Effects of temperature and surface water availability on spatiotemporal dynamics of stream salamanders using pattern-oriented modelling

Ecological models are powerful tools for generating predictions about the viability of populations of endangered species, especially in landscapes where they may be subject to complex, cross-scale disturbances. Spatially explicit, individual-based approaches are particularly promising due to their ability to simulate the effect of landscape level changes in habitat on individual-level behaviour, thus predicting possible emergent responses from the bottom up. We apply this approach to modelling the movement behaviour and the complex life cycles of two species of stream-dwelling salamanders (the Allegheny Mountain Dusky Salamander, Desmognathus ochrophaeus, and the Northern Spring Salamander, Gyrinophilus porphyriticus) in response to a spatially and temporally varying environment. Despite the poor state of ecological knowledge about these species, our model provides reasonable predictions about life cycle, as well as the density and distribution of salamanders. When tested with a dynamic, drought prone environment, the model predicts viability levels that are biologically plausible. By simulating the cross-scale interactions between organisms and their environment, individual-based models such as we have developed here provide a new tool for in silico investigations of the expected impacts of varying landscape scenarios and environmental changes.