Home » Manage Rivers, Lakes, and Other Freshwater Ecosystems for Climate Change
Due to climate change, rising air temperatures are already warming freshwater ecosystems. Some lakes and streams have already experienced water loss due to summer droughts. These and other changes, are likely to continue and accelerate in the coming decades and impact water quality and quantity, presenting negative implications for freshwater ecosystems and the species that rely on these vulnerable habitats.
Freshwater systems include large lakes, ponds, rivers, wetlands, streams, and seasonal vernal pools. The response of these ecosystems to climate change impacts will vary based on current conditions, regional changes in temperature and precipitation, and more.
Observed and predicted climate change impacts to freshwater ecosystems include:
Warmer water, earlier snowmelt, and the increased severity and frequency of both floods and droughts will impact freshwater ecosystems across the United States.
Despite management challenges, land trusts are well positioned to manage rivers, lakes and other freshwater habitats for the multiple benefits – both ecological and economic – they provide. As the Ecological Society of America relates in Sustaining Healthy Freshwater Ecosystems, there is growing recognition that functionally intact and biologically complex freshwater ecosystems provide many economically valuable commodities and services to society. These services include flood control, transportation, recreation, purification of human and industrial wastes, habitat for plants and animals, and production of fish and other foods and marketable goods. Over the long term, intact ecosystems are more likely to retain the adaptive capacity to sustain production of these goods and services in the face of future environmental disruptions such as climate change. These ecosystem benefits are costly and often impossible to replace when aquatic systems are degraded. For this reason, deliberations about water allocation should always include provisions for maintaining the integrity of freshwater ecosystems. Aquatic ecosystems can be protected or restored by recognizing the following:
New policy and management approaches will be required to protect aquatic ecosystems and their functions. The conservation community is already engaged in watershed protection to improve water quality, reduce flooding impacts, and enhance valuable habitat. For example, the Elkhorn Slough Foundation in California has targeted land acquisition and restoration projects to restore and reconnect floodplains to improve habitat and ecosystem health. In the Midwest the Southwest Michigan Land Conservancy (SWMLC) similarly focuses land management and acquisition efforts on maintaining and improving natural communities. SWMLC’s stewardship efforts include removing vegetation that is uncongenial to infiltration of rainwater, and restoring remnant lake plain prairie habitats for the multiple flood control, water quality, and habitat benefits these systems provide. Read more examples of land trust efforts to protect and improve water resources. Land trusts working to manage rivers, lakes and other freshwater habitats may wish to:
The sustainability of aquatic ecosystems can best be ensured by maintaining naturally variable flows, adequate sediment and organic matter inputs, natural fluctuations in heat and light, clean water, and a naturally diverse plant and animal community.
The Ecological Society of America (ESA) details management challenges and provides guidance to support water resource management in Sustaining Healthy Freshwater Ecosystems. Key recommendations the land trust community can incorporate into acquisition and management practices include:
While international in focus, the World Bank's Flowing Forward report also provides relevant information about climate impacts, vulnerability assessments, and adaptation options for freshwater ecosystems.
Land trusts are engaging in strategic conservation planning to build resilience and minimize vulnerabilities to impacts of climate change in different ways. Learn more.