Invasive Plant Management Plan (2026)

Invasive Plant Management Plan

Sitka Tribe of Alaska

February 18, 2026

Kayaaní Commission & Resource Protection Department

Prepared by Sienna Reid, Kayaaní Commission Coordinator

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STA Invasive Plant Management Plan

Acknowledgements

Atlein Gunalchéesh

This project would not have been successful without the assistance of Sitka Tribe of Alaska’s

Kayaaní Commission and Resource Protection Department, funding from the U.S. Department

of Agriculture, and technical support from the U.S. Forest Service Alaska Region, including the

State, Private, and Tribal Forestry branch, the Tongass National Forest, and the Sitka Ranger

District. Many others contributed to the creation of this Invasive Plant Management Plan

directly and indirectly. Special thanks to Southeast Alaska Watershed Coalition, Alaska

Department of Transportation and Public Facilities, Alaska State Parks, City & Borough of Sitka

Public Works Department, Sitka Trail Works, Sitka Conservation Society, Sitka Sound Science

Center, Sitka School District, and Mt. Edgecumbe High School.

Funding

This project was funded by the USDA Southeast Sustainability Strategy.

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STA Invasive Plant Management Plan

Contents

Introduction.................................................................................................................................................. 4

Purpose ......................................................................................................................................................... 5

Inventory ...................................................................................................................................................... 5

Data Review to Establish a Baseline......................................................................................................... 6

Identifying Priority Species....................................................................................................................... 6

Itadori ................................................................................................................................................... 7

Roadside Inventory and Infestation Mapping ......................................................................................... 8

Prevention through Outreach and Education............................................................................................. 11

Education and Community Outreach ..................................................................................................... 12

Collaborative Planning with Partners..................................................................................................... 14

Reporting New Infestations ................................................................................................................... 15

Eradication and Control .............................................................................................................................. 16

Biological ................................................................................................................................................ 16

Mechanical.............................................................................................................................................. 17

Chemical ................................................................................................................................................. 18

Conclusion .................................................................................................................................................. 19

References................................................................................................................................................... 21

Appendix A: Priority Invasive Plant Species for Inventory and Control Efforts ......................................... 22

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STA Invasive Plant Management Plan

Introduction

Sitka Tribe of Alaska (STA) is the federally recognized tribal government for Sheet’ká (Sitka,

Alaska) with over 4,881 Tribal citizens. As a tribal government, STA is responsible for the

health, safety, welfare, and cultural preservation of its tribal citizens.

Figure 1. Map of Sitka Tribe of Alaska’s Customary and Traditional Use Area.

Sitka Tribe of Alaska’s jurisdiction includes “all lands constituting the Native Village of Sitka

and the areas formerly known as ‘Indian Possessions’ and ‘Cottage Settlement’, and to all

surrounding areas of Indian Country, if any, including all customary and traditional use and

access areas in the vicinity of Baranof Island, Chichagof and surrounding islands, and all fee

lands and allotments and lands owned by Sealaska, Inc. or Shee-Atika, Inc. located therein (the

Native corporations established pursuant to the Alaska Native Claims Settlement Act (Pub. L. 924

STA Invasive Plant Management Plan

203) as amended to hold the land and other benefits provided by Congress in partial

compensation for the extinguishment of the Tribe’s aboriginal land rights), to the fullest extent

permitted by federal and tribal law” (Sitka Tribe of Alaska 2021). See Figure 1. above for a map

of the Customary and Traditional Use Area (i.e. Traditional Territory).

STA’s Kayaaní Commission (Plants Commission), established in 1998, is a group of Tribal Elders

and experienced plant harvesters working together to protect the native plants of Sheet’ká

Kwáan Territory and to preserve Tlingit plant knowledge. Haa kayaaní (our plants) provide for

us in the form of foods, medicines, and materials for cultural arts, tools, and technologies. The

STA Invasive Plant Management Plan arose from concerns of Sitka Tribal citizens about the

presence of invasive plants on the Sitka road system, and their impacts on the local

environment and subsistence harvesting activities.

Purpose

The vibrant rainforests that were once described as “pristine” and “untouched” by Western

explorers have always been known to the Tlingit people as respectfully managed and tended-to

ecosystems. Tlingit people have been transporting distant plant materials for thousands of

years; we have oral histories of our ancestors bringing red cedar, potatoes, bamboo, and a

variety of other plants to Sheet’ká through travel and trade. However, through colonization,

urbanization, and global climate change, our resilient lands and waters have faced rapid change

with little time to adapt. As settlers from different regions of the world have made their way to

Sheet’ká, so have exotic plants. Some of these exotic plants exhibit traits that make them

excellent competitors against the native flora; these we call invasive plants.

Invasive plants are species that are non-native to a region and cause harm to the ecosystem, the

economy, and/or human health. They possess certain biological advantages that help them

dominate local habitats and can be difficult to control once a population is established. Invasive

plants, at one time limited to their native ranges, now spread more easily in a globalized world.

