A study by UBC Okanagan researchers, published in Proceedings of the National Academy of Sciences, reveals that forest loss and fragmentation significantly affect how watersheds store and release water. Analyzing data from 657 global watersheds, researchers found that increased forest loss results in a higher proportion of "young water," which indicates rapid water movement through a watershed, thus reducing water storage in soils and groundwater for drier periods.
The study emphasizes that it’s not just the quantity of forest that matters but also its spatial arrangement. In areas with low forest cover (below 40-50%), the arrangement of remaining patches can worsen or mitigate the impact on water movement. Notably, more edges between forest and cleared land can reduce young-water fractions due to increased solar exposure and evapotranspiration. In contrast, in densely forested areas, spatial arrangement has less effect.
With extreme weather pressures on water resources, the research underscores the importance of nuanced forest and watershed management to enhance long-term water availability.
