Restoring “green glaciers” to improve water quality and climate resilience

Riparian meadows “slow, spread, and sink” the flow of water, which enables their important roles in supporting biodiversity, carbon storage, water resource management, and wildfire management. Indigenous peoples also value meadows for their provision of culturally important plants, animals, and practices. Over the last 150 years most meadows have been degraded due to human activity, impairing their ecological, cultural, and hydrological functions. Restoring riparian meadows can enhance the services and values they provide, and Forest Service researchers are tackling this need for meadow restoration as described below.

Lost Meadows Model

Human activities like road building, water diversion, and livestock grazing have sped up the flow of water through meadows, reduced its lateral spread, and altered water table depths. These effects dry out meadows and make them more habitable to forest trees which encroach, and can eventually completely cover, meadow areas. Typically, meadows are defined by their vegetation, but to find “lost meadows” for potential restoration, other indicators are needed to identify them. The Lost Meadows Model uses machine learning to identify locations that support hydrogeomorphic and climatic conditions similar to existing wet meadow habitats. The model developed for the Sierra Nevada identified three to eight times more potential meadowlands than currently exist making possible gains from restoring meadows more relevant to landscape-scale restoration planning. Researchers plan to expand the modeling effort to additional forests and tribal lands.

Process-Based Restoration

One approach for meadow restoration is called “process-based restoration”. Rather than using heavy machinery and hardened structures with manmade materials, process-based restoration techniques rely on the energy (of downstream water flow) and materials (e.g. wood, rocks, soils) within the stream and meadow area to encourage natural sediment deposition, rework water channels, reconnect floodplains to streams, and facilitate biological recovery. However, we lack scientific evidence about the efficacy of using these ecological restoration approaches for degraded meadows with deeply incised channels and altered flow paths. This project seeks to examine meadow recovery processes to provide needed information on the effectiveness of ecological restoration approaches under different landscape disturbance regimes and geological conditions.

Post-Fire Meadow Restoration

Wildland fires reduce vegetation and increase sedimentation in waterways, which can become problematic for downstream human-constructed reservoirs and water supplies. This research project will take advantage of post-fire conditions to test whether fire disturbance can heal degraded meadows with limited management intervention. The Sierra Nevada Project is a six-catchment meadow restoration experiment occurring in the Plumas NF and Sierra NF to document the efficacy of capturing fire-enhanced sediment pulses with process-based restoration approaches in degraded meadows. Goals include helping to determine priority locations for restoration to obtain faster, more effective, and lower cost restoration successes.

Enhancing Fish Habitat

The East Fork of the Scott river in the Klamath National Forest is an important Coho spawning and rearing stream. To provide enough cold water for quality salmon habitat, the Scott Watershed’s Integrated Fisheries Restoration and Monitoring program has identified mountain meadow restoration as a high priority. The Klamath Project restore two high value, mountain meadow stream catchments comprising 4,190 acres and 11.05 stream miles in the Upper East Fork Scott Watershed in the Klamath National Forest. Project goals are to 1) foster resiliency to drought and floods and reduce wildfire risk by rewetting wet meadow habitats and storing water longer in the headwaters, 2) connect people to the outdoors by working with the Quartz Valley Indian Reservation and the Scott River Watershed Council to engage a local workforce to implement the restoration and conduct monitoring, and 3) improve aquatic organism passage by upgrading failed culverts at road crossings and increasing stream baseflow, which is important for maintaining coho salmon in the lower watershed.
 

Objectives

The project aims to increase the coupled restoration of low gradient stream and meadow habitats with adjacent forest lands to:

1. Improve water quality by increasing lateral floodplain connectivity and groundwater filtration
2. Foster resiliency to drought and floods and reduce wildfire risk by rewetting wet meadow habitats and storing water longer in the headwaters
3. Create climate and wildfire refugia for wildlife by restoring cool, wet habitats that do not readily burn
4. Strengthen communities and connect people to the outdoors by working with local tribes and engaging a local workforce to implement restoration and conduct monitoring
5. Expand the scope of a machine learning model to identify “lost meadows” in western forests
6. Advance our knowledge about effective restoration techniques for providing abundant clean water to downstream users including tribes, ranchers, and aquatic biota. 

Expected Project Results

Outputs

• GIS-based maps of predicted high probability meadow habitats across three mountain ranges (Sierra Nevada, Klamath-Siskiyou, Rockies) with high fire risk in the western USA. 
• User-friendly, innovative LiDAR and imagery assessment tools to aid restoration practitioners and planners. 
• Tools and guidelines for restoration practitioners on the ground based on experimental restoration results.
• Publication of the models, tools, and experimental restoration results in accessible peer-reviewed journals.

Expected Outcomes

• Restoration of 4,300 acres and 12 stream miles in three National Forests.
• Lost meadow predictions for 3 major mountain ranges in the western USA.
• Strategy for incorporating meadow restoration with forest restoration planning efforts in fire-prone and post-fire landscapes.
• Online portal to access watershed and site assessment tools for meadow restoration planning.
• Workshops and trainings to broaden restoration capacity and showcase study findings.

Metrics of Success

• Research results comparing treatment and control meadows for groundwater elevations, inundation, stream discharge, soil carbon, wildlife use, and vegetation.
• Use of Lost Meadow model for watershed restoration planning by > 4 forests or tribal lands.
• Accessible maps and tools for meadow restoration planning.
• Increased application of process-based restoration approaches to stream and meadow restoration across western forests.

Geographies and Landscapes to be Addressed:

Trinity Forest Health and Fire-Resilient Rural Communities, Sierra and Elko Fronts, North Yuba, Klamath River Basin, Stanislaus National Forest