Ports and terminals where boats, ships, and planes arrive in Southeast Alaska’s isolated island

communities are typically hotspots for new invasive species, as are roadside corridors where

ornamental garden escapees make their first jump into the wild.

The Sitka Tribe of Alaska’s Kayaaní Commission is tasked with protecting native plants and

their traditional teachings. Invasive plants have become a greater threat to native flora over the

past several years as tribal citizens have noticed them displacing local subsistence species. To

track and control these invasive species in Sheet’ká, STA’s Kayaaní Commission and Resource

Protection Department have developed an Invasive Plant Management Plan with support from

the U.S. Forest Service and many regional and community partners. This plan outlines the role

of Sitka Tribe in continuing to defend our Traditional Territory against invasive plants through

inventory, prevention, and control measures.

Inventory

As settlers moved to Sitka, they brought exotic garden ornamentals and stowaway seeds and

weeds which increased Sitka’s non-native plant populations. The goal of inventory work in Sitka

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STA Invasive Plant Management Plan

is to document which invasive plants are present in Sitka, where they are found, and the

qualities of their infestations.

Data Review to Establish a Baseline

Sitka’s invasive species monitoring has been sporadic with inventories being carried out by

several different agencies and organizations, each with varying survey areas, methods, and

goals. Staff at STA compiled and reviewed previous efforts to document invasive plants in Sitka

(Table 1.). These reports and maps created a starting point for staff to target specific species and

their locations.

Date

2004

2004-2012

2007

2014

2022

Invasive Plant Work

Final Report on Invasive Plants in Southeast Alaska

Exotic plant inventories, removal, and control within

the Sitka National Historical Park

Non-Native Plant Inventory of the Sitka/Hoonah Area

Invasive Plants Management Plan for Sitka

(Unpublished)

Jozef Slowik Knotweed Inventory

Agency or Organization

Sitka Conservation Society

National Park Service

USDA Forest Service

Southeast Soil & Water

Conservation District; USDA

Forest Service

UAF Cooperative Extension

Service

Table 1. Details of known invasive plant projects in Sitka, Alaska, 2004-present.

Platforms such as iNaturalist are also utilized in reviewing Sitka’s invasive plant infestations.

iNaturalist is an online platform which allows users to act as citizen scientists and upload

observations of plants, fungi, and animals. An iNaturalist project called “Introduced Plant

Species of Alaska” automatically gathers observations of non-native plant species within the

state, which facilitates locating invasive plants.

Additionally, University of Alaska Anchorage’s Alaska Center for Conservation Science (ACCS)

hosts a statewide database for invasive plants called the Alaska Exotic Plants Information

Clearinghouse (AKEPIC). This database stores invasive plant data from partner agencies and

organizations within an interactive ArcGIS map. ACCS has also developed an invasive plant

ranking system specific to Alaska which considers ecological impacts, biological characteristics,

and effort required to control or eradicate, among other factors.

By utilizing local invasive species reports, iNaturalist observations, the AKEPIC database, and

reports made by Tribal citizens and community members, STA staff developed a list of Sitka’s

known invasive plant species and their locations to inform inventory work.

Identifying Priority Species

Sitka Tribe of Alaska staff developed a ranked list of invasive plant species (see Appendix A) to

determine which species would be prioritized in initial inventory field work. Invasive plants that

had been documented in the Sitka area by the time of plan development were included on the

list. Priority species were determined by considering each species’ prevalence on the Sitka road

system, impact on ecology and subsistence, and AKEPIC invasiveness rankings.

Invasive plants designated as high priority are those recommended for immediate

documentation and monitoring, community education and prevention efforts, treatment plan

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developments, and control or removal efforts. Lower priority invasive plants are those with

lower AKEPIC invasiveness rankings and comparatively less impact on local plants and

ecosystems. Some of these lower priority weeds have a high prevalence in Sitka (i.e. Ranunculus

spp., Taraxacum spp., Digitalis purpurea, etc. are effectively naturalized), yet their environmental

and tribal impact are minimal.

Through the review and ranking of Sitka’s invasive plants, STA staff identified Itadori as the

highest-priority exotic plant in Sitka. According to AKEPIC’s non-native plant species list,

Itadori ranks 87 on the invasiveness scale from 0 to 100; an extremely high ranking, second only

to Myriophyllum spicatum (Eurasian watermilfoil) in Alaska. In fact, Itadori has been listed as

invasive or noxious in ten states (USDA Natural Resources Conservation Service, n.d.) and other

countries such as the United Kingdom.

