with each succeeding fire (PIER 2007a), because it can reproduce through vegetative fragmentation and be dispersed by animals or other vectors, increasing its competitive abilities over native plants. This species occurs in dry areas and sandy soil, in a variety of habitat types (Wagner

et al.

1999, p. 1,512).

•

Chloris barbata,

native to Central America, West Indies, and South America, is widely naturalized in Hawaii (O'Connor 1999, p. 1,514). This species first evolved resistance to Group C1/5 herbicides in Hawaii in 1987. The species infests roadsides and sugarcane plantations, and encroaches on native habitat (WeedScience.com 2009; HBMP 2008). According to the Hawaii Weed Risk Assessment for

C. barbata,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2008e) because of its ability to outcompete native species. This species occurs in dry disturbed areas, roadsides, vacant lots, and pastures (Wagner

et al.

1999, p. 1,514).

•

Chrysophyllum oliviforme

is a small tree native to the United States (Florida), West Indies, and Central America, and is naturalized in Hawaii (Pennington 1999, p. 1,231; PIER 2006a). Birds easily disperse the fleshy fruit, and the species becomes a dominant component over native forest (Pennington 1999, p. 1,231; Maui Land and Pineapple Company 2002, pp. A 1-4). According to the Hawaii Weed Risk Assessment for

C. oliviforme,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2006a). This species has been documented in low-elevation moist forests.

•

Clidemia hirta

is a noxious shrub in the Melastomataceae family that forms a dense understory, shades out native plants and prevents their regeneration, and is considered a significant nonnative plant threat (Wagner

et al.

1985, p 41; Smith 1989, p. 64). All plants in the Melastomataceae family are legally designated “noxious” in the State of Hawaii (HAR Title 4, Subtitle 6, Chapter 68). This species has been documented in forests and pastures (

http://www.ctahr.hawaii.edu/invweed/weedsHI.html

).

•

Digitaria insularis

is a densely tufted, perennial grass that is 3.2 to 5 ft (100 to 150 cm) tall. It is native to the neotropics, and is widely naturalized on Hawaiian and other Pacific islands, and in Malesia (O'Connor 1999, p. 1,531). It forms dense mats, crowding out native species (Motooka

et al.

2003a), and occurs in lawns and pastures (Wagner

et al.

1999, p. 1,531).

•

Ehrharta stipoides

is a grass that creates a thick mat in which other species cannot regenerate; its seeds are easily dispersed by awns (slender, terminal bristle-like process found at the

spikelette in many grasses) that attach to fur or clothing (U.S. Army Garrison 2006, p. 2-1-20). This species has been documented in dry to mesic areas between elevations of 330 to 1700 ft (100 to 500 m)

Erechtites valerianifolia

is

a tall (up to 8 ft (2.5 m)), widely-distributed annual herb that produces thousands of wind-dispersed seeds, and outcompetes native plants (Wagner

et al.

1999, p. 314). This species occurs in relatively wet disturbed habitats (Wagner

et al.

1999, p. 314).

•

Erigeron karvinskianus

reproduces and spreads rapidly by stem layering and regrowth of broken roots to form dense mats.

This species crowds out and displaces ground-level plants (Weeds of Blue Mountains Bushland 2006), and occurs in moderately wet habitats (Wagner

et al.

1999,

p.

315).

•

Ficus microcarpa

is a very large, spreading tree with numerous aerial roots that form columnar stems. It is epiphytic and can germinate on other trees, eventually strangling its host, and can shade out native plants with its broad canopy. Seeds are spread by birds (Motooka

et al.

2003b). This species occurs in highly disturbed low-elevation habitats (Wagner

et al.

1999, p. 926).

•

Grevillea robusta

is a large evergreen tree native to Australia. Over two million trees were planted in Hawaii between 1919 and 1959 in an effort to reduce erosion and to provide timber. The leaves produce an allelopathic substance that inhibits the establishment of all species (Smith 1985, p. 191). This species has been documented in dry and moist forests, and open areas.

•

Heliocarpus popayanensis

is a tree native to Mexico and Argentina, planted extensively in Hawaii by foresters beginning in 1941, and has since escaped into wet forests at low to mid elevations (Wagner

et al.

1999, p. 1,292). The seeds are dispersed by wind, and

H. popayanensis

is becoming a dominant tree in some forest areas on Oahu (Smith 1998). The species grows rapidly and spreads readily in disturbed wetter mesic forest habitats, where it can outcompete native vegetation (Mootka 2003c). This species occurs in disturbed forest habitats (Wagner

et al.

1999, p. 1292).

•

Kalanchoe pinnata

is a succulent perennial plant with hollow stems that can form dense stands that prevent reproduction of native species. It can also reproduce by vegetative means at indents along the leaf margin (Motooka

et al.

2003c). This species occurs in low-elevation, dry to mesic, disturbed habitats (Wagner

et al.

1999, p. 568).

•

Lantana camara

was brought to Hawaii as an ornamental plant, and is an aggressive, thorny, thicket-forming shrub that is now found on all of the main islands (Davis

et al.

1992, p. 412; Wagner

et al.

1999, p. 1,320). It forms dense impenetrable stands that negatively affect native plants through competition (Mootka 2003d), and occurs in mesic forest, dry shrubland, and dry/disturbed low elevation habitats (Wagner

et al.

1999, p. 1320).

•

Leonotis nepetifolia

is a coarse annual herb that is widely naturalized and forms dense thickets that displace native plants. According to the Hawaii Weed Risk Assessment for

L. nepetifolia,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2006b). This species occurs in low-elevation, dry to occasionally wet, disturbed habitats (Wagner

et al.

1999, p. 803).

•

Leptospermum scoparium

is a shrub or small tree native to New Zealand and Australia, which is now widely naturalized in Hawaii. It forms thickets that crowd out other plants, and is allelopathic (produces chemicals that inhibit growth of other plants) (Smith 1985, p. 193)). This species occurs in disturbed, mesic to wet, forest habitats (Wagner

et al.

1999, p. 963).

•

Leucaena leucocephala,

a shrub native to the neotropics, is now found on all of the main Hawaiian Islands and Midway atoll. It is an aggressive competitor that often forms the dominant element of the vegetation in low-elevation, dry, disturbed areas (Geesink

et al.

1999, pp. 679-680).

•

Melia azedarach

is a small, deciduous tree native to southwestern Asia that is invading forests, fence lines, and disturbed areas in Hawaii. Its fast growth and rapidly spreading thickets make it a significant pest plant by shading out and displacing native vegetation (University of Florida 2008). Feral pigs and fruit-eating birds further distribute the seeds (Stone 1985, pp. 194-195). According to the Hawaii Weed Risk Assessment for

M. azedarach,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2008f). This species occurs in dry, disturbed habitats (Wagner

et al.

1999, p. 918).

•

Melinus minutiflora

is a spreading, perennial grass that forms dense mats that can fuel more intense fires that destroy native plants (Cuddihy and Stone 1990, p. 89; O'Connor 1999, p. 1,562). This species occurs in dry to mesic habitats, in disturbed and usually open areas (Wagner

et al.

1999, p. 1563).

