Approach
This approach outlines tactics that managers can apply to wetland ecosystems most susceptible to impacts from warming waters. Urban wetlands are particularly vulnerable to increased stream temperature. Warming in rural or remote wetlands may also be a concern, especially in bog and fen peatlands at northern latitudes. Cool substrates are a defining trait of these northern peatlands, therefore warming induces compositional shifts and loss of stored carbon and other ecosystem functions.
Tactics
- Reconnect floodplains and wetlands to surface waterways to increase groundwater recharge and promote flow of cool groundwater in the system.
- Maintain and restore groundwater-fed headwater wetlands to promote cooler, late summer flows to downstream wetlands.
- Modify dams and impoundments from top-draw to bottom-draw structures to release cold water from lakes or reservoirs.
- Reduce urban development and incorporate nature-based infrastructure and forested buffers near high quality, sensitive wetlands and riparian areas to limit the “urban heat island effect” and warm storm water runoff.
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.