Shedding light on the complex relationship between forest restoration and water services

Abstract

Although native vegetation is a determinant of aquatic ecosystems' maintenance, forest restoration has been linked to decreases in water yields worldwide. Here, we clarify linkages between forest restoration and water services and identify gaps in the literature critical for evaluating the benefits of forest restoration on water yields. Also, we discuss possible strategies to improve forest restoration planning and implementation. We argue that the apparent disconnect between estimates in the literature and real‐world observation reflects the limitation of studies, methods, and approaches in capturing forest and water relationships' complex nature. Future research should focus on hydrologic parameters other than annual streamflow flow (such as infiltration, groundwater recharge, and flow regulation) and encompass broader spatial–temporal scales. More empirical studies are needed, especially in the tropics, as the forest–water dynamics in these areas are unique and poorly understood. Filling this gap is critical to improving the decision‐making process related to water management and governance.

Ecological restoration and water‐related ecosystem services, one step ahead: a reply to Dib et al. (2023)

“…Hydrological Rules Are Global, and So Is the Need for Freshwater Although Dib et al (2023) argue that "hydrometeorological processes in the humid tropics differ from other regions" and that "the forest-water dynamics in the tropics are unique," we counterargue that the components and fluxes of the water cycle are the same in the whole planet, and so are the general rules, such as "increasing forests generally decreases annual water yield on a local scale." They also consider that estimates in the literature and real-world observation on the relationships between forest restoration and water yield are inconsistent, this being a crucial gap to support restoration planning and implementation.…”

“…Negative Impacts of Planting Trees on Annual Streamflow and Groundwater Recharge Will Likely Not be Reverted With Forest Age Dib et al (2023) suggested that decrease in water yield in the first years of forest growth will gradually recover over time. If that was true, the expected role of restored forests as rainmakers would also decrease over time, because the amount of water extracted from the soil and launched to the atmosphere would decrease with age of planted trees.…”

“…If that was true, the expected role of restored forests as rainmakers would also decrease over time, because the amount of water extracted from the soil and launched to the atmosphere would decrease with age of planted trees. However, besides using in this section the incomplete definition of evapotranspiration (omitting rain interception) and citing secondary forests as proxies of restored forests to support their arguments, Dib et al (2023) recognized that "strong evidence for this hypothesis is still needed".…”

“…In their opinion article, Dib et al (2023) reported the benefits and some negative outcomes of forest restoration and discussed possible strategies to improve the decision‐making process related to water management and governance. They argue—and we agree with them—that designing the best restoration strategy regarding where and how the interventions should be implemented must consider who benefits from or might be impacted negatively by the consequences of planting trees.…”

On the unique value of forests for water: Hydrologic impacts of forest disturbances, conversion, and restoration

“…Tree plantation and management regime type presumably also have far‐reaching consequences for water (Baral et al., 2016; Feng et al., 2022; Ferraz et al., 2013; Jones et al., 2017; Messier et al., 2022). Future research on change in hydrological processes should focus on other parameters in addition to annual streamflow flow and water yields (such as infiltration, groundwater recharge, and flow regulation), and should encompass broader spatial–temporal scales to include impacts on downwind basins (Dib et al., 2023; Ellison, 2018).…”