•

Morella faya

is an evergreen shrub or small tree that forms monotypic stands, has the ability to fix nitrogen, and alters the successional ecosystems in areas it invades, displacing native vegetation through competition. It is also a prolific fruit producer (average of 400,000 fruits per individual shrub or tree per year), and the fruit are spread by frugivorous birds and feral pigs (Vitousek 1990, pp. 8-9; Wagner

et al.

1999, p. 931; PIER 2008g). This species is on the Hawaii State noxious weed list (HAR Title 4, Subtitle 6, Chapter 68). The species has been documented in forested habitats (

http://www.hawaiiinvasivespecies.org/pests/firetree.html

).

•

Oplismenus hirtellus

is a perennial grass that forms a dense groundcover, is sometimes climbing, and roots at the nodes, enabling its rapid spread. It also has sticky seeds that attach to visiting animals and birds that then carry them to new areas where they are deposited, resulting in the spread of this species (O'Connor 1999, p. 1,565; Johnson 2005). The species displaces native plants on forest floors and trailsides (Motooka 2003e), and occurs in shaded mesic valleys, mesic forest, and disturbed wet forest habitats (Wagner

et al.

1999, p. 1,565).

•

Panicum maximum

is cultivated as an important forage grass throughout the tropics and is naturalized in Hawaii (O'Connor 1999, p. 1,569). This tall grass produces profuse seeds that are spread by wind, birds, and flowing water. This plant is strongly allelopathic (PIER 2007b), and can form dense stands that exclude native species. It regenerates rapidly from underground rhizomes after a fire (PIER 2007b). This species has been documented in open disturbed areas of forests, wastelands, and roadsides (

http://www.ctahr.hawaii.edu/invweed/weedsHi.html

).

•

Paspalum conjugatum

is a perennial grass that is found in wet habitats, and forms a dense ground cover. Its small hairy seeds are easily transported on humans and animals or are carried by the wind through native forests, where it establishes and displaces native vegetation (Tomich 1986, p. 125; Cuddihy and Stone 1990, p. 83; PIER 2007c; Motooka

et al.

2003d). This species occurs in moist to wet disturbed habitats (Wagner

et al.

1999, p. 1,576).

•

Passiflora foetida i

s a vine with glandular hairs that give the plant a fetid odor. This species is naturalized in Hawaii, and grows over and covers low vegetation that prevents or delays establishment of native species. Its fruit are eaten and spread by birds (Escobar 1999, p. 1,011; GISD 2006). This species occurs in disturbed sites and rock outcrop habitats (Wagner

et al.

1999, p. 1,011).

•

Passiflora suberosa

has many-seeded purple fruits that are dispersed widely by birds. It is an aggressive vine that grows over and smothers shrubs, small trees, and ground layer vegetation, and sometimes upper canopy layer vegetation (Smith 1985, pp. 191-192). This species occurs in grassland, shrubland, open dry forest, mesic forest, and exposed ridge habitats (Wagner

et al.

1999, p. 1,014).

•

Pennisetum setaceum

is a grass that is an aggressive colonizer, and outcompetes most native species. This species is also fire-adapted and burns swiftly and hot, causing extensive damage to the surrounding habitat (O'Connor 1999, p. 1,581). This species occurs in dry open places, barren lava flows, and cinder fields (Wagner

et al.

1999, p. 1,578).

•

Pimenta dioica

is a tree with sticky grape-like seeds that are spread by birds. Widely cultivated, this species was introduced to Hawaii in 1885, and is believed to be naturalized on Kauai and perhaps on Oahu (Staples and Herbst 2005, p. 427). According to the Hawaii Weed Risk Assessment for

P. dioica,

this species has a high risk of invasiveness or a high risk of becoming a serious pest (PIER 2008h). The species forms dense thickets, tolerates a wide range of soil conditions, and has propagules that survive passage through bird digestive systems. These capabilities increase its competitive ability over native plants. This species has been documented in dry and moist forests up to elevation 3,000 ft.

•

Pluchea indica

is native to southern Asia, and

P. carolinensis

is native to Mexico, the West Indies, and South America (Wagner

et al.

1999, p. 351). These 3- to 6 ft- (1- to 2-m) tall, fast-growing shrubs form thickets in dry habitats and can tolerate saline conditions. They are widespread in Hawaii from coastal areas up to almost 3,000 ft (900 m). The seeds are wind-dispersed (Francis 2006). The species is adapted to a wide variety of soils and sites, tolerates excessively well to poorly drained soil conditions, the full range of soil textures, acid and alkaline reactions, salt and salt spray, and compaction. It quickly invades burned areas, but being early successional, it is soon replaced by other species. These adaptive capabilities increase the species' competitive abilities over native plants. This species occurs in low-elevation, dry, coastal habitats (Wagner

et al.

1999, p. 351).

•

Pluchea carolinensis

is native to Mexico, the West Indies, and northern South America. The species has naturalized in Hawaii, usually in relatively dry, coastal areas, but ranging up to 3,000 ft (900 m) in mesic to wet forest. The species was first collected on Oahu in 1931 (Wagner

et al.,

1999. p. 351). This fast-growing shrub forms thickets in dry habitats. The seeds are wind-dispersed. Its resistance to fire depends on the intensity of the fire. It generally regenerates from basal shoots. Some biological control agents have been introduced but they have not been effective (

http://www.botany.hawaii.edu/faculty/cw_smith/plu_sym.htm

).

•

Prosopis pallida

was introduced to Hawaii in 1828, and its seeds were used as fodder for ranch animals. This species became a dominant component of the vegetation in low-elevation, dry, disturbed sites, as it is well adapted to dry habitats. It overshadows other vegetation and the deep tap roots use all available water. This plant fixes nitrogen and can outcompete native species (Geesink

et al.

1999, pp. 692-693; PIER 2006c). This species occurs in low-elevation, dry, disturbed habitats; behind beaches; on raised limestone reefs; on dry slopes and bulches; and in degraded dry forest habitats (Wagner

et al.

1999, p. 693).

•

Psidium cattleianum

is a tall shrub or tree that forms dense stands in which few other plants can grow, displacing native vegetation through competition. The fruit is eaten by pigs and birds that disperse the seeds throughout the forest (Smith 1985, p. 200; Wagner

et al.

1985, p. 24). This species occurs in disturbed, mesic forest and wet forest habitats (Wagner

et al.

1999, p. 970).

•

Psidium guajava

is a shrub or tree that forms dense stands in disturbed forest. The seeds are spread by feral pigs and alien birds, and it can also regenerate from underground parts by suckering (Wagner

et al.

1999, p. 972). Seeds are dispersed throughout the forest, which facilitates competition with native plants. This species occurs in disturbed, dry, mesic and wet, forest habitats (Wagner

et al.

1999, p. 972).

•

Pterolepis glomerata

is

a member of the Melastomataceae family. The basis for its classification as invasive are the plant's germination rates, rapid growth, early maturity, ability of fragments to root, possible asexual reproduction, and seed dispersal by birds (University of Florida Herbarium 2006). Because of these attributes, it displaces native vegetation through competition. This species is on the Hawaii State noxious weed list (HAR Title 4, Subtitle 6, Chapter 68). This species occurs in disturbed, mesic to wet habitats and trail margins (Wagner

et al.