Itadori

Itadori, or knotweed (Reynoutria japonica Houtt., synonyms Fallopia japonica, Polygonum

cuspidatum), is a perennial shrub native to East Asia which was first documented in Southeast

Alaska in 1981 (Alaska Center for Conservation Science 2024). The large, leafy plant can be

identified by its broad, spade-shaped leaves, its hollow, zigzagging reddish-brown stems and

twigs, and small white flowers. Itadori can grow up to 10 feet tall, forming dense thickets. Its

underground growth is similarly extensive, with thick rhizomes able to sprawl nearly 20 feet

(Klein 2011). In Alaska, Itadori primarily reproduces vegetatively from rhizomes, with small

fragments (as little as 700mg) able to produce new plants (Klein 2011).

The plant’s affinity for riparian, wetland, and disturbed roadside habitats has enabled it to

thrive in the Tongass, using a variety of competitive characteristics to displace native plants and

continue to spread. Rhizomes grow quickly, utilizing allelopathy (biochemicals released by an

organism) to slow and stop growth in surrounding vegetation and stems grow in high density

clusters forming monocultures. Furthermore, Itadori’s height makes it resistant to trampling,

and smaller plants are shaded by the tall, broad leaves in the growing season. In autumn, small

plants are smothered by falling leaf litter.

Tribal citizens, many of which rely on roadside berry patches for their summer harvesting, have

noted the impact of Itadori on native species such as anáanáx tléiḵw (salmonberry, Rubus

spectabilis), ch’eix’ (thimbleberry, Rubus parviflorus), and shaax (gray currant, Ribes bracteosum).

These berry species feed Tribal citizens as well as wildlife from birds and deer to bears. When

native plant populations cannot stand up to invasive plant infestations, the delicate balance in

our rainforest ecosystem is threatened. In addition to impacts on plants, Itadori’s tendency to

grow near freshwater sources has been known to degrade vital habitat for anadromous fish by

choking out streams and rivers (Figure 2) and damage infrastructure by breaking through

pavement and building foundations.

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STA Invasive Plant Management Plan

Figure 2. Invasive Reynoutria japonica encroaches on a culvert adjacent to Halibut Point Road in Sitka, Alaska.

Photo by Sienna Reid, STA (2024).

For the duration of STA’s Invasive Plant Management planning phase, staff have focused their

time on inventory, prevention, and control of invasive Itadori in Sitka. As a result, Itadori will

be highlighted as an example of current inventory, prevention, and eradication efforts in the

Invasive Plant Management Plan. The intention is that STA’s Itadori management work will

serve as a framework that can be adapted to include other high priority species (Appendix A) in

subsequent phases of the project.

Roadside Inventory and Infestation Mapping

The goal for the initial 2024 field season was to carry out invasive plant inventories across the

Sitka road system, focusing primarily on revisiting known infestations and identifying new sites

of high concern. STA staff were trained by project manager Joni Johnson (Invasive Plant and

Pesticide Use Coordinator with Forest Health Protection; State, Private, and Tribal Forestry, U.S.

Forest Service) in USFS invasive plant inventory techniques.

Together, USFS and STA surveyed sections of town important to Tribal citizens, including

accessible subsistence harvest spots, critical ecological habitats, residential areas, and cultural

sites along roads and trails. The inventory spanned a large portion of Sitka’s main highways

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(Halibut Point Road and Sawmill Creek Road), transportation hubs (ferry terminal and airport),

industrial zones, and core downtown area. Many previously recorded sites were ground-truthed

and updated to include more detailed information, and new sites were logged (Figure 3). Data

collected from the infestations is described in Table 2.

Data Type

Date and time

Plant species, using USDA plant symbol

Infestation ID

Polygon shape󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼

Percent coverage

Count

Distribution

Priority

Notes

Photo

Description

Date and time of observation are crucial for tracking

changes over time.

Species are identified by USDA Plant Symbol (e.g.

Polygonum cuspidatum = POCU6), making records

compatible with USFS database.

Individual infestations are given IDs for tracking over time.

If the site has been previously mapped by a partner

organization, STA collects data under the original

infestation ID and notes that the site is a revisit.

e.g. STA-POCU6-025 refers to STA’s 25th Polygonum

cuspidatum observation.

Through the Field Maps app, observers can plot the

perimeter of each infestation by manually placing points to

create a polygon, or by livestreaming their location as they

walk around the infestation. Polygons help track changes in

the severity of each infestation over time.

Percent coverage refers to the percent coverage of the

invasive plant within the plotted polygon. This value can

range from 0 to 100, depending on the plant’s spread and

presence or absence of other species.

Count refers to the number of invasive individuals within

the larger infestation. This can be determined by counting

individual stems, estimating, or describing as “too many to

count.”

The infestation’s distribution can be described as

grouped/clumped, linear, even, or variable.

Priority rankings (low, medium, high, very high) are

decided by the observer and informed by factors such as

invasiveness ranking, impacts (current and potential), and

perceived difficulty in control and/or eradication efforts.

