Biodiversity is enhanced by sequential resource utilization and environmental fluctuations via emergent temporal niches

Blox Bloxham, Hyunseok Lee, Jeff Gore

Abstract: Author summary Natural ecosystems feature huge numbers of coexisting species, and understanding what dynamics arise from this complexity is a core focus of ecology. Here, we study these dynamics from the perspective of resource competition. In many ecosystems, resources (i.e. food) become available in discrete pulses (for example, at the start of a growing season) and are depleted between pulses. When multiple resources are available, some resources are inevitably depleted faster than others. When species consume resources one at a time but with preference orders that differ between species, sequential resource depletions create rich patterns of species sometimes being in direct competition and sometimes competing for separate resources. We explore these rich dynamics and show that when fluctuations in the relative supply of each resource varies from one pulse to another so does the resource depletion order. These variations allow many more species than resources to coexist, violating the canonical “competitive exclusion principle”. We develop a framework of temporal niches that illuminates the competitive dynamics within these communities and accurately predicts which species will survive. The predictive power of these temporal niches represents a significant advance in our ability to understand complex communities from the perspective of resource competition.