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Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. In Brief Climate Change and Water Perspectives from the Forest Service | N v „ Freshwater availability is an increasing concern across the globe and it may be the most important natural resource issue ;.'._;i of the century. Climate change and its effects on water are expected to intensify freshwater scarcity and conflict. A >. forthcoming Forest Service, U.S. Department of Agriculture report will highlight the importance of managing forests to provide clean, abundant water. The report will explore likely impacts of climate change on the Nation’s forested watersheds and describe how natural resource managers can incorporate a climate change perspective into watershed stewardship. The cleanest water flows from healthy, forested Climate change will impact the ability of the Nation's watersheds. forests to provide water and other critical watershed services. Warming over the past several decades has funda¬ Of the many ecosystem services provided by forests, water¬ mentally altered the hydrologic cycle, and these changes are shed services are among the most valuable. Healthy forests percolating through our watersheds (see illustration below). capture and store water, naturally regulate streamflows and Snowpacks are shrinking and stream temperatures will likely water quality, reduce flood and storm damage, control increase. Precipitation patterns may change, and floods, erosion, and replenish ground water. High- droughts, and severe weather disturbances may become elevation forests protect and enhance our more common. water supplies downstream. Forests in the Climate change is hydrologic change. United States provide Forests provide nearly two-thirds of drinking water to more the freshwater in the 48 conterminous Water supplies stored as snow cover in high-elevation forests States—water that fills our are particularly vulnerable to climate change and are pro¬ than 180 million rivers, lakes, and streams; jected to decline over the course of the century. Earlier spring people. sustains fish, plants, and runoff and reductions in low flows will reduce water availabil¬ Sixty-six million wildlife; supports food, ity downstream during the summer and fall months. Higher people rely on a energy, and industrial water temperatures, flooding, and droughts will affect water aGB842 national forest as their production; enables quality and exacerbate water pollution. . C58 2008 k water source. navigation; and pours from the faucets of our The Forest Service is a steward of the Nation's homes and businesses. forested watersheds, ensuring a continued supply of high-quality water and watershed services as Projected climatic changes we adjust to a changing climate. to the hydrologic cycle Glaciers are reduced or Less precipitation in More intense storms with eliminated. Increased some areas, more in other more flooding and extreme high elevation erosion. areas. Greater interannual winds. variability. More evapotranspiration. More rain and less snow. Drier vegetation and Snow melts sooner in soils. More frequent and Spring. severe droughts. Increased wildfires and area burned. Earlier spring runoff. Larger flood peaks. Less summer stream flow. Smaller headwater stream networks. Sea level rises. More coastal erosion. Saltwater intrusion into coastal freshwater Water in streams and lakes aquifers. becomes warmer. In Brief: Climate Change and Water Climate change will affect water availability—quantity, quality, As populations, incomes, and consumption levels increase, timing, and distribution—and other watershed services. It people put more pressure on our forested watersheds to de¬ will affect the people who rely on water for liver the services they want and need. Declining water quanti¬ everyday use (see table below). ty and quality are becoming common issues, especially where our demands exceed supply. Growing water demands, in turn, Availability of clean drinking put aquatic resources and other services at risk because less water is a critical issue for most water is available to sustain them. Many municipalities, busi¬ people in the world. Seventy nesses, farmers, and citizens already face difficult decisions percent of the Earth's surface is about how—and where—to get their water. Future changes covered by water, but less than 1 in the timing, magnitude, and quality of waterflows resulting percent of this amount is freshwater, from climate change will compound these water challenges. present on the land surface, in the Caring for the Nation’s forests will help protect atmosphere, or in the ground. Forty percent of A small fraction of the world's watershed services into the future. the world’s population freshwater is renewable and available for human use, and We may not be able to precisely predict the extent, location, will be living in water-scarce this water supply is unequally or timing of climate change impacts, but we can recognize regions by 2025. distributed across the ecosystem changes and respond with flexible and adaptive World Resources Institute, United Nations continents. Seasonal watershed management strategies. The following f Environment Programme, and World Business differences in precipitation, actions will help resource professionals and landowners Council for Sustainable Development, 2002 waterflows, and demand mean incorporate a climate change perspective into their work. that freshwater is not always available when and where it's needed. Prepare for change Preparing now to face future challenges is essential. — -=='—— \ Adaptive management is an approach that promotes learning • Managers, planners, and conservation groups can use through doing. This approach involves actively making existing information to identify watersheds and services decisions and monitoring results to improve our understanding that are most vulnerable to adverse changes. Planning for about the complex systems we manage. change and priority-setting will need to begin with the most vulnerable and highest value watersheds. Three examples of current and projected climatic changes, their effects on ecosystems, and potential consequences to the supply and delivery of watershed services. Climatic changes are based on current trends and projections from the Intergovernmental Panel on Climate Change Fourth Assessment Report (2007). For all changes, uncertainty is substantial and the geographic variability is expected to be high. * = probable increase, * = probable decrease, a = change Consequences for Climatic Changes Location Ecosystem Effects Watershed Services Warmer air temperatures Widespread ^ Precipitation as snow; faster and earlier A Amount, type, quality, and distribution of Greatest change in mountains and snowmelt aquatic habitat and biota northern latitudes * Evapotranspiration and primary productivity A Water availability and recreational and t Water temperatures cultural experiences * Sea level; coastal erosion and saltwater ^ Water quality and timing intrusion into freshwater supplies Function and operation of existing water infrastructure in coastal areas Less winter precipitation at lower Snow; changes in streamflow timing * Water supplies for people, agriculture, latitudes (Southwest. Intermountain * Risk of disturbance, e.g., drought, wildfires, energy, and other uses Changes in precipitation patterns West) insects, disease * Water demand, ground water withdrawals, (projected