The observer may make notes on the infestation, including

impacts to surrounding vegetation, habitat, subsistence

users, and infrastructure; landowner; and control

strategies.

Photos linked with each observation can aid land managers

in identifying the site and tracking changes over time.

Table 2. Descriptions of invasive plant field data collected to the USFS Invasive Species Mobile group.

STA staff recorded inventory data through the ArcGIS Field Maps app which was regularly

synced to the USFS Invasive Species Mobile (ISM) group hosted on ArcGIS Online. ISM compiles

USFS and partner invasive species records into a single nationwide map. USFS Alaska Region

staff periodically sync their records to AKEPIC for public viewing. New ISM records from the

2024 season, as well as older documented infestations in Sitka, were made available to STA.

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STA Invasive Plant Management Plan

Using the ArcGIS Online interface provided by the National Tribal Geographic Information

Support Center (Tribal GIS®), STA staff have developed internal maps for STA records.

Figure 3. 2024 Invasive Knotweed Inventory Map displaying new and revisited Reynoutria japonica sites on the

Sitka road system. Map prepared by Sienna Reid, STA (2025).

Points on the online maps are linked with the field data gathered throughout the inventory

process. In 2026 and onward, STA staff will maintain internal invasive plant maps, including the

invasive knotweed map, as a resource for the community, share maps and inventory findings

with collaborators and the community, and continue to grow mapping capabilities and data

sovereignty by developing an STA-owned field data collection application.

Inventory Goal 1: Maintain up-to-date invasive plant inventory maps

Timeframe: Annual

Actions:

• Revisit known high-priority plant infestations to document status (spread or control

successes)

• Expand on-the-ground documentation by conducting roadside invasive plant inventories

on previously unmapped roads

• Pull new infestations from public data sources mentioned above

• Recruit community partners and/or the public to cover more areas and species

Inventory Goal 2: Develop STA-owned data collection application for data sovereignty

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Timeframe: ~1 year

Actions:

• STA staff request technical assistance from partners (Tribal GIS, USFS, Southeast Alaska

Watershed Coalition, etc.) in creation of a Field Maps app for data collection

• STA project staff train additional STA staff and partners in data collection techniques to

increase mapping capacity

Prevention through Outreach and Education

As stated in our project narrative, one of the main goals of the Invasive Plant Management Plan

is to increase public awareness of invasive plants. Early intervention can make a world of

difference when it comes to preventing the spread of invasive species. The longer invasive plants

go untreated, the more extreme the eradication measures become.

Figure 4. Stages of Biological Invasion & Levels of Control. Graphic by Jacqueline Foss, USFS (2025).

Staff at Sitka Tribe of Alaska developed outreach and education opportunities to increase

invasive plant awareness in Sitka. These materials and programs will continue to be used and

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developed to increase awareness and engagement and will be adapted to include priority species

(See Appendix A). Staff strengthened partnerships with land managers and local environmental

and recreation organizations, leading to collaborative and community-centered work and

resource sharing.

Education and Community Outreach

Sitka Tribe began initial invasive plant education efforts in spring 2024 with support from USFS

(Table 3). STA led Sitka High School’s Traditional Ecological Knowledge class through an activity

which explored the impacts of invasive plants on vegetation density and biodiversity. Each class

visit involved development of classroom plans and educational materials such as worksheets,

plant identification guides, presentations, and activity guides; they provide a starting point for

consistent collaboration with Sitka schools and the potential to evolve into annual STA

education projects such as Herring Camp and Clam Camp.

Date

School

Description

Spring 2024

Sitka High School

Staff led an activity exploring invasive plant impacts on

local vegetation, and relationships between density and

biodiversity with the SHS Traditional Ecological

Knowledge class.

Fall 2024

Blatchley Middle School

STA staff spent three days with the BMS Get Outside and

Forest Exploration classes, covering southeast Alaska

ecology, native and invasive plant identi󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼

invasive plant prevention and control methods.

Spring 2025

Sitka High School

STA staff led SHS Biology students through an activity

exploring invasive plant impacts on local ecosystems

and presented on STA’s 󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼

next steps.

Fall 2025

Mt. Edgecumbe High School

STA staff visited MEHS Biology and Environmental

Science classes to share their work in the Resource

Protection Department, including the importance of

native plants to people and place, and the impacts of

invasive species.

Fall 2025

Sitka High School

STA staff coordinated with local USFS staff and the

Alaska Department of Transportation and Public

Facilities to lead SHS Biology students through Sitka’s

󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼

state managed Right-of-Way (ROW). Students learned

about the effects of invasive species and participated in

the tarping of four knotweed infested sites.

Table 3. Descriptions of the invasive plant education efforts carried out in Sitka schools facilitated by STA staff.

