Forward-looking analyses are needed to anticipate changes to ecological systems and consequences for habitats and wildlife. Scoping analyses are also needed to gauge the ability of conservation actions to keep pace with impacts and compare returns on different conservation investments. Yet, few tools and modeling approaches can explicitly link environmental change with habitat conditions and population states, to project species persistence. To test the ability of individual-based models to support such scoping assessments, we constructed several spatially explicit individual-based (HexSim) models to quantify the impacts of climate change, development, invasion, and disease, as well as the potential benefits of habitat restoration, translocation, captive breeding and release, predator reduction, and food supplementation. We constructed realistic habitat-population-stressor systems for bird and mammals of conservation interest in Canada and the U.S., and projected historical, contemporary, or future changes to identify key factors driving population decline. We used scenario modeling to explore uncertainty in imprecise data, future conditions, and alternative conservation actions.
Results/Conclusions
Individual-based models were successful at synthesizing divergent types of information including maps, statistics, mechanisms, relationships, and local knowledge, and yielded simplified but realistic analogs of wildlife systems. Climate-impact models demonstrated that accounting for linked climate, habitat conditions, and population states can nuance range contraction projections by accounting for biological limitations such as dispersal, social behavior, and habitat needs. Models that evaluated different conservation actions were able to rank-order the number of individuals gained by different actions, but the effectiveness of actions differed among ecological settings. The success of habitat restoration was highly dependent on matching the species needs with the scale of planned habitat restoration. For example, simulated conservation actions for the Greater sage-grouse yielded benefits ranging from indiscernible (small changes) to highly effective at increasing population abundance and persistence, if vegetation was restored over large areas. We conclude that integrative simulation models can be effective at synthesizing disparate data, creating a data-driven understanding of the system, and actively engaging multiple partners in scoping the importance of environmental changes. HexSim and similar models can support conservation planning by estimating the return on conservation investments and designing actions while conservation options still exist.