1999, p. 913).

•

Rubus argutus

is a prickly bramble with long, arching stems that reproduces both vegetatively and by seed. It readily sprouts from underground runners, and is quickly spread by frugivorous birds (Tunison 1991, p. 2; Wagner

et al.

1999, p. 1,107; U.S. Army 2006, pp. 2-1-21, 2-1-22). This species, which displaces native vegetation through competition, is on the Hawaii State noxious weed list (HAR Title 4, Subtitle 6, Chapter 68). This species occurs in mesic to wet forest and subalpine grassland habitats (Wagner

et al.

1999, p. 1,107).

•

Rubus rosifolius

is an erect to trailing shrub that forms dense thickets and outcompetes native plant species. It easily reproduces from roots left in the ground, and seeds are spread by birds and feral animals (GISD 2008a; PIER 2008i). This species occurs in disturbed, mesic to wet, forest habitat (Wagner

et al.

1999, p. 1,110).

•

Sacciolepis indica

is an annual grass that invades disturbed and open areas in wet habitats, and outcompetes native plants. The seeds are dispersed by sticking to animal fur (University of Hawaii 1998). This species occurs in open, wet areas such as grasslands, ridge crests, openings in wet forest, and along trails (Wagner

et al.

1999, p. 1589).

•

Schefflera actinophylla

is a tree native to Australia and New Guinea, and now naturalized in Hawaii (Lowry 1999, p. 232). This species is shade tolerant and can spread into undisturbed forests, forming dense thickets.

Schefflera actinophylla

grows epiphytically, strangling host trees, and its numerous seeds are readily dispersed by birds (PIER 2008j). This species occurs in low-elevation, disturbed, mesic habitats (Wagner

et al.

1999, p. 232).

•

Schinus terebinthifolius

forms dense thickets in all habitats, and its red berries are attractive to birds (Smith 1989, p. 63).

Schinus

seedlings grow very slowly and can survive in dense shade, exhibiting vigorous growth when the canopy is opened after a disturbance (Brazilian Pepper Task Force 1997). Because of these attributes,

S. terebinthifolius

is able to displace native vegetation through competition. This species occurs in disturbed, mesic habitats (Wagner

et al.

1999, p. 195).

•

Sphaeropteris cooperi

is a tree fern native to Australia that was brought to Hawaii for use in landscaping (Medeiros

et al.

1992, p. 27). It can achieve high densities in native Hawaiian forests, grows up to 1 ft (0.3 m) in height per year (Jones and Clemesha 1976, p 56), and can displace native species. Understory disturbance by pigs facilitates the establishment of this species (Medeiros

et al.

1992, p. 30), and

it has been known to spread over 7 mi (12 km) through windblown dispersal of spores from plant nurseries (Medeiros

et al.

1992, p. 29). This species has been documented in rain forest, moist forest, and openings in wet and moist areas.

•

Stapelia gigantea

is a succulent, cactus-like plant native to tropical Africa and Mozambique (Wagner

et al.

1999, p. 241). It can compete with native species for space and water in exposed areas. This species has been documented in dry forests and open areas.

•

Syzygium cumini

is a tree that forms dense cover, excluding all other species, and prevents the reestablishment of native lowland forest plants. The large, black fruit is dispersed by frugivorous birds and feral pigs (PIER 2008k). This species occurs in mesic valleys and disturbed mesic forest habitats (Wagner

et al.

1999, p. 168).

•

Syzygium jambos

has fruit that are dispersed by birds as well as by humans, and possibly by pigs. This tree is detrimental to native ecosystems because it does not need disturbance to become established, and can germinate and thrive in shade, eventually overtopping and replacing native canopy trees (U.S. Army 2006, p. 2-1-23). This species occurs in low-elevation, mesic to wet sites, primarily valleys and occasionally in disturbed, mesic forest habitats (Wagner

et al.

1999, p. 975).

•

Tecoma stans

is a shrub or small tree that can form dense stands that inhibit regeneration of native species. Its seeds are wind-dispersed (PIER 2008l). This species occurs in dry to mesic habitats (Wagner

et al.

1999, p. 389).

•

Toona ciliata

is a fast-growing tree with wind-dispersed seeds and an open, spreading crown that overtops and displaces native forest (Wagner

et al.

1999, p. 920; Koala Native Plants 2005). This species occurs in disturbed mesic to wet habitats (Wagner

et al.

1999, p. 168).

•

Urochloa mutica

is a fast growing, perennial grass native to Africa. It is considered an aggressive invasive weed of marshes and wetlands, forming dense monotypic stands that eliminate any open water by layering of its trailing stems (Smith 1985, p. 186; Erickson and Puttock 2006, p. 270). The species also forms monotypic stands in forest openings, displacing native plants. This species has been documented in riparian habitats, freshwater wetlands, swamps, and disturbed sites (

http://www.fs.fed.us/database/feis/plants/graminoid/uromut/all.html

).

•

Verbesina encelioides,

a tap-rooted, annual herb native to Mexico and the southwestern United States, is naturalized in Hawaii (Wagner

et al.

1999, p. 372). This plant has a number of aggressive characteristics that allow it to outcompete native plants, including tolerance of a wide range of growing conditions, rapid growth, allelopathic effects on other plants, high seed production, and dispersal with high germination rates. In addition, it is poisonous to livestock (Shluker 2002, pp. 3-4, 7-8).

Verbesina

has become a widespread and aggressive weed on both Midway Atoll and Kure Atoll, where it interferes with seabird nesting and inhibits native plant growth (Shluker 2002, pp. 3-4, 8). This species has been documented at several localities on Oahu, and occurs in dry and disturbed habitats (Wagner

et al.

1999, p. 168).

Habitat Destruction and Modification by Fire

Fire is a relatively new, human-exacerbated threat to native species and natural vegetation in Hawaii. The historical fire regime in Hawaii was characterized by infrequent, low-severity fires, as few natural ignition sources existed (Cuddihy and Stone 1990, p. 91; Smith and Tunison 1992, pp. 395-397). Natural fuel beds were often discontinuous, and rainfall in many areas on most islands was, and is moderate to high. Fires inadvertently or intentionally ignited by the original Polynesians in Hawaii probably contributed to the initial decline of native vegetation in the drier plains and foothills. These early settlers practiced slash-and-burn agriculture that created open lowland areas suitable for the later colonization of nonnative, fire-adapted grasses (Kirch 1982, pp. 5-6, 8; Cuddihy and Stone 1990, pp. 30-31). Beginning in the late 18th century, Europeans and Americans introduced plants and animals that further degraded native Hawaiian ecosystems. Pasturage and ranching, in particular, created highly fire-prone areas of nonnative grasses and shrubs (D'Antonio and Vitousek 1992, p. 67). Although fires are infrequent in mountainous regions today, extensive fires have occurred in lowland mesic areas, leading to grass/fire cycles that convert woodland to grassland (D'Antonio and Vitousek 1992, p. 77).

