Risk, Reward, And The Role Of Habitat Selection On Community Dynamics In Temporary Ponds

The processes that generate patterns of species diversity within and among habitat patches are a fundamental topic of interest in ecology. Traditionally, there was a focus on post-colonization effects such as predation, however, pre-colonization processes, such as habitat selection, are equally important determinants of community structure. In freshwater systems, the lethal effects of dominant predators (particularly fish) are well established, while the transition from permanent to temporary ponds is a defining characteristic. This transition produces distinct communities characterized by organisms with complex life cycles and plastic developmental strategies. This means that many organisms occupying habitat patches arrive there by the processes of dispersal and colonization. To better understand the processes regulating community assembly in temporary ponds, I conducted a series of mesocosm experiments that were colonized by natural populations of aquatic beetles and treefrogs. Hyla chrysoscelis selected habitats in which they minimized the risk of both desiccation and predation. Aquatic beetles selected habitats with more available resources, and their habitat preferences partitioned species among habitats based on the abundance of their preferred resource type. Furthermore, spatial context-dependent processes created patterns of beetle abundances distinct from what would be expected without any context-dependent processes. These results indicate that the variation in abiotic and biotic conditions in ponds creates landscapes that are heterogeneous mosaics of patches that vary in quality and have distinct communities that are assembled through several processes, beginning with colonization and habitat selection