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Wet Meadow Ecosystems Climate Change Vulnerability, Adapta5on Strategies, and Management Implica5ons General Informa5on: © Wikimedia Wet meadows are well distributed across the Sierra Nevada at different eleva7ons, but account for only 1% of total area. The southern Sierra, with its steeper topography and drier climate, has less meadow area than the northern Sierra. Sierra Nevada wet meadows are largely defined by their hydrology; for example, meadows in mid-­‐ to high-­‐
eleva7ons usually receive water supply from snowmelt. Other water sources for meadows include overland flow, surface flow and/or groundwater entering via stream and spring networks, and direct precipita7on. Wet meadows are important ecosystems, providing key habitat for numerous species as well as a variety of ecosystem services including water filtra7on, aIenua7ng floods, aesthe7c value, and water storage, among others. Component species include: sedge species (Carex spp.), rush species (Juncus spp.), and tuNed hairgrass (Deschampsia cespitosa). Ecosystem Vulnerability: Moderate-­‐High Very Low Very High Wet meadows are highly sensi7ve to changes that impact hydrology, as meadow distribu7on, type, and vegeta7on are determined by local hydrological condi7ons. Climate and climate-­‐driven changes that may affect meadow hydrology include shiNs from snow to rain, reduced snowpack, earlier snowmelt 7ming, and increased evapotranspira7on. Non-­‐
climate stressors such as water diversions, grazing, recrea7onal ac7vi7es, and fire suppression can further increase meadow vulnerability by degrading their current condi7on and/or altering hydrology. Projected Climate and Climate-­‐Driven Changes Impacts on Regional Hydrology Impacts on Wet Meadows Decreased snowpack (-­‐64% to -­‐87%) •  Reduced spring and summer soil moisture •  Tree and shrub encroachment Earlier snowmelt and runoff 7ming & shiNs from snow to rain •  Advanced runoff center of mass (1-­‐7 weeks earlier) •  Flashier runoff, higher flow magnitudes but reduced mean annual flow •  Reduced groundwater recharge •  Longer dry season •  Erosion of topsoil and moist peat •  Channel incision and erosion leading to meadow drying •  Less water stored for use Increased evapotranspira7on •  Increased clima7c water deficit (i.e., reduced soil moisture) by up to 44% •  Tree and shrub encroachment Although wet meadows occur across a diverse eleva7onal range, their vulnerability is increased by low connec7vity and non-­‐uniform, fragmented distribu7on. In addi7on, wet meadows are one of the most altered and impacted systems in the Sierra Nevada; a degraded state reduces their ability to adapt or be resilient to climate and climate-­‐driven changes. Wet meadows fed by northerly exposed watersheds, in cold sinks, or in watersheds with minimal hydrologic altera5ons may be more resilient to projected clima5c condi5ons Adapta5on Strategies for Wet Meadow Ecosystems Adapta5on Strategy Specific Management Ac5ons Restore floodplain funcAon to enhance ecosystem integrity and resilience under climate change •  Plug and pond (redirect flow from incised channels to stable channel with broad floodplain) •  Establish setbacks •  Stabilize banks and headcuts •  Restore meanders, soils and structure •  Promote beavers where appropriate to keep water in the system Reduce negaAve impacts of grazing, as these impacts have the poten7al to amplify climate change effects •  Increase monitoring to include biological diversity indices that evaluate climate and non-­‐climate impacts and management ac7on effec7veness for key biological parameters •  Re-­‐examine livestock densi7es and grazing intensity, 7ming, and season in light of climate change predic7ons Increase role of fire to limit high severity fires, insect and disease outbreaks, and moisture stress •  Restore natural fire regime (wildland fire, prescribed fire, fire reintroduc7on) to minimize fuel loading and reduce poten7al for high severity fires •  Prac7ce fuels reduc7on Reduce negaAve impacts of recreaAon, roads, and trails to help wet meadows beIer cope with climate change effects •  Assess and consider removing roads (or altering 7ming of use) in sensi7ve meadows areas •  Enhance route designa7on plans in light of projected climate change impacts ©MaM Lavin Preven5ng anthropogenic degrada5on or hydrological altera5on of wet meadows can enhance resilience to climate change © Wikimedia Management Implica5ons This informa7on can be used in a variety of ways: ✔ Forest Plan Revisions ✔  U.S. Forest Service Climate Change Performance Scorecard: Element 6 -­‐ “Assessing Vulnerability” and Element 7 -­‐ “Adapta7on Ac7ons” ✔  Na7onal Park Service Resource Stewardship Strategies, Fire and Fuel Management Plans, General Management Plans, Strategic Plans, and Wilderness Stewardship Plans Further informa7on and cita7ons can be found in source reports, A Climate Change Vulnerability Assessment for Focal Resources of the Sierra Nevada and Climate Change AdaptaAon Strategies for Focal Resources of the Sierra Nevada, available online at the EcoAdapt Library: hIp://ecoadapt.org/library.