In addition to youth education, broader community outreach was done in the form of

community events and shared online resources. In September 2024, STA staff co-hosted

“Invasive Plants of Sitka: A Community Information Session” in partnership with the U.S. Forest

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Service and the Southeast Alaska Watershed Coalition (SAWC). The purpose of the meeting was

to provide information on the Kayaaní Commission’s invasive plant project and discuss invasive

plant concerns in the community.

Following the presentation, attendees had a chance to ask questions and discuss invasive plant

needs in the community. Overwhelmingly, citizens Sitka want to help; many attendees voiced the

need to not only educate on invasive species but instruct on what people can do to aid control

efforts. One idea was for STA to develop treatment prescriptions for the infestations identified

in the field season and communicate them with the landowner/land manager of the sites.

Another idea was to create a publication or social media campaign teaching Sitkans how to

identify invasive plants, evaluate treatment options, and manage yard waste responsibly.

Figure 5. E. Reed, Regional Invasive Plant Coordinator at SAWC, presents the impacts of invasive knotweed at the

2024 Invasive Plants of Sitka talk. Photo by Sienna Reid.

Taking community feedback into account, staff have continued to provide invasive plant project

updates at monthly Kayaaní Commission meetings and share invasive plant identification

guides, treatment recommendations, and prevention measures through flyers, emails, website

and social media posts, and community events.

Outreach Goal 1: Keep Sitkans informed on STA’s invasive plant management work

Timeframe: Ongoing

Actions:

• Make inventory maps available to community and regional partners

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•

•

Present maps, field findings, and other invasive plant resources at community events

Maintain and expand relationships with Sitka teachers to continue youth education in

the classroom

Outreach Goal 2: Promote prevention of invasive species

Timeframe: Ongoing

Actions:

• Familiarize community members with highly invasive plant species (priority species list)

• Create and share PSAs and social media content regarding invasive plants management

on the individual level (e.g. plant ID guides, responsible handling of yard waste, etc.)

• Respond to invasive plant reports by advising Sitkans on invasive plant management,

assisting in treatment planning, and connecting them with invasive plant experts

Collaborative Planning with Partners

Another facet of outreach efforts includes work to strengthen partnerships with relevant

government agencies and local organizations. In March 2025 the Sitka Tribe of Alaska hosted a

Collaborative Knotweed Planning Meeting to bring land managers, outdoor maintenance

workers, and environmental and recreation organizations together to discuss and plan for the

control of invasive plants, especially invasive knotweed, in Sitka. Meeting attendees included

representatives on the federal (U.S. Forest Service), state (AK Department of Transportation and

Public Facilities, AK State Parks), and local (City & Borough of Sitka Public Works Department)

levels. Local organizations were represented by executive directors of both Sitka Trail Works

and Sitka Conservation Society.

STA staff made a presentation which shared background on the STA Kayaaní Commission, the

Invasive Plant Management Plan, field work findings, and an overview of eradication options.

USFS staff facilitated a guided round-table discussion covering topics such as prevention and

control of invasive plant species, inventory and outreach ideas, and promoting creative uses of

invasive plants in foods, medicines, and dyes. The group then shared community resources that

they could contribute from their respective agencies and organizations. Overall, there was a

strong interest in collaborating for effective invasive plant management, with the limited factors

being funding and staff capacity.

The meeting concluded with the formation of a list of action items to keep up the momentum.

Several of the items were completed within the year including:

•

•

•

•

•

Producing flyers and social media posts regarding plant ID, reporting resources, regional

contacts, etc.

Releasing a PSA detailing responsible yard waste disposal around the time of the annual

City-wide spring clean up

Collaborating with Sitka Trail Works on an Invasive Plant Hike as part of their summer

hike series

Connecting partners with Alaska Certified Applicator training opportunities (for use of

herbicide)

Continuing to lead invasive plant education in Sitka High School science classes

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STA Invasive Plant Management Plan

Action items from the Collaborative Knotweed Planning Meeting that have not been completed

at time of Plan completion, but should guide future project directions include:

•

•

•

Designing a variety of informational one-pagers tailored to different demographics (e.g.

contractors, gardeners, hikers, Tribal citizens), emphasizing the risks that invasive plants

pose to foods, lands, culture, and infrastructure

Assessing potential for formal management agreements through MOUs between

landowners or establishment of a Community Integrated Species Management Area

(CISMA)

Discussing opportunities for expanding focus to more invasive species

Collaborative Goal 1: Strengthen working group of community partners to address invasive plant

inventory, outreach, and control

Timeframe: ~1 year

Actions:

• Facilitate Planning Group meeting(s) to stay tuned into current goals and projects

• Share PSAs and social media content (Outreach Goal 2) directly with Planning Group

partners to expand the reach

• Invite Planning Group to cohost and participate in outreach events such as presentations

or panel discussions, to better address needs of the community

• Encourage, support, and assist in invasive plant control efforts on land managed by

Planning Group partners

• Publicize or expand reach by invitation to grow Planning Group, especially targeting

grounds-workers (currently underrepresented) such as contractors and property

maintenance staff

• Seek funding opportunities that can fund positions across partner organizations

Reporting New Infestations

One simple way for members of the community to get involved with STA’s invasive plant work is

by reporting invasive plants to the STA Kayaaní Commission Coordinator. Infestations of highpriority invasive plants or unfamiliar plants can be reported for identification, documentation,

and in some cases, treatment recommendations. Concerned citizens may reach out to the

Kayaaní Commission Coordinator. Reports should include the plant’s location (e.g. addresses,

landmarks, or GPS locations), impact, and photo(s). STA is especially interested in invasive plant

infestations that are impacting Tribal citizens and their customary and traditional resources.

