Dissertation Research: Evaluation of a Hypothetical Model of Local Community Assembly in a Temporally Dynamic, Species Rich Neotropical River

Texas A&M Agrilife Research, College Station TX

Investigators

Abstract

Evaluation of a hypothetical model of local community assembly in a temporally dynamic, species rich neotropical river DEB 0107456; PI: Kirk O. Winemiller, Co-PI: D. Albrey Arrington Abstract Results from this study will further our understanding of biological community structure and formation. Natural communities are affected by characteristics of the environment and interactions among constituent organisms. Understanding the relative importance of these factors and their interactions is highly relevant to the preservation of healthy communities and restoration of damaged communities. Our study investigates the temporal and spatial dynamics of community assembly in a tropical floodplain river with very high biodiversity. Our previous work has demonstrated consistent patterns in local fish and invertebrate communities that depend on physical habitat complexity and seasonal dynamics. In this study, we will conduct field experiments that manipulate habitat patches with variable physical complexity to evaluate the relative importance of physical and biological factors for species colonization. Our experimental design also will allow us to determine the relative importance of stochastic and deterministic processes in the formation of local communities. In other words, we hope to determine whether or not local biological communities are simply collections of individuals and species that happened to find an available habitat patch, or if community membership results from species interactions such as competition and predation. Based on previous descriptive research, we hypothesize that nonrandom processes result in highly patterned fish and invertebrate communities during the low-water period, and that colonization of local habitats becomes more random during the annual flood period.