Although Vogl (1969) (in Cuddihy and Stone 1990, p. 91) proposed that naturally occurring fires, primarily from lightning strikes, have been important in the development of the original Hawaiian flora, and that many Hawaiian plants might be fire adapted, Mueller-Dombois (1981), in Cuddihy and Stone (1990, p. 91), points out that most natural vegetation types of Hawaii would not carry fire before the introduction of alien grasses. Smith and Tunison (in Cuddihy and Stone 1990, p. 91) state that native plant fuels typically have low flammability. Because of the greater frequency, intensity, and duration of fires that have resulted from the introduction of nonnative plants (especially grasses), fires are now destructive to native Hawaiian ecosystems (Brown and Smith 2000, p. 172), and a single grass-fueled fire can kill most native trees and shrubs in the burned area (D'Antonio and Vitousek 1992, p. 74).

Fire represents a threat to six of the plant species proposed for listing in this proposed rule,

Bidens amplectens, Cyanea calycina, Doryopteris takeuchii, Korthalsella degeneri, Pleomele forbesii, and Pteralyxia macrocarpa

(see Table 2). These six plant species are found in the coastal, lowland dry, lowland mesic, or dry cliff ecosystems. Fire can destroy dormant seeds of the six species as well as the plants themselves, even in steep or inaccessible areas. Successive fires that burn farther and farther into native habitat destroy native plants and remove habitat for native species by altering microclimate conditions favorable to alien plants. Alien plant species most likely to be spread as a consequence of fire are those that produce a high fuel load, are adapted to survive and regenerate after fire, and establish rapidly in newly burned areas. Grasses (particularly those that produce mats of dry material or retain a mass of standing dead leaves) that invade native forests and shrublands provide fuels that allow fire to burn areas that would not otherwise easily burn (Fujioka and Fujii 1980, in Cuddihy and Stone 1990, p. 93; D'Antonio and Vitousek 1992, pp. 70, 73-74; Tunison

et al.

2002, p. 122). Native woody plants may recover from fire to some degree, but fire tips the competitive balance toward alien species (National Park Service 1989, in Cuddihy and Stone 1990, p. 93).

On a post-burn survey at Puuwaawaa on the island of Hawaii, within an area of native

Diospyros

forest with undergrowth of the nonnative grass

Pennisetum setaceum,

Takeuchi noted that “no regeneration of native canopy is occurring within the Puuwaawaa burn area” (Takeuchi 1991, p. 2). Takeuchi also stated that “burn events served to accelerate a decline process already in place, compressing into days a sequence which would ordinarily have taken decades” (Takeuchi 1991, p. 4), and concluded that in addition to increasing the number of fires, the nonnative

Pennisetum

acted to suppress establishment of native plants after a

fire (Takeuchi 1991, p. 6). There have been several recent fires on Oahu that have impacted rare or endangered species, including areas being proposed as critical habitat in this proposed rule. Between 2004 and 2005, wildfires burned more than 360 ac (146 ha) in Honouliuli Preserve, home to more than 90 rare and endangered plants and animals, which is located along the windward side of the Waianae Mountains (The Nature Conservancy, in litt. 2005). In 2006, a fire at Kaena Point State Park burned 60 ac (24 ha), including portions of two proposed critical habitat units, and encroached on endangered plants in Makua Military Training Area. In 2007, there was a significant fire at Kaukonahua that crossed 12 gulches, eventually encompassing 5,655 ac (2,289 ha), and negatively impacted seven endangered plant species. Occurrences of three of the species were extirpated as a result of the fire. The Kaukonahua fire also provided pathways for nonnative ungulates (cattle, goats, and pigs) into previously undisturbed areas, and opened up previously densely vegetated areas for growth of the invasive grass

Panicum maximum

(guinea grass), which is also used as a food source by cattle and goats. An area infested by guinea grass burned, and the grass was observed to generate blades over 2 feet in length only 2 weeks after the fire (U.S. Army Garrison 2007, Appendices pp. 1-5). In 2009, there were two smaller fires that burned 200 ac (81 ha) at Manini Pali (Kaena Point State Park) and 3.8 ac (1.5 ha) at Makua Cave (at the mouth of Makua Valley). Both of these fires burned in currently designated critical habitat, although no individual plants were directly affected (U.S. Army Natural Resource Program 2009, Appendix 2, 17 pp.). These examples of recent fires illustrate that nonnative grass invasion leads to grass/fire cycles that convert native vegetation to grassland (D'Antonia and Vitousek 1992, p. 77).

Habitat Destruction and Modification by Hurricanes

Hurricanes adversely impact native Hawaiian terrestrial habitat, including each of the seven Oahu ecosystems and their associated species identified in this proposed rule. They do this by destroying native vegetation, opening the canopy and thus modifying the availability of light, and creating disturbed areas conducive to invasion by nonnative pest species (see “

Specific Nonnative Plant Species Impacts,”

above) (Asner and Goldstein 1997, p. 148; Harrington

et al.

1997, pp. 539-540). Canopy gaps allow for the establishment of nonnative plant species, which may be present as plants, or as seeds incapable of growing under shaded conditions. In addition, hurricanes adversely impact native Hawaiian stream habitat by defoliating and toppling vegetation, thus loosening the soil around the toppled vegetation. Loosened soil, loose vegetation, and other debris can be washed into streambeds (by hurricane-induced rain or subsequent rain storms), resulting in the scouring of the stream bottoms and channels, and catastrophic flooding (Polhemus 1993, 88 pp.). Because many Hawaiian plant and animal species, including the 23 species proposed for listing as endangered in this proposed rule, persist in low numbers and in restricted ranges, natural disasters, such as hurricanes, can be particularly devastating (Mitchell

et al.

2005, p. 4-3).

Hurricanes affecting Hawaii were only rarely reported from ships in the area from the 1800s until 1949. Between 1950 and 1997, 22 hurricanes passed near or over the Hawaiian Islands, 5 of which caused serious damage (Businger 1998, pp. 1-2). In November 1982, Hurricane Iwa struck the Hawaiian Islands, with wind gusts exceeding 100 miles per hour (mph) (161 kilometers per hour (kph)), causing extensive damage, especially on the islands of Niihau, Kauai, and Oahu (Businger 1998, pp. 2, 6). Many forest trees were destroyed (Perlman 1992, pp. 1-9), which opened the canopy and facilitated the invasion of nonnative plants (Kitayama and Mueller-Dombois 1995, p. 671). Competition with nonnative plants is a threat to each of the 7 ecosystems and the 20 plant species addressed in this proposed rule, as described in the “

Specific Nonnative Plant Species Impacts”

section above. In September 1992, Hurricane Iniki, a category 4 hurricane with maximum sustained wind speeds recorded at 140 mph (225 kph), passed directly over the island of Kauai and close to the island of Oahu, causing significant damage to areas along Oahu's southwestern coast (Barber's Point or Kalaeloa, through Kaena Point) (Blake

et al.

2007, p. 20), where

Bidens amplectens

occurs. Biologists have documented hurricane damage (e.g., denuded foliage, toppled and uprooted trees and shrubs, landslides) to the habitat of six other plant species (

Cyrtandra kaulantha, C. sessilis, Melicope christophersenii, M. hiiakae, Platydesma cornuta

var.

cornuta,

and

Psychotria hexandra

ssp.

oahuensis

). Polhemus (1993, pp. 86-87) documented the extirpation of the scarlet Kauai damselfly (

Megalagrion vagabundum

), a species related to the blackline, crimson, and oceanic Hawaiian damselflies included in this listing proposal, from the entire Hanakapiai Stream system on the island of Kauai as a result of the impacts of Hurricane Iniki in 1992. Damage by future hurricanes could further decrease the remaining native-plant dominated habitat areas that support rare plants and animals in Oahu ecosystems (Bellingham

et al.