Many of these reporting options are promoted within STA’s community outreach materials.

For invasive plant identification, reporting, advising, and questions in Sitka:

•

•

Sienna Reid, Kayaaní Commission Coordinator

Sitka Tribe of Alaska

sienna.reid@sitkatribe-nsn.gov; (907) 747-7111

Jacqueline Foss, Soil, Ecology, Botany Program Manager

Tongass National Forest, USDA Forest Service

jacqueline.foss@usda.gov; (907) 747-4246

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STA Invasive Plant Management Plan

Through the planning process, STA has partnered with many invasive plant experts across the

region to offer the most accurate and helpful information to those wanting to learn more about

invasive plants or perhaps seek help in controlling invasives on their property.

For invasive plant identification, reporting, advising, and questions in Southeast Alaska:

•

E.M. Reed, Regional Invasive Plant Coordinator

Southeast Alaska Watershed Coalition

reed@sawcak.org

For treatment and control on state, private, and Tribal lands (statewide):

•

Joni Johnson, Invasive Plant and Pesticide Use Coordinator

Forest Health Protection; State, Private, and Tribal Forestry

USDA Forest Service

joni.m.johnson@usda.gov; (907) 772-5884

For state lands (state-maintained highways, Alaska State Parks):

•

•

Tammy Davis, Invasive Species Program Coordinator

Alaska Department of Fish and Game

Alaska Invasive Species Hotline: 1-877-468-2748

Jess Parks, Statewide Environmental Analyst/Integrated Pest Management

Alaska Department of Transportation

Eradication and Control

As discussed in the prevention section above, as invasive plant infestations establish and spread,

control and removal interventions become more drastic. Each invasive plant species has

different physical characteristics and biological traits to survive and spread, and thus each

species will vary in the methods needed to eradicate them. In invasive species management,

there are three main types of control strategies: biological, mechanical, and chemical control. A

fourth category – cultural control – refers to prevention and mitigation tactics discussed in the

previous section.

During the roadside inventory process, STA staff were involved in treatment planning for

various invasive plant infestations. Treatment plans are recommendations to the landowner or

land manager on how to best eradicate or control invasive plants on their property. Treatments

must be made specific to each individual site and depend on the species present, how well

established the infestation is (how long it has been there), and the goals of the landowner and/or

manager. Additionally, many government landowners have regulations on types of control (such

as restrictions on herbicide application), further complicating management planning and

execution.

Biological

One factor that makes invasive species so difficult to remove is that they often have no natural

predators in the new habitat that they have colonized. Biological control refers to the use of

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natural enemies to suppress an invasive species population. A large risk of biological control is

that the introduced predator, parasite, or pathogen may become an invasive species itself

without ecological checks and balances. At this time, there are no biocontrol agents approved

for use on invasive plants in the state of Alaska (Graziano et al. 2019).

Mechanical

Mechanical control refers to the removal or control of invasive plants through physical means,

such as mowing, cutting, hand-pulling, digging, burning, and shading, among others.

Mechanical treatments are the preferred strategy of STA whenever possible and effective.

In October 2025, STA implemented a mechanical treatment on four Itadori infestations in

partnership with AK DOT&PF, USFS Sitka Ranger District and Sitka School District. The sites

were identified in roadside inventories, determined to be suitable candidates for control through

tarping, and approved for control by AK DOT&PF. The tarps were installed as part of Sitka High

School biology classes’ ecology unit, where students learned the impact of Itadori on their local

ecosystem and participated in the first known active control of invasive knotweed on the statemanaged road.

Figure 6: Students in Sitka High School’s biology class cover an invasive knotweed patch with a tarp along Sawmill

Creek Road. Photo by Naomi Paulson, STA (2025).

The first tarps laid on the ROW marked a huge success for collaborative management of our

shared resources. Students were encouraged to check on the tarps that they installed, which will

be in place for at least the next several growing seasons. Maintaining the tarps will be a

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community-effort, led by STA. Following the installation, the work was featured in a Daily Sitka

Sentinel article, further increasing community awareness, and STA social media posts.

