Forests Water Guidelines

Many people worldwide lack adequate access to clean water to meet basic needs, and many important economic activities, such as energy production and agriculture, also require water. Climate change is likely to aggravate water stress. As temperatures rise, ecosystems and the human, plant, and animal communities that depend on them will need more water to maintain their health and to thrive. Forests and trees are integral to the global water cycle and therefore vital for water security – they regulate water quantity, quality, and timing and provide protective functions against (for example) soil and coastal erosion, flooding, and avalanches. Forested watersheds provide 75 percent of our freshwater, delivering water to over half the world’s population. The purpose of A Guide to Forest–Water Management is to improve the global information base on the protective functions of forests for soil and water. It reviews emerging techniques and methodologies, provides guidance and recommendations on how to manage forests for their water ecosystem services, and offers insights into the business and economic cases for managing forests for water ecosystem services. Intact native forests and well-managed planted forests can be a relatively cheap approach to water management while generating multiple co-benefits. Water security is a significant global challenge, but this paper argues that water-centered forests can provide nature-based solutions to ensuring global water resilience.

This work advises owners and managers how woodlands and forests influence the freshwater ecosystem, and gives guidance on how operations should be carried out in order to protect and enhance the water environment. The guidelines apply equally to forest enterprises and the private sector.

Forests are intrinsically linked to water – forested watersheds provide 75 percent of our accessible freshwater resources (Millennium Ecosystem Assessment, 2005) – and both forest and water resources are relevant to the achievement of all 17 Sustainable Development Goals. Despite the important interlinkages, the forest-water nexus is often unaccounted for in policy and planning. For example, three quarters of forests are not managed for soil and water conservation, which poses a fundamental challenge to achieving sustainable and resilient communities and ecosystems. It is paramount to employ an integrated approach to forest and water resources in management and policy that takes into account the complexity and contextual nature of forest-water relationships. To achieve this, we must improve our understanding of forest-water relationships within local contexts and at different scales, as well as our ability to design, implement, and learn from landscape approaches that both rely on these forest-water relationships, and impact them. In this context, FAO’s Forest and Water Programme has developed a module-based capacity development facilitation guide for project and community stakeholders involved in forest, water and natural resource management to ensure we apply our knowledge to better manage forests and trees for their multiple benefits, including water quantity, quality and the associated socio-economic benefits that people within and outside forests so heavily depend on.

Of all the outputs of forests, water may be the most important. Streamflow from forests provides two-thirds of the nation's clean water supply. Removing forest cover accelerates the rate that precipitation becomes streamflow; therefore, in some areas, cutting trees causes a temporary increase in the volume of water flowing downstream. This effect has spurred political pressure to cut trees to increase water supply, especially in western states where population is rising. However, cutting trees for water gains is not sustainable: increases in flow rate and volume are typically short-lived, and the practice can ultimately degrade water quality and increase vulnerability to flooding. Forest hydrology, the study of how water flows through forests, can help illuminate the connections between forests and water, but it must advance if it is to deal with today's complexities, including climate change, wildfires, and changing patterns of development and ownership. This book identifies actions that scientists, forest and water managers, and citizens can take to help sustain water resources from forests.

This open access book introduces the function, implementation and governance of green infrastructure in Japan and other countries where lands are geologically fragile and climatologically susceptible to climate change. It proposes green infrastructure as an adaptation strategy for climate change and biodiversity conservation. In the face of climate change, dams, levees and floodways built as disaster prevention facilities do not sufficiently function against extraordinary events such as mega-floods and tsunami disasters. To prevent those disasters and loss of biodiversity in various ecosystems, we should shift from conventional hard measures to more adaptive strategies using various functions that natural and semi-natural ecosystems provide. Green infrastructure is an interconnected network of waterways, wetlands, woodlands, wildlife habitats and other natural areas that support native species, maintain natural ecological processes, sustain air and water resources and contribute to the health and quality of life for communities and people. Green infrastructure has mainly been discussed from adaptation strategy perspectives in cities and urban areas. However, to protect cities, which are generally situated at downstream lower elevations, we explore the preservation and restoration of forests at headwater basins and wetlands along rivers from a catchment perspective. In addition, the quantitative examination of flood risk, biodiversity, and social-economic benefits described in this book brings new perspectives to the discussion. The aim of this book is to accelerate the transformative changes from gray-based adaptation strategies to green- or hybrid-based strategies to adapt to climate change. The book provides essential information on the structure, function, and maintenance of green infrastructure for scientists, university students, government officers, and practitioners.