Forest watershed management, water yield, and climate change

Charley presented a poster this week on our Coweeta Water Yield project at the 8th North American Forest Ecology Workshop held in Roanoke, VA.  She presented results from a modeling study where we investigated how forest management and climate change may interact to cause unexpected changes in water yield.  The extensive datasets from the paired watershed studies at the Coweeta Hydrologic Lab were used for the analysis.  The nonlinear model accounts for the response of vegetation removal and regrowth and it uses water yields ranging from low (1st percentile) to high (99th percentile) flow and thus provides an indication of the interaction response across the entire flow regime.  We found that the interaction term was more often significant at the extreme flows, especially at the high flows.  This suggests that the effect that forest management has on water yield depends on the precipitation.  Therefore, climate change patterns should be considered when managing forests for water yield.