Not all mechanical strategies are effective on all species, so it is critical to ensure that the

methods used will have the intended effect. For example, soil and habitat disturbance created

from mowing or digging up Itadori can inadvertently increase the size and density of the

infestations and spread rhizome fragments to uninfested areas. Therefore, these approaches are

not the preferred method of control and require high levels of caution and diligence. The

effectiveness of these methods are mixed and likely inappropriate on their own for large or wellestablished populations. However, tarping can be effective on small, less-established patches of

invasive knotweed if diligently maintained over multiple growing seasons (several years).

In future control efforts, STA hopes to continue strengthening its partnerships and community

involvement opportunities to grow capacity and area covered. Itadori will remain a priority

species until it is functionally eradicated; however, the Tribe also aims to target more of a

variety of invasive plants in coming years in response to Tribal citizen observations and

concerns.

Control Goal 1: Maintain and expand Itadori tarping control sites

Timeframe: Ongoing

Actions:

• Monitor and maintain tarp sites installed in 2025 through at least 2028

• Post informational signage at tarp sites about the project, including contact information

• Work with AK DOT&PF to install more Itadori tarp sites on the Sitka road system

• Expand tarping sites by

• Use tarp installation as a learning opportunity by involving youth, Planning Group

partners, Tribal citizens, and community members.

• Evaluate effectiveness of the initial four SMC Itadori tarp sites annually, and at the

three-year mark determine if tarping will continue

Control Goal 2: Explore mechanical control options for other high-priority invasive plants

Timeframe: ~1 year

Actions:

• Hold listening sessions or surveys to document impact of high-priority invasives on

Tribal citizens, community members, and culturally important resources

• Research and discuss the locations of high-priority invasive plant species in Sitka (e.g.

Phalaris arundinacea L., Impatiens glandulifera, Hieracium aurantiacum, etc.) and their

removal with Planning Group partners

Chemical

Chemical treatment of invasive plants with herbicides or other compounds is another common

control and eradication method. For infestations occurring on Right-of-Ways herbicides may

only be applied by certified applicators. In other cases, a supervising certified applicator must be

present for others to assist. There are currently no certified applicators in Sitka, which makes

chemical control unrealistic and unsustainable for management efforts at present. There has

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been some interest and initiative by partner agencies and organizations to obtain herbicide

applicator training and certification in the near future.

In chemical control, timing is a key factor. For Itadori, herbicides are most effective when

applied at the end of the growing season. As perennial plants die back in the fall, their energy

stores move from leaves, flowers, and stem back into the roots and rhizomes for winter.

Herbicides applied above ground at this stage get transported into the roots, injuring and/or

killing the plant. UAF Cooperative Extension Service, AK DOT&PF, and USFS Alaska Region

published Best Management Practices: Controlling The Spread of Invasive Plants During Road

Maintenance which describes the most effective herbicides and application methods (when

mechanical removal is not practical) for a variety of invasive plants found in Alaska.

Chemical treatment has not been and will not be implemented by STA due to concerns about the

impact on the surrounding environment; however, STA acknowledges that under severe

circumstances chemical control can be the most effective strategy for invasive plant removal. At

the core of STA’s management approach is a strong desire to protect native environments,

organisms, and tribal citizens’ access to our traditional lands and resources.

If community partners decide to move forward with chemical control of invasive plants, STA

will recommend and assist with implementing alternative methods (mechanical if possible). If all

other options have been exhausted and it is determined that chemical treatment will be the only

effective technique for invasive plant removal at a specific site, STA urges those implementing

the chemical treatment to move forward with extreme caution, carefully following all label

instructions. At minimum, we ask on behalf of our tribal citizens for full transparency about the

chemicals used, application methods, and plans to minimize impact on non-target species. It is

critical to present adequate notice and signage on-site of herbicide use to maintain a respectful

and safe relationship with the citizens of Sitka.

Conclusion

STA is interested in continuing to lead invasive plant inventory, prevention, and control work in

Sheet’ká. The active management of Itadori has been a powerful learning tool to develop STA’s

ability to manage invasive plants in Sitka. Perhaps the most valuable lesson learned in the

planning process is that management is not possible without the support and collaboration of

our many partners. STA will continue to maintain and grow these relationships for the

maximum benefit of our tribal citizens and the protection of our lands, waters, natural

resources, and cultural heritage for future generations.

A simple budget for one year of Invasive Plant Management Plan implementation is below:

Implementation Needs

Cost estimate (1 year):

Personnel

Kayaaní Commission Coordinator (25%) - wages

Kayaaní Commission Coordinator - fringe

Travel

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$20,059.95

$1,735.19

Conference attendance (e.g. Alaska Invasive Species

Workshop) for KCC and Commissioner

$2,500.00

Supplies

Office supplies

$500.00

Program supplies (󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼󹀼

$1,000.00

Indirect Costs

STA Indirect (49.06% for 2026)

$12,655.09

Grand Total

$38,450.23

While limited funding has been secured for implementation over the next five years (2026-2031),

it falls short of meeting project needs in terms of staff time and supply needs. STA staff and

Kayaaní Commission will continue to search for funding sources to support invasive plant work,

ensuring the Invasive Plant Management Plan may be implemented for years to come.

