Using Individual Based Models to Explore Interspecific Interactions Between Trout, Beavers and Humans in Stream Restoration

We have constructed an individual based model of co-occurring trout and beaver populations that allows the exploration of fish population dynamics as a function of stream habitat quality and quantity.  We based the simulation tool on the Bridge Creek (John Day River basin, Oregon) IMW where we have implemented a large-scale restoration experiment by partnering with an existing beaver population.  Extensive monitoring captured geomorphic and riparian changes, as well as fish and beaver population responses; information we use to parameterize the model as to the geomorphic and fish response to dam building beavers.  Key to this restoration scenario development tool is the ability to manipulate stream habitat quality and quantity directly through restoration actions (beaver dam analogs, or BDAs) and indirectly through the dynamics of the co-occurring beaver population.  The rehabilitation of stream systems is seen as one of the primary means by which population and ecosystem recovery can be achieved, and given the role beaver play in structuring stream habitat, managing the population dynamics of beavers can be a powerful tool to manage stream habitat rehabilitation.  However, since the effects of dam-building beaver can be mimicked with BDAs, what tradeoffs exist between these two complementary forms of stream restoration?