The responses of small mammals and lizards to post-fire succession and rainfall in arid Australia

We report a landscape-scale study investigating the responses of small mammals and lizards to fire in a central Australian hummock grassland. Vertebrates were surveyed on 26 study grids aged from 0 to >25 years post-fire. Analyses demonstrated that lizard and small mammal assemblages showed markedly different responses to each other with respect to post-fire vegetation succession. Lizard community composition could be arrayed along a single continuum of vegetation structure and conformed to a directional model for post-fire succession. In contrast, small mammal assemblages could not be arrayed along a continuum of post-fire vegetation succession. Geographical locality, rainfall, seedbank density and cattle grazing were prominent correlates of mammal assemblage structure. We propose a non-equilibrium state-and-transition model to describe small mammal community dynamics. This model has four temporal or geographical states that are characterized by different abundances of small mammals, and eight transitions that prompt shifts from one state to another. The model can be used to describe assemblage composition and identify areas or time periods when management activities should be implemented.