changes vary by location and Vegetation growth; changes in composition and consumptive use of surface waters have substantial uncertainty) Fisheries and water-based tourism More precipitation at higher latitudes t Streamflow t Freshwater supplies (Pacific Northwest, New England) A Vegetation growth and composition t Improvements in warm water fisheries t Soil erosion and landslides i Greater variability in precipitation Everywhere t Variability in stream, lake, and riparian habitats f Uncertainty in water supply from year to year t Risk of aquatic and riparian species extirpation 4< Uncertainty for reservoir operations t Soil erosion, stream and lake sedimentation, * Risk to aquatic habitat and water supply More extreme floods and droughts and landslides infrastructure • Broad-scale inventories, assessments, and early-warning Active management will need to... monitoring can help managers identify trends, anticipate ■ Restore meadows, wetlands, and floodplains to effects, and act quickly to limit loss or reduction in critical improve natural storage, reduce flood hazards, and watershed services. prolong seasonal flows ■ Protect and restore riparian forests to moderate • Ensuring that land managers, landowners, and changes in stream temperature decisionmakers can access people with skills and training in ■ Remove migration barriers and reestablish habitat water resources will be important as climate change further connectivity to help species adapt to changing complicates issues. conditions ■ Reduce flood and wildfire risks in vulnerable water¬ Advance and share knowledge about sheds to prevent erosion and maintain clean water and climate change water supplies Together, scientists and managers can provide new ■ Improve or decommission roads to reduce adverse information and tools for the management toolbox. impacts during large storms • New information will be needed to track and evaluate Support entrepreneurial projects and leaders changing watershed conditions, understand the effects of New approaches to watershed management will help us meet management practices, and forecast quality, quantity, and future challenges. timing of water supplies. New technologies will be needed to improve data collection. Dynamic, process-based models • Management approaches will need to be flexible and will be needed to improve climate change projections and forward-thinking, with a focus on desired processes and evaluate management options. benefits rather than individual species and specific, static conditions. • National forests and experimental research sites will con¬ tinue to serve as learning laboratories to help land managers • Demonstration projects that integrate science and understand interactions between climate and ecosystems, management will foster innovation and provide new evaluate management options, and test solutions. information for land managers and the public. • Intensive cooperation between scientists and land • Emerging ecosystem markets can align economic interests managers in both natural and social sciences will promote with conservation objectives, and new market opportunities adaptive management and learning. can provide incentives for private landowners to maintain and improve watershed services. Manage for watershed resilience and enhance ecosystem adaptability Healthy, resilient watersheds are the best insurance policy for a Vital signs of a healthy, resilient watershed changing climate. Resilient ecosystems are those that rebound after dis¬ • Managing wildland and urban forests for a set of watershed turbance and continue to provide ecosystem services. services—like high water quality, flood control, and fish A healthy, resilient watershed has the capacity to: habitat—ensures that management and land use decisions Capture and store rainfall are designed to maintain and protect healthy watersheds. Recharge ground water reservoirs Minimize erosion losses and protect soil quality • Public forests will continue to serve as natural reservoirs for Sustain and regulate streamflows high-quality water and as refuges for biodiversity. Store and recycle nutrients Support natural riparian and floodplain functions • Current management practices applied broadly, more Provide habitat for native aquatic species strategically, and in new ways can help watersheds adapt to Resist and recover quickly from floods, fire, insect change. Best management practices protect watersheds that outbreaks, and other extreme events are actively managed, and restoration activities reestablish Adapted from: Sprague et al. [eds], 2006. The State of Chesapeake Forests. The processes or services that have been lost or are at risk. Conservation Fund and the Forest Service. NATIONAL AGRICULTURAL LIBRARY 022564708 Connect with partners and the public We will need to step across boundaries to expand our reach. • Creating and cultivating effective partnerships will promote collaborative action across larger landscapes. Reaching out to new partners, such as developers, health and environ¬ mental organizations, private businesses, municipal water managers, and city planners, will increase awareness about the critical role of healthy forested watersheds. • Conserving water will keep water in streams and help to sustain healthy watersheds. We can all lead by example and reduce our water footprint, encouraging others to make similar commitments. • Connecting people to their water source will have a lasting effect on watershed stewardship. The Forest Service Climate change is a formidable challenge and there is much The National Forest System was established with the purpose we can do to respond. Actions taken now can minimize poten¬ tial negative impacts and unlock new opportunities— of “securing favorable conditions of waterflows” in the Nation’s headwaters. For over a century, the Forest Service has they must include a focus on water. protected water and managed public forests to provide the The mission of the Forest goods and services that people want and need. Service is to sustain the health, diversity, and productivity of State and Private Forestry extends the Forest Service mission the Nation's forests and to urban and community forests and to more than 400 million grasslands to meet the needs acres of private land. Nearly 60 percent of the Nation’s forests of present and future are privately owned—the people who own and manage these generations. This mission lands serve as stewards of the Nation’s water supply and other rests on a tradition of ecosystem services that benefit society. managing forests to protect the Nation's clean water In 1910, Forest Service Research established its first supplies. Today, our commit¬ experimental watershed to conduct research that informed ment to watershed stewardship management and policy on public and private lands. This is even more critical as we tradition continues today with a wide array of partners. respond to new challenges like climate change. Through research, International Programs works with agencies, countries, and partnerships, and mindful, meaningful nonprofit partners to assist others around the world in management, we will enhance the ability of the protecting and managing natural areas. Nation's watersheds to adapt to change and continue to support the health and well-being of http://www.fs.fed.us people and ecosystems. forests, controlled sources and recycled wood or fiber FS-908 Cert no. 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