The waterside trail

Let’s see how we can support vital water sources through proper forest management.

Forest and mountain ecosystems are the source of more than 75 percent of our renewable water supply, delivering water to over half the world’s population. They are integral to our water security.

However, growing populations, increasing urban sprawl and shifts in land use and climate are having an impact on the quantity and quality of forest and mountain water.

Let’s examine specific forest ecosystem types to discover how sustainable forest management can support the water functions we depend on in our everyday lives.

Into the mangroves

Mangrove forests are commonly found along coasts, rivers and estuaries in the tropics and subtropics.

Some coastal tropical cities use mangroves as protective shields against the effects of coastal hazards that impact on people and infrastructure, as well as to treat wastewater and remove chemical contaminants. In terms of ecosystem services provided, mangroves are valued much more highly than other forests.

Also, the many species of fish and invertebrates that live in mangroves (or access them during flood tides), provide a source of protein for humans, other wildlife and livestock. In fact, approximately 80 percent of the worldwide fish catch is estimated to depend directly or indirectly on mangroves.

Integrating mangroves into disaster risk reduction strategies and coastal management planning can help reduce the risk of coastal disasters and preserve livelihoods.

Welcome to the peatland

Wetland forests growing on peat soils are the world’s most carbon-dense terrestrial ecosystem. Their conservation is one of the most cost-effective ways to decrease greenhouse-gas emissions.

In peatland forests, trees and vegetation like mosses are also essential for flood and drought mitigation. And because they help with the maintenance of water quality at the catchment level, drinking and irrigation water is often extracted from peatlands.

However, it is estimated that between 1990 and 2008, one quarter of the world’s peatland forests disappeared. It’s important that any investment in the sustainable use of peatland forests recognizes that low-impact, mixed-livelihood activities such as ecotourism, fisheries, agriculture and forestry are possible.

Up in the clouds

Tropical montane cloud forests can be defined simply as forests that are frequently covered in cloud or mist. Because they are in areas with high rainfall, they generally have high water yields, influencing the amount of available water and regulating surface and groundwater flows.

This forest type is important in the protection of soils as they are often found on steep slopes, which tend to be highly susceptible to erosion and mass movement if the forests are removed.

But tropical montane cloud forests are rare and their conservation needs strengthening. In particular, because they are a hotspot for biodiversity conservation, their conversion to agricultural land uses should be avoided. Their management should aim to integrate multiple ecosystem services, including those related to water, soil and biodiversity. Payment for watershed services (PWS) schemes have been popular as a means to compensate landowners and thereby reduce deforestation and water scarcity.

In the drylands

Most dryland forests are in the semiarid and dry subhumid zones. Dryland trees and shrubs have developed effective functional adaptations to cope with the combination of high temperatures and water scarcity.

Dryland forests and trees survive and grow on limited water resources. But while water is limited, it is essential for ensuring the provision of goods (like food, fuel and more) from dryland forests and trees. Water availability impacts not just the production of particular goods and services but also their long-term sustainability.

Dryland forests require ‘ecohydrologic forest management’ that determines the trade-offs between water and vegetation. This means modifying forest and tree cover and species composition according to the local balance between water availability and consumption. Strategies like canopy opening, pruning and species selection can combat water scarcity while also increasing climate change resilience and adaptation.

How we can make a difference

A growing human population and a changing climate have put pressure on many ecosystem services, increasing the need to manage forests for water.

FAO’s Guide to Forest-Water Management provides extensive guidance and recommendations on how to manage forests for their water ecosystem services. It also offers insights into the business and economic cases for managing forests for water ecosystem services.

Given the importance of water for domestic, agricultural and industrial purposes, a strong argument can be made that maintaining and enhancing the water services of forests should be a high priority. What would that mean for forest management? What would managing forests for water look like? This report aims to answer these questions (and more).