Forest Management Tools to Maximize Snow Retention under Climate Change

Climate change is projected to cause earlier and less snowmelt, potentially reducing water availability for terrestrial and aquatic ecosystems and for municipal and agricultural water supplies. However, if forested landscapes can be managed to retain snow longer, some of these environmental and financial impacts may be mitigated. Results from our research team demonstrate that in the Pacific Northwest (PNW), opening dense forest canopies through creating forest gaps will generally lead to more snow accumulation and later melt (i.e., up to 13 weeks later). However, under certain conditions, such as locations on ridges with high wind speeds and sunny south-facing slopes, the snow that accumulated in the forest is likely to melt more slowly and disappear later. Our research analyzed forest effects on snow in the mountains across the diverse climate gradients in the Pacific Northwest, where we made careful observations at field sites and additionally incorporated citizen science. Working with regional forest and water managers, we developed a decision tree model to help managers to act strategically to maximize snow retention (protecting forests in some areas while opening gaps in others), providing more water later in the season for hydropower, agriculture, and fish flows. agriculture, and fish flows.