Watershed assessments are often used to prioritize restoration, yet these assessments primarily focus on geomorphic conditions and less frequently incorporate abiotic factors, such as water chemistry and temperature, and biotic factors, such as the structure of food webs.
Using a dynamic food web model that integrates both abiotic and biotic river conditions, researchers simulated how juvenile salmon biomass responded to restoration at twelve sites in the Methow River in Washington. Some locations experienced relatively large increases in modeled fish biomass with restoration, whereas other locations were almost entirely unresponsive. Spatial variation among restoration outcomes was controlled primarily by non-geomorphic conditions, such as nutrient availability, water temperature, and stream canopy cover. Restoration responses also varied significantly with different food web configurations. Findings illustrate that ecological responses to restoration may vary substantially among river networks. Restoration planning would benefit from considering these commonly overlooked conditions.
Whitney, E., Bellmore, J.R., Benjamin, J.R., Jordan, C.E., Dunham, J.B., Newsom, M., Nahorniak, M., 2020, Beyond sticks and stones- Integrating physical and ecological conditions into watershed restoration assessments using a food web modeling approach: Food Webs, https://doi.org/10.1016/j.fooweb.2020.e00160