USDA Forest Service Pacific Southwest Research Station Meadow Research Initiative
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Project Goals and Objectives
The Pacific Southwest Research Station (PSW) and partners have completed the first three years of a meadow-scale restoration experiment to quantify the effects of process-based restoration to understand and communicate changes in hydrology, sediment transport, vegetation, and carbon sequestration in burned and unburned catchments in the Sierra National Forest (NF) and Plumas NF. Beaver dam analogs (BDAs) and other simple wood-based structures have been shown to be effective at reconnecting incised streams to their historic floodplains through ponding and sediment aggradation. This increased hydrologic connectivity leads to a myriad of positive changes in the meadow ecosystem, including increases in groundwater storage, meadow habitat diversity, and carbon sequestration. Researchers applied a before-after-control-impact study design with two treatment (impact) meadows in burned catchments, two treatment meadows in unburned catchments, and two untreated (control) meadows in burned catchments. One of each meadow type was located in the Sierra NF and Plumas NF, totaling six meadows. Infrastructure for monitoring was installed in summer-fall 2021 in all six meadows and included groundwater wells, stream gaging stations above and below each meadow, time lapse cameras, and permanent transects for soil and vegetation sampling. Meadows were monitored for at least one year before restoration, and treatments were completed by summer 2023. All restoration treatments were designed and implemented by project collaborator Swift Water Design, LLC using a beaver-inspired restoration approach, which aimed to slow and spread streamflow through the meadow, increase stream-to-floodplain connectivity, increase sediment capture in channel pools, and raise groundwater elevation. Crews used hand tools to build wood and sod structures at strategic locations to slow erosion at headcuts, spread flows into historic channels on the meadow surface, and dam water in incised channels to increase water depth, slow surface runoff, increase sediment deposition, and increase stream habitat diversity. Initial post-restoration results indicate the meadows quickly responded with higher groundwater elevations, ponding and sediment accumulation upstream of structures, increased wetted area of the meadows, and signs of changes in meadow vegetation. Monitoring is ongoing to better understand the longer-term effects and endurance of the restoration.
Structure Construction Elements
Beaver dam analogs (BDAs) and other simple wood-based structures (PALS, wood jams, ALS, mid-channel spanners, bank attached)
Project Photos
Cover Photo