Kenai Beavers: Ecosystem Engineers

QUANTIFYING AND SUPPORTING KENAI BEAVERS AS A NATURE-BASED SOLUTION TO CLIMATE CHANGE

The Kenai peatlands

Alaska’s Kenai Peninsula is the eastern land mass containing Cook Inlet, the state’s most populated watershed in the Gulf of southcentral Alaska. In Kahtnuht’ana Dena’ina, the Kenai Peninsula is called Yaghanen, or the good land.

A portion of the Kenai Peninsula is considered peatlands. Peatlands are wetlands that accumulate layers of partially decayed organic matter, called peat, at their surface. Because they are constantly waterlogged, plant material doesn’t fully decompose.

The Kenai’s peatlands are a critical ecosystem, providing numerous benefits to both wildlife and humans. They moderate stream temperatures, help regulate flooding and moderate river flow, reduce erosion and sedimentation in the area’s rivers and streams, and stabilize groundwater flow. These actions have a direct effect on reducing flooding and mitigating wildfires.

The peatlands are also home to a wide range of flora and fauna, providing habitat for nearly 2,200 species, including caribou, migrating and resident passerines, brown and black bears, lynx, and wolves. Many peatland species are part of Alaskan Natives’ and others’ subsistence lifestyles, including berries, moose, and migratory birds. The peatlands also support anadromous streams where juvenile salmon are reared— these salmon grow up to become part of the region’s $84 million salmon fishery.

Peatlands like those on the Kenai are also incredible carbon sinks and are the largest natural terrestrial carbon store, storing more carbon than all other vegetation types in the world combined.  Conversely, damaged peatlands are a major source of greenhouse gas emissions, producing almost 5% of global CO2 emissions. Rewetting and restoring peatlands can reduce emissions significantly.  

Peatlands at risk

Unfortunately, peatlands on the Kenai Peninsula are at risk from the changing climate. A warmer, dryer climate combined with the lowering of groundwater levels due to isostatic rebound (the process by which land slowly rises after glaciers recede), is causing the Kenai peatlands to dry out. As they dry, critical habitat is lost, as well as the peatlands’ ability to function as a carbon sink.

Kenai’s peatlands span over 290,000 acres and have been drying at a rate of 6-11% of the surface area per decade since the 1950s. Since 1969, available water on the western portion of the Kenai Peninsula has decreased by 62%.  Climate change and the resulting drying of the landscape are transitioning peatlands to shrubby forests.

A major consequence of peatland drying is the increased fire risk; as 8,000-year-old peatlands dry out, they become fuel for fires, rather than natural firebreaks. Black spruce, a prominent encroaching tree species, is very fire-prone. The new fledging grasslands created by peatland drying are also unprecedented and have resulted in human-caused grassland wildfires in spring, followed by the first-ever lightning-caused grassland fires in the region.

There are also other consequences associated with peatland drying. Peatlands with a lower water table are less able to supply temperature-modulating groundwater or nutrients for salmon stream productivity. The peatlands that once held enormous amounts of carbon are rapidly transitioning to grasslands, which reduces habitat for moose, berries, and rearing fish.

Ultimately, loss of peatlands also results in widespread changes in the species composition, both plant and animal, of the area. 

Why are beavers important on the kenai?

Alaska Wildlife Alliance has contributed to the development of the Resist, Accept, Direct (RAD) framework, which lays out three choices for communities and agencies to guide their climate adaptation planning. RAD carves up the climate adaptation decision space into three action-oriented bins: Resist, Accept, and Direct.

Beavers fall under the Resist category, and are a nature-based solution for maintaining waterlogged peatlands in a changing climate. Their dams preserve wetlands, improve water quality, and reduce floods. By damming, beavers create habitat for salmon, trout, and moose. They also create wetlands, which help mitigate the risk of large-scale wildfires. This idea is supported by and exemplified in published work around North America, but novel in Alaska.

However, beavers in the Kenai Peninsula have been heavily trapped and hunted —leading to some regions being completely extirpated —and the current population is reduced to just 20% of its historical numbers.  We believe that if beavers can be recovered to their range, they may help “resist” climate change through their inherent wetland engineering.

What Is AWA Doing to support kenai beavers?

We’ve partnered with the Kachemak Bay National Estuarine Research Reserve, the University of Alaska Center for Conservation Science, and the University of South Florida to demonstrate that beavers and their dams can combat climate change. We’ll quantify the hydrologic impacts of beaver dams on peatlands and wetlands, educate the public and decision-makers on the value of beavers, explore systems for relocating problem beavers, and advocate for regulations that allow for trapping but also ensure sustainable beaver populations. As beaver populations on the Kenai Peninsula continue to decline due to trapping – and in some locations are completely extirpated, communicating their positive impact is important. The State’s low economic value for these peatlands makes them vulnerable to being sold and developed for economic benefits, and their ecological functions may be disrupted. Understanding the ecosystem value of these peatlands and the role of beavers is essential to saving them.

Since 2023, we have monitored three demonstration sites on the Kenai to test beavers as a nature-based solution to protecting Kenai’s peatlands. This summer, we repaired a previously breached beaver dam, created a beaver dam analog (BDA), and observed a control site. At each site, we are monitoring the zone of influence that beaver dams have on water temperature, flow, carbon storage, and habitat.

Our research is supported by a grant award made by the Wildlife Conservation Society through its Climate Adaptation Fund, which was established by a grant from the Doris Duke Charitable Foundation. We are also honored to have received support from the Martha H. Briscoe Environmental Science and Conservation Fund at the Homer Foundation.

Looking ahead and how you can help Kenai Beavers

In order to restore Kenai peatlands and communicate the importance of beavers, AWA and partners will work on the following objectives:

• Validating beavers as a nature-based solution to climate change through the rewetting and mitigating the drying of watersheds of southern Kenai by quantifying hydrological change of beaver dams and beaver dam analogs (man-made dams).

• Host site-visits and communicate the value of beavers on the ecosystem to land and wildlife managers, municipal planning authorities, private landowners, Tribes, and others.

• Quantify carbon storage by the region’s peatlands.

• Develop an interagency beaver working group to find opportunities for coexistence interventions so “problem beavers” may be relocated, instead of killed, to peatlands in need.  

• Advocate for restrictions on beaver trapping and greater protections for beavers.

• Create a communication plan which includes blogs, radio programs, and social media posts, to share the value of beavers to Kenai residents.

We hope to raise $500,000 by 2027 for our Kenai Beavers project. To help support our work, please donate to Alaska Wildlife Alliance. If you live on the Kenai and are interested in potential volunteer opportunities or events related to this project, please send us an email.