2005, p. 681).

Habitat Destruction and Modification Due to Landslides, Rockfalls, Flooding, and Drought

Landslides, rockfalls, and flooding destabilize substrates, damage and destroy individual plants, and alter hydrological patterns, which result in changes to native plant and animal communities. In the open sea near Hawaii, rainfall averages 25 to 30 in (630 to 760 mm) per year, yet the islands may receive up to 15 times this amount in some places, caused by orographic features (Wagner

et al.

1999; adapted from Price (1983) and Carlquist (1980), pp. 38-39). During storms, rain may fall at 3 in (76 mm) per hour or more, and sometimes may reach nearly 40 in (1,016 mm) in 24 hours, causing destructive flash-flooding in streams and narrow gulches (Wagner

et al.

1999; adapted from Price (1983) and Carlquist (1980)), pp. 38-39). Due to the steep topography of much of the area on Oahu where the species remain, erosion and disturbance caused by introduced ungulates exacerbate the potential for landslides, rockfalls, or flooding, which in turn threaten native plants and some of the damselfly species (see Table 2). For those species that occur in small numbers in highly restricted geographic areas, such events have the potential to eradicate all individuals of a population, or even all populations of a species, resulting in extinction.

Landslides and rockfalls likely adversely impact nine of the species addressed in this proposed rule, including

Cyanea lanceolata, Cyrtandra kaulantha, C. sessilis, Doryopteris takeuchii, Melicope makahae, Platydesma cornuta

var.

decurrens, Psychotria hexandra

ssp.

oahuensis,

and the crimson and oceanic Hawaiian damselflies, as documented in observations by field botanists and surveyors (HBMP 2008). Monitoring data from the PEP program and the Hawaii Biodiversity and Mapping Program (HBMP) suggest that these nine species are threatened by landslides or falling rocks, as they are found in landscape settings susceptible to these events (e.g., steep slopes and cliffs). Since

C. kaulantha

is known from only

a few individuals in steep-walled stream valleys, one landslide could lead to near extirpation of the species by direct destruction of the individual plants, mechanical damage to individual plants that could lead to their death, destabilization of the cliff habitat leading to additional landslides, and alteration of hydrological patterns (e.g., affecting the availability of soil moisture). Landslides can modify and destroy riparian and stream habitat by direct physical damage (e.g., rocks and debris falling in a stream, mechanical damage to riparian vegetation), and create disturbed areas leading to invasion by nonnative plants that outcompete the native plants, as well as damage or destroy plants used by the crimson and oceanic damselflies for perching. Field survey data presented by Bakutis (in litt. 2006c) and the PEP Program (2006, p. 51) suggest that flooding is a likely threat to two plant species included in this proposed listing, one population of

Psychotria hexandra

ssp.

oahuensis,

located in a narrow gulch, and one population of

Cyrtandra sessilis,

growing near a stream in a narrow valley. Intermittent flooding events likely occurred in the stream habitats of the blackline, crimson, and oceanic Hawaiian damselflies in the past, due to stochastic events such as storms and hurricanes. However, the current low numbers of individuals and populations, combined with their breeding, life history requirements in stream habitats, and reduced ranges of these three Hawaiian damselflies increase their vulunerability to the threat of flooding. The impact of flooding events may be increased by channelization of stream reaches, or degradation of riparian vegetation by feral ungulates. Naiads may be washed out of streams into the surrounding terrestrial habitat or washed downstream into portions of streams that are occupied by nonnative predatory fish. Adults perching on surrounding vegetation may be washed into flooded streams and drown.

The blackline, crimson, and oceanic Hawaiian damselflies may also be affected by temporary habitat loss associated with droughts, which are not uncommon in the Hawaiian Islands. Between 1860 and 2002, the island of Oahu was affected by 49 periods of drought (Giambelluca

et al.

1991, pp. 3-4; Hawaii Commission on Water Resource Management 2009a and 2009b). These drought events often desiccate streams, irrigation ditches, and reservoirs; deplete groundwater supplies; and lead to forest and brush fires (Hawaii Commission on Water Resource Management 2009a and 2009b). Desiccation of streams, ditches, and reservoirs directly removes damselfly hunting and breeding habitat. Drought leads to an increase in the number of forest and brush fires (Giambelluca

et al.

1991, p. v), causing a reduction of native plant cover and habitat (D'Antonio and Vitousek 1992, pp. 77-79), and of plants used by the three Hawaiian damselflies for perching and hunting for prey.

Habitat Destruction and Modification by Agriculture and Urban Development

Although we are unaware of any comprehensive, site-by-site assessment of wetland loss in Hawaii (Erikson and Puttock 2006, p. 40), Dahl (1990, p. 7) estimated that at least 12 percent of lowland to upper-elevation wetlands in Hawaii had been converted to non-wetland habitat by the 1980s. If only coastal plain (below 1,000 ft (305 m)) marshlands and wetlands are considered, it is estimated that 30 percent have been converted to agricultural and urban development (E. Kosaka, U.S. Fish and Wildlife Service, in litt. 1990). Historical records show these marshlands and wetlands provided habitat for many damselfly species, including the blackline, oceanic, and crimson Hawaiian damselflies (Polhemus 2007, pp. 233, 237-239; HBMP 2008).

Although filling of wetlands is regulated by permitting today, the loss of riparian or wetland habitats utilized by the blackline and crimson Hawaiian damselflies may still occur due to Oahu's population growth and development, with concurrent demands on limited developable land and water resources (Lester 2007). The State's Commission on Water Resource Management recognized the need for a water resource protection plan, which is currently under development (Commission on Water Resource Management 2010). In addition, marshes have been slowly filled and converted to meadow habitat as a result of sedimentation from increased storm water runoff from upslope development, the accumulation of uncontrolled growth of invasive vegetation, and blockage of downslope drainage (Wilson Okamoto & Associates, Inc. 1993, pp. 3-4, 3-5).

The threats posed by conversion of wetland and other aquatic habitat for agriculture and urban development are ongoing and are expected to continue into the future. Hawaii's population has increased almost 7 percent in the past 10 years, along with the associated increased demands on limited land and water resources (Hawaii Department of Business, Economic Development and Tourism 2010). These modified areas lack the aquatic habitat features that the blackline and crimson Hawaiian damselflies require for essential life-history needs, such as marshes, sidepools along streams, and slow sections of perennial streams, and no longer support populations of these two species. Agriculture and urban development have thus contributed to the present curtailment of the habitat of these two Hawaiian damselflies, and we have no indication that this threat is likely to be significantly ameliorated in the near future.

