EAGER: A novel investigation of population and community temporal trajectories leveraging experimental disturbances from Konza Prairie Long-Term Ecological Research Network site

Denison University, Granville OH

Investigators

Abstract

Species do not live in a constant environment. Rather, each species exhibits growth, reproduction, mortality, and movement patterns that are the result of changing conditions. Natural and human-driven disturbances can have substantial short-term or long-term effects on species populations, and in turn, on the overall biodiversity within a system. Short-term disturbances, known as “pulse disturbances”, can have rapid positive or negative impacts on species populations, followed by periods of recovery. Long-term disturbances, known as “press disturbances”, are chronic or ongoing changes to the environment that are predicted to cause directional (increased or decreased) changes in species populations and overall biodiversity. To fully understand the effects of disturbance on biodiversity, it is necessary to distinguish the patterns of species that are entering and exiting the community through time. Such a method will allow identification of species that are becoming locally uprooted, establishing, or exhibiting recurrent or random occurrence through time. This study will use long-term ecological experiments on the effects of fire (pulse) and grazing (press) disturbance treatments from the well-established Konza Prairie Long-Term Ecological Research (LTER) network site across plants, insects, birds, and small mammals. The research will support undergraduate research and education activities at a small liberal arts college and findings will be shared through open access publication. This work investigates a novel classification methodology for sequential species presence and absence (incidence) patterns and uses long-term control-experiment comparisons with 15 or more years of data to test the level of ecological disturbance needed for species to “switch” their incidence. The work will be repeated across two main treatments representing pulse (fire) and press (grazing) disturbance types, and will compare the findings across plant and animal (insect, bird, small mammal) taxonomic groups. The research will generate estimates of changes in population abundance, the proportion of years present, and the incidence classification for each species population and compare among the controls and disturbance treatments. Species-level data will inform understanding of population abundance, persistence, and incidence trends, the co-variation or decoupling of these three measures, and inform how pulse and press disturbance regimes impact populations and ultimately community structure and biodiversity. The incidence classification methodology is not system- or taxa- specific and this research would provide a first test of the new approach in disturbed systems that has the potential to uncover new trends not identified using abundance or persistence methodologies alone. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.