A Confluence of Invasion, Behavioral, and Theoretical Ecology: What Drives Ephemeral Metacommunity Re-assembly? Dissertation

thesis or dissertation chair

fiu authors

  • Blanchard, Jesse Ryan

abstract

  • Metacommunity theory has been particularly useful in understanding the way spatially structured communities assemble. Both niche and neutral processes are known to influence metacommunity assembly, and the relative influence of each depends on the level of dispersal-limitation. Contemporary trait-based analyses of metacommunity assembly have enhanced our understanding of these processes. Of the traits investigated, individual personalities have received the least attention, but have been suggested to be drivers of metacommunity assembly model parameters, such as dispersal tendencies and patch density. I address this topic from three angles, three chapters, in this dissertation. First, I used a three-year field survey of fish metacommunity assembly in Everglades National Park to investigate the influence of dispersal-limitation on trait-based metacommunity assembly, asking which traits were important under different levels of dispersal-limitation. I found that the relative influence of traits and local environmental factors decreased, and the influence of regional factors increased with increasing dispersal-limitation. The Rocky Glades has recently been invaded by a micropiscivore with many novel traits, the African Jewelfish. In the second chapter I used my field data to ask what influence this invader has on metacommunity assembly. Overall, African Jewelfish abundance was the