Habitat Destruction and Modification by Stream Diversion

Stream modifications began with the early Hawaiians who diverted water to irrigate taro (kalo,

Colocasia esculenta

). A taro planter's share of water was determined by the amount of labor contributed to the construction and maintenance of the ditch, and was not proportional to their acreage of flooded terraces. Water rights of others taking water from the main stream below the dam had to be respected, and no ditch was permitted to divert more than half the flow from a stream. Water was withdrawn according to a time schedule, from a few hours at a time day or night up to two or three days, and in times of drought, the “water boss” had the right to adjust the sharing of available water to meet exigencies (Handy and Handy 1972, pp. 58-59).

The advent of plantation sugarcane cultivation led to far more extensive stream diversions, with the first diversion built in 1856 on Kauai (Wilcox 1996, p. 54). The first diversion on Oahu, Oahu Ditch, was built in 1902 (Wilcox 1996, p. 65). These systems were designed to tap water at upper elevations (above 984 ft (300 m)) by means of a concrete weir in the stream (Wilcox 1996, p. 54). All, or most, of the low or average flow of the stream was, and often still is, diverted into fields or reservoirs, leaving many stream channels completely dry (Takasaki

et al.

1969, pp. 27-28; Harris

et al.

1993, p. 12; Wilcox 1996, p. 56).

By the 1930s, water diversions had been developed on all of the main Hawaiian Islands, and by 1978, the stream flow in more than half the 366 perennial streams in Hawaii had been altered in some manner (Brasher 2003, p. 1,055). Some stream diversion systems are extensive, such as the Waiahole Ditch on Oahu, built in the early 1900s, which diverts water from 37 streams within the ranges of the blackline, crimson, and oceanic damselflies, on the windward side of

Oahu to the dry plains on the leeward side of the island via a tunnel cut through the Koolau mountain range (Stearns and Vaksvik 1935, pp. 399-403; Tvedt and Oestigaard 2006, pp. 43-44). Historically, damselflies in the genus

Megalagrion

were a common component of Hawaiian streams and wetlands at elevations ranging from sea level to the summit of the Koolau Mountains on Oahu. This loss of stream habitat may have contributed to the extirpation of populations of the three damselflies from lower elevations in the Koolau range (Polhemus 2007, pp. 233-234, 238-239).

Habitat Destruction and Modification by Dewatering of Aquifers

In addition to the diversion of stream water and the resultant downstream dewatering, many streams on Oahu have experienced reduced or zero surface flow as a result of the dewatering of their source aquifers. Often these aquifers, which previously fed the streams, were tapped by tunneling or through the injudicious placement of wells (Gingerich and Oki 2000, p. 6; Stearns 1985, pp. 291-305). These groundwater sources were diverted for both domestic and agricultural use, and in some areas have completely depleted nearby stream and spring flows. For example, both the bore tunnels and the contour tunnel of the Waiahole Ditch system intersect perched aquifers (aquifers above the primary ground water table), which subsequently are drained to the elevation of the tunnels (Stearns and Vaksvik 1935, pp. 399-406). This has reduced stream habitat available to the blackline, crimson, and oceanic damselflies. Likewise, the boring of the Haiku tunnel on Oahu in 1940 caused a 25 percent reduction in the base flow of Kahaluu Stream, over 2.5 mi (4 km) away (Takasaki

et al.

1969, pp. 31-32), and has impacted available habitat for the blackline and oceanic Hawaiian damselflies (HBMP 2008). Many of these aquifers were also the sources of springs that contributed flow to Oahu's windward streams; draining of these aquifers caused many of the springs to dry up, including some over 0.3 mi (0.5 km) away from the bore tunnels (Stearns and Vaksvik 1935, pp. 379-380).

Habitat Destruction and Modification by Vertical Wells

Surface flow of streams has also been affected by vertical wells drilled in pre-modern times, because the basal aquifer (lowest groundwater layer) and alluvial caprock (sediment-deposited harder rock layer) through which the lower sections of streams flow can be penetrated and hydraulically connected by wells (Gingerich and Oki 2000, p. 6; Stearns 1940, p. 88). This allows water in aquifers normally feeding the stream to be diverted elsewhere underground. Dewatering of the streams by tunneling and well placement near or in streams was a significant cause of habitat loss, and these effects continue today. Historically, for example, there was sufficient surface flow in Makaha and Nanakuli Streams on Oahu to support taro loi (artificial ponds for taro cultivation) in their lower reaches, but this flow disappeared subsequent to construction of vertical wells upstream (B. Devick, State of Hawaii, pers. comm. 1995). The inadvertent dewatering of streams through the penetration of their aquifers (which are normally separated from adjacent waterbearing layers by an impermeable layer) by tunneling or through placement of vertical wells, caused the loss of blackline, crimson, and oceanic Hawaiian damselflies habitat, as these species were historically known from these areas.

Habitat Destruction and Modification by Stream Channelization

Stream degradation has been particularly severe on the island of Oahu where, by 1978, 58 percent of the perennial streams and banks had been channelized (e.g., concrete lined, partially lined, or altered) to control flooding (Polhemus and Asquith 1996, p. 24; Brasher 2003, p. 1,055). These alterations have resulted in an overall 89 percent loss of the total stream length island-wide (Polhemus and Asquith 1996, p. 24; Parrish

et al.

1984, p. 83). The channelization of streams creates artificial, wide-bottomed stream beds and often results in removal of riparian vegetation, which reduces shading, increases substrate homogeneity, increases temporal water velocity (increased water flow speed during times of higher precipitation including minor and major flooding), and causes higher water temperatures (Parrish

et al.

1984, p. 83; Brasher 2003, p. 1,052). Tests conducted on native aquatic species showed that the higher water temperatures in channelized streams caused stress, and sometimes death (Parrish

et al.

1984, p. 83). Natural streams meander and are lined with rocks, trees, and natural debris, and during times of flooding, jump their banks. Channelized streams are straightened and often lack natural obstructions, and during times of higher precipitation or flooding, facilitate a higher water flow velocity. Hawaiian damselflies are largely absent from channelized portions of streams (Polhemus and Asquith 1996, p. 24), which has likely contributed to a reduction in the historic range of Hawaiian damselfly species. In contrast, undisturbed Hawaiian stream systems exhibit a greater amount of riffle and pool habitat canopy closure, higher consistent flow velocity, and lower water temperatures that are characteristic of streams to which the Hawaiian damselflies, in general, are adapted (Brasher 2003, pp. 1,054-1,057).

Channelization of streams has not been restricted to lower stream reaches. For example, there is extensive channelization of Oahu's Kalihi Stream above 1,000 ft (300 m) elevation. Extensive stream channelization on Oahu has also contributed to the loss of habitat for the blackline, crimson, and oceanic Hawaiian damselflies (Englund 1999, p. 236; D. Polhemus, in litt. 2008).

Stream diversion, channelization, dewatering, and vertical wells represent serious and ongoing threats to the blackline, crimson, and oceanic Hawaiian damselflies for the following reasons: (1) They reduce the amount and distribution of stream habitat available to these species; (2) they reduce stream flow, leaving lower elevation stream segments completely dry except during storms, or leaving many streams completely dry year round, thus reducing or eliminating stream habitat; and (3) they indirectly lead to an increase in water temperature that results in physiological stress and to the loss of blackline, crimson, and oceanic Hawaiian damselfly naiads. The blackline, crimson, and oceanic Hawaiian damselflies are particularly vulnerable to extinction due to such changes (i.e., stream diversion, channelization, and dewatering), which is exacerbated by their range and habitat constrictions and declines in their population numbers.

