On March 1, the UN General Assembly declared 2021 – 2030 the UN Decade on Ecosystem Restoration, boosting the topic of restoration in climate agendas at all scales. 57 countries, subnational governments and private organizations have currently committed to bring over 170 million hectares under restoration, and existing global restoration goals will likely accelerate to achieve the Bonn Challenge aiming to restore 350 million hectares of degraded ecosystems by 2030.

Forest landscape restoration involves processes aimed at regaining ecological functionality of degraded or deforested forest landscapes, while enhancing human well-being. Restoring forest landscapes enhances the provision of ecosystem services, and enhancing water provision services is a common target in forest restoration projects. However, the link of forest landscape restoration and water yields is complex, may depend on numerous factors and a lot is still unclear and disputed.

A recent review of studies on how restoration affects water reports that 80% of studies found a negative impact of forest restoration on water availability on an annual basis. However, the results look different when considering different seasons: 40% of studies find forest restoration has a positive effect on water availability during the dry season. Furthermore, 83% of studies report on increased infiltration capacity in restored forests, which indicates the recovery of key hydrological processes that sustain water yields. Finally, longer-term studies show that initial drops in annual water yield recover over time.

Projects in the field indeed have shown positive hydrologic responses, improving ecological and economic benefits. A project in Chile, restoring riparian areas, enhanced water supplies for people living downstream and established payments to farmers for restoration efforts. Similarly, restoring forests in the Nosara River Basin of Costa Rica has improved water supply and created jobs.

Considering the results achieved in different regions around the globe provides some lessons regarding the relationship between forest restoration and water. Forest landscape restoration can be designed for water, but it is important to understand and adapt plans to local specificities (social, economic and environmental). As always in forest management, no one recipe of forest landscape restoration for water fits all.

How do your forest landscape restoration projects maximize water-related ecosystem services? Do you have any lessons learned to share?