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References

Alaska Center for Conservation Science. 2024. “Alaska Exotic Plant Information Clearinghouse

Database.” University of Alaska Anchorage. https://akepic.accs.axds.co.

Borneman, Elizabeth. 2022. Climate Vulnerability Assessment and Adaptation Plan. Sitka Tribe of

Alaska.

Graziano, Gino, Steven Seefeldt, and Lydia Clayton. 2019. Best Management Practices: Controlling

the Spread of Invasive Plants during Road Maintenance. UAF Cooperative Extension Service;

Alaska Department of Transportation & Public Facilities; U.S. Forest Service Alaska Region.

https://www.uaf.edu/ces/publications/database/agriculture-livestock/best-managementpractices.php.

Klein, Helen. 2011. “Fallopia Japonica.” University of Alaska Anchorage, February 7.

http://aknhp.uaa.alaska.edu.

Lamb, Melinda, and Michael Shephard. 2007. A Snapshot of Spread: Locations of Invasive Plants in

Southeast Alaska. U.S. Forest Service.

Pohl, Catherine, and Koren Bosworth. 2008. Non-Native Plant Inventory of the Sitka/Hoonah Area:

Summary of 2007 Roadside Surveys on Baranof, Chichagof, and Kruzof Islands, SE Alaska. U.S.

Forest Service.

Rapp, Whitney. 2006. Exotic Plant Management in Sitka National Historical Park Sitka, Alaska

Summer 2006 Field Season Report. U.S. National Park Service.

Sitka Tribe of Alaska. 2021. Sitka Tribe of Alaska Constitution. https://sitkatribe.org/ourgovernment/governance-documents/.

Slowik, Jozef, Jasmine Shaw, and Gino Graziano. 2020. Assessment of Potential Knotweed

Biocontrol Sites in Southeast Alaska, 17-21 August 2020. UAF Cooperative Extension Service.

USDA Natural Resources Conservation Service. n.d. “Polygonum Cuspidatum Siebold & Zucc.”

PLANTS Database. Accessed December 22, 2025. https://plants.usda.gov/plantprofile/POCU6.

Valverde, Kimberly, and Brian Maupin. 2019. Invasive Plants Management Plan for Sitka

(Unpublished draft). Southeast Soil & Water Conservation District.

Wilson, Carl N. 1965. Grass Seeding for Erosion Control in Southeast Alaska. U.S. Forest Service.

Winter, Genelle. 2022. Noxious Weed and Invasive Species Management Plan, Environmental

Assessment on Annette Islands Reserve 2017-2022. Metlakatla Indian Community.

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Appendix A: Priority Invasive Plant Species for Inventory and Control Efforts

Species

AKEPIC Invasiveness

Ranking

Common Name

Native Lookalikes

red = 1st priority

yellow = 2nd priority

Impacted Ecosystem

Fallopia japonica

itadori, Japanese knotweed

87/100

moist habitats, waste areas,

roadsides, old homesites,

neglected gardens

Phalaris arundinacea L.

reed canary grass

83/100

streambanks, wet meadows

Impatiens glandulifera

ornamental jewelweed

82/100

western touch-me-not

(Impatiens noli-tangere)

Riparian zone, wetlands,

beach meadows, neglected

gardens

orange agoseris (Agoseris

aurantiaca)

sub-alpine, meadows,

rangelands, pastures, forest

borders, roadsides,

disturbed areas

Hieracium aurantiacum

orange hawkweed

79/100

Cirsium arvense

Canada thistle, creeping thistle

76/100

Vicia cracca

bird vetch

73/100

Sonchus arvensis

field sowthistle

73/100

roadsides, forest edges,

forest openings

giant vetch (Vicia gigantea),

American vetch (Vicia

americana), marsh pea

(Lathyrus palustris), beach

pea (Lathyrus japonicus),

alpine sweetvetch

(Hedysarum alpinum)

Taraxacum ceratophorum, T.

alaskanum, T.

kamtschaticum, T.

phymatocarpum, T.

trigonolobum

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roadsides, forest edges and

openings, thickets

roadsides, disturbed sites,

old home sites, coves and

beaches

Linaria vulgaris

yellow toadflax, butter and eggs

69/100

roadsides, waste places

Cytisus scoparius

Scotch broom, common broom

69/100

urban, roadsides

Geranium robertianum

herb Robert, Robert’s geranium

67/100

roadsides, yards

Leucanthemum vulgare

oxeye daisy

61/100

Tanacetum vulgare

common tansy

60/100

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roadsides, meadows,

clearcuts, disturbed sites

roadsides, ditches, streams,

beach meadows

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