Habitat Destruction and Modification by Climate Change

Climate change will be a particular challenge for biodiversity because the introduction and interaction of additional stressors may push species beyond their ability to survive (Lovejoy

et al.

2005, pp. 325-326). The synergistic implications of climate change and habitat fragmentation are the most threatening facet of climate change for biodiversity (Lovejoy

et al.

2005, p. 4). The magnitude and intensity of the impacts of global climate change and increasing temperatures on native Hawaiian ecosystems are unknown. We are not aware of climate change studies specifically related to the seven Oahu ecosystems described in this proposed rule, or the 23 species proposed for

listing that are associated with those ecosystems. Based on the best available information, climate change impacts could lead to the loss of native species that comprise the communities in which the 23 species occur (Pounds

et al.

1999, p. 611-612; Still

et al.

1999, p. 610; Benning

et al.

2002, pp. 14,246 and 14,248). In addition, weather regime changes (e.g., droughts, floods) will likely result from increased annual average temperatures related to more frequent El Niño episodes in Hawaii. These changes may decrease water availability and increase the consumptive demand on Oahu's natural streams and reservoirs by Oahu's residents (Giambelluca

et al.

1991, p. v). The effects of increasing temperatures on the aquatic habitat of the three damselfly species are not specifically known, but likely include the loss of aquatic habitat from reduced stream flow, evaporation of standing water, and increased water temperature (Pounds

et al.

1999, pp. 611-612; Still

et al.

1999, p. 610; Benning

et al.

2002, pp. 14,246 and 14,248).

Oki (2004, p. 4) has noted long-term evidence of decreased precipitation and stream flow on the Hawaiian Islands, based upon evidence collected by stream gauging stations. This long-term drying trend, coupled with existing ditch diversions and periodic El Niño-caused drying events, has created a pattern of severe and persistent stream dewatering events (D. Polhemus, in litt 2008, p. 26). Future changes in precipitation and the forecast of those changes are highly uncertain because they depend, in part, on how the El Niño-La Niña weather cycle (a disruption of the ocean atmospheric system in the tropical Pacific having important global consequences for weather and climate) might change (Hawaii Climate Change Action Plan 1998, pp. 2-10).

The 23 species proposed for listing may be especially vulnerable to extinction due to anticipated environmental changes that may result from global climate change. Environmental changes that may affect these species are expected to include habitat loss or alteration and changes in disturbance regimes (e.g., storms and hurricanes), in addition to direct physiological stress caused by increased streamwater temperatures to which the native Hawaiian damselfly fauna are not adapted. The probability of a species going extinct as a result of these factors increases when its range is restricted, habitat decreases, and population numbers decline (Intergovernmental Panel on Climate Change 2007, p. 8). The 23 species have limited environmental tolerances, limited ranges, restricted habitat requirements, small population sizes, and low numbers of individuals. Therefore, we would expect these species to be particularly vulnerable to projected environmental impacts that may result from changes in climate, and subsequent impacts to their habitats (e.g., Pounds

et al.

1999, pp. 611-612; Still

et al.

1999, p. 610; Benning

et al.

2002, pp. 14,246 and 14,248). We believe changes in environmental conditions that may result from climate change may impact these 23 species, and we do not anticipate a reduction in this potential threat in the near future.

Summary of Habitat Destruction and Modification

The threats to the habitats of each of the 23 Oahu species addressed in this proposed rule are occurring throughout the entire range of each of the species. These threats include introduced ungulates, nonnative plants, fire, natural disasters, and climate change. In addition, the blackline, crimson, and oceanic Hawaiian damselflies are also threatened by agricultural and urban development, stream diversion, stream channelization, and stream dewatering.

The effects from ungulates are ongoing because ungulates currently occur in six of the seven ecosystems on which these species depend. The threat posed by introduced ungulates to the species proposed for listing that occur in these six ecosystems (see Table 2) is serious because they cause: (1) Trampling and grazing that directly impact the plant communities, which include the plant species proposed for listing, and impact plants in riparian areas used by the blackline, crimson, and oceanic damselflies for perching, reproduction, and hunting for prey; (2) increased soil disturbance, leading to mechanical damage to individuals of the plant species proposed for listing, and plants in riparian areas used by the damselflies for perching, reproduction, and hunting for prey; (3) creation of open, disturbed areas conducive to weedy plant invasion and establishment of alien plants from dispersed fruits and seeds, which results over time in the conversion of a community dominated by native vegetation to one dominated by nonnative vegetation (leading to all of the negative impacts associated with nonnative plants, listed below); and (4) increased watershed erosion and sedimentation, which affects aquatic habitats used by the three Hawaiian damselflies. Although plants used for perching by damselflies are not necessarily native plants, ungulate activity damages or removes all plants near the stream. Damselflies depend on plants near the stream for their daily activities, territory establishment, reproduction, and hunting prey. These threats are expected to continue or increase without ungulate control or eradication.

Nonnative plants represent a serious and ongoing threat to all 20 plant species being addressed in this proposed rule through habitat destruction and modification because they: (1) Adversely impact microhabitat by modifying the availability of light; (2) alter soil-water regimes; (3) modify nutrient cycling processes; (4) alter fire characteristics of native plant habitat, leading to incursions of fire-tolerant nonnative plant species into native habitat; and (5) outcompete and possibly directly inhibit the growth of, native plant species. Each of these threats can convert native-dominated plant communities to nonnative plant communities (Cuddihy and Stone 1990, p. 74; Vitousek 1992, pp. 33-35). This conversion has negative impacts on, and threatens, the 20 plant species addressed here.

The threat from fire to six species in this proposed rule (

Bidens amplectens, Cyanea calycina, Doryopteris takeuchii, Korthalsella degeneri, Pleomele forbesii,

and

Pteralyxia macrocarpa;

see Table 2) is a serious and ongoing threat because fire damages and destroys native vegetation, including dormant seeds, seedlings, and juvenile and adult plants. Many nonnative invasive plants, particularly fire-tolerant grasses, can outcompete native plants and inhibit their regeneration (D'Antonio and Vitousek 1992, pp. 70, 73-74; Tunison

et al.

2002, p. 122). Successive fires that burn farther and farther into native habitat destroy native plants and remove habitat for native species by altering microclimatic conditions and creating conditions favorable to alien plants. The threat from fire is unpredictable but omnipresent in ecosystems that have been invaded by nonnative, fire-prone grasses.

Natural disasters such as hurricanes represent a serious threat to 7 of the 20 plant species addressed in this proposed rule (

Bidens amplectens, Cyrtandra kaulantha, C. sessilis, Melicope christophersenii, M. hiiakae, Platydesma cornuta

var.

cornuta,

and

Psychotria hexandra

ssp.

oahuensis

), because they open the forest canopy, modify available light, and create disturbed areas that are conducive to invasion by nonnative pest plants (Asner and Goldstein 1997, p. 148; Harrington

et al.

1997, pp. 346-347). The discussion under “

Habitat Destruction and Modification by

Nonnative Plants

” above provides additional information related to canopy gaps, light availability, and the establishment of nonnative plant species. In addition, hurricanes threaten the three Hawaiian damselfly species in this proposed rule because they alter and cause direct damage to streams (Polhemus 1993, pp. 86-87). These impacts can be particularly devastating to the seven plant species and three Hawaiian damselfly species addressed in this proposed rule because due to other threats, they now persist in low numbers or occur in restricted ranges, and are therefore less resilient to such disturbances. Furthermore, a particularly destructive hurricane holds the potential of driving a localized endemic species to extinction in a single event. Hurricanes pose an ongoing and ever-present threat, because they can occur at any time, although their occurrence is not predictable.

Landslides, rockfalls, and flooding adversely impact ten of the species being proposed for listing (

Cyanea lanceolata, Cyrtandra kaulantha, C. sessilis, Doryopteris takeuchii, Melicope makahae, Platydesma cornuta

var.

decurrens, Psychotria hexandra

ssp.

oahuensis,

and the blackline, crimson and oceanic Hawaiian damselflies) (see Table 2), by destabilizing substrates, damaging and destroying individual plants and damselflies, and altering hydrological patterns. These threats result in habitat destruction or modification, and changes to native plant and animal communities. Drought threatens all three damselfly species being proposed for listing by dessication of streams, ditches, and reservoirs, which eliminates damselfly hunting and breeding habitat. These threats are significant and have the potential to occur at any time, although their incidence is not predictable.

The threats caused by conversion of wetland and other aquatic habitat to agriculture and urban development are ongoing, expected to continue into the future, and affect each of the damselflies proposed for listing in this proposed rule. Twelve percent of the freshwater habitat in Hawaii has already been lost, and 30 percent of all coastal plain wetlands in Hawaii have been lost to agriculture and urban development (E. Kosaka, in litt. 1990). These modified areas no longer support populations of these Hawaiian damselflies. These threats are expected to continue in the future.

Stream diversion, channelization, and dewatering represent serious and ongoing threats to the blackline, crimson, and oceanic Hawaiian damselflies because they: (1) Reduce the amount and distribution of stream habitat; (2) reduce stream flow, which leaves lower elevation stream segments either completely dry year round or completely dry except during storms, which reduces or eliminates stream habitat; and (3) indirectly lead to an increase in water temperature by altering the normal hydrograph patterns, which leads to the loss of damselfly naiads due to direct physiological stress. The probability of species extinction increases when ranges are restricted, the quality and quantity of habitat decreases, and population numbers decline. Accordingly, the blackline, crimson, and oceanic Hawaiian damselflies are vulnerable to extinction due to such changes in their stream habitat.

The projected effects of global climate change and increasing temperatures on the 23 species addressed in this proposed rule are related to changes in microclimatic conditions in their habitats. These changes may lead to the loss of native species due to direct physiological stress, the loss or alteration of habitat, increased competition from nonnative species, and changes in disturbance regimes (e.g., fire, storms and hurricanes). Because the specific and cumulative effects of climate change on these 23 species are presently unknown, we are not able to determine the magnitude of this possible threat with confidence.

B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

We are not aware of any threats to the 23 species addressed in this proposed rule that would be attributable to overutilization for commercial, recreational, scientific, or educational purposes.

C. Disease or Predation

Disease

We are not aware of any threats to the 23 species addressed in this proposed rule that would be attributable to disease.

Predation

Hawaii's plants and animals evolved in nearly complete isolation from continental influences. Successful colonization of these remote volcanic islands was infrequent, and many organisms never established populations. For example, Hawaii lacks any native ants or conifers, has very few bird families, and has only a single native land mammal (Loope 1998, p. 748). Defenses against mammalian herbivory, such as thorns, prickles, and production of toxins, were not needed, and the evolutionary pressure for plants to produce or maintain them was lacking. Therefore, Hawaiian plants either lost or never developed these defenses (Carlquist 1980, p. 173). The native flora and fauna of the islands are thus particularly vulnerable to the impacts of introduced nonnative species, as discussed below.

Introduced Ungulates

In addition to the habitat impacts discussed above, ungulates threaten the following 18 of the 20 plant species in this proposal by trampling and eating individual plants (this information is also presented in Table 2):

Bidens amplectens

(feral pigs and goats),

Cyanea calycina

(feral pigs and goats),

C. lanceolata

(feral pigs),

C. purpurellifolia

(feral pigs),

Cyrtandra gracilis

(feral pigs),

C. kaulantha

(feral pigs),

C. sessilis

(feral pigs),

C. waiolani

(feral pigs),

Melicope christophersenii

(feral pigs),

M. hiiakae

(feral pigs),

M. makahae

(feral pigs and goats),

Platydesma cornuta

var.

cornuta

(feral pigs),

P. cornuta

var.

decurrens

(feral pigs and goats),

Pleomele forbesii

(feral pigs and goats),

Psychotria hexandra

spp.

oahuensis

(feral pigs),

Pteralyxia macrocarpa

(feral pigs and goats),

Tetraplasandra lydgatei

(feral pigs), and

Zanthoxylum oahuense

(feral pigs). Predation by feral pigs and goats is also a threat to the host plants (

Nestegis sandwicensis

and

Sapindus oahuensis

) of

Korthalsella degeneri.

We have direct evidence of ungulate damage to some of these species, but for many, ungulate damage is presumed based on several studies conducted in Hawaii and elsewhere. In a study conducted by Diong (1982, p. 160) on Maui, feral pigs were observed browsing on young shoots, leaves, and fronds of a wide variety of plants, of which over 75 percent were endemic species (Diong 1982, p. 160). A stomach content analysis in this study showed that 60 percent of the pigs' food source consisted of the endemic

Cibotium

(hapuu, tree fern). Pigs were observed to fell plants and remove the bark of the native plant species

Clermontia, Cibotium,

Coprosma, Psychotria,

Scaevola,

and

Hedyotis,

resulting in larger trees being killed over a few months of repeated feeding (Diong 1982, p. 144). A study in Texas conducted by Beach (1997, pp. 3-4) revealed that feral pigs spread disease and parasites, and that their rooting and wallowing behavior led to spoilage of watering holes and loss of soil through leaching and erosion. Rooting activities also decreased the survivability of some plant species through disruption at root

level of mature plants and seedlings (Beach 1997, pp. 3-4).

Feral goats thrive on a variety of food plants, and are instrumental in the decline of native vegetation in many areas (Cuddihy and Stone 1990, p. 64). Feral goats trample roots and seedlings, cause erosion, and promote the invasion of alien plants. They are able to forage in extremely rugged terrain and have a high reproductive capacity (Clarke and Cuddihy 1980, p. C-20; van Riper and van Riper 1982, pp. 34-35; Tomich 1986, pp. 153-156; Cuddihy and Stone 1990, p. 64). A study of goat predation on a native

Acacia koa

forest on the island of Hawaii has shown that grazing pressure by goats can cause the eventual extinction of

Acacia koa

because it is unable to reproduce (Spatz and Mueller-Dombois 1973, p. 876). If goats are maintained at constantly high numbers, mature trees will eventually die, i

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