Approach
Reducing the rate and magnitude of soil erosion and sedimentation is an important step in both resisting transformative changes and improving the resilience of wetlands and riparian areas to absorb frequent and severe disturbances and extreme rain events. Sedimentation increases nutrient availability in wetlands resulting in deleterious effects on ecosystem function and quality. In particular, reductions in the water holding capacity of wetland soils buried by sediment alter the rate of nutrient cycling. Sediment build-up can also bury native seed banks. Intensive land-use activities can significantly accelerate the rate and magnitude of erosion and sedimentation occurring on-site, resulting in Influxes of phosphorus from sediment deposition that can have negative effects. As hydrologic regimes intensify, altering land-use zoning to protect wetlands, implementing best management practices (BMPs) in forestry and agricultural operations will be of utmost importance to sustaining soils and wetland ecosystems into the future.
Tactics
- Where roads cross streams and wetlands, create vegetated ditches with waterbars and bioswales uphill of crossing to reduce runoff and sedimentation.
- During forestry operations in sites adjacent to open wetlands, meet or exceed standards for forestry BMPs for water quality.
- If agricultural producers work near the wetlands that you manage, encourage them to work with their local NRCS Conservationist to develop a ‘Cropland Conservation Management System’
- In areas of erodible soils, employ proper road construction maintenance, erosion control measures, and increase forested acreage adjacent to open wetlands to "Slow the Flow" of runoff to limit the formation of gullies or ravines.
- Preserve and restore large-scale acreages of perennial vegetation adjacent to wetlands.
- Employ and maintain approved methods for managing sediment transport in dam regulated systems to limit sedimentation impacts to riparian wetlands.
Strategy
Strategy Text
Approaches outlined by this strategy provide managers with adaptation options aimed to sustain or enhance the quality of wetland habitats susceptible to warming waters and reduced water quality. Warmer water increases the rate of algal growth, changes dissolved oxygen levels and water chemistry, increases decomposition rates, and shifts species composition by altering abundance or cover of existing species and encouraging invasion of non-native species. Increased frequency of large storm events resulting in greater runoff may increase heavy nutrient loading. This adaptation strategy applies to managing the quality of all wetland types, but especially mesotrophic wetlands (e.g., poor coastal fens and inland fens) that are maintained by a delicate balance of hydrologic inputs (groundwater, surface water, and precipitation) and ombrotrophic peatlands (e.g., precipitation-dependent bogs). Wetland managers may already focus on protection of water quality in their management activities, as nutrient enrichment and sedimentation are among the leading causes of current wetland degradation. The likelihood of more extreme precipitation events further amplifies the risk of harmful chemical-laden runoff from adjacent land-uses, particularly in agricultural or urban areas. This strategy addresses the additional protection and focus necessary to ensure clean water inputs to wetland areas. Further, management of wetland processes, given changes in climate, has local and global implications, particularly for wetlands known to sequester large volumes of carbon in soils (e.g., peatlands). Reducing excess nutrient inputs that speed up decomposition rates in organic-rich wetlands (e.g., peatlands) can improve long-term sequestration of CO2 in wetland soils and mitigate future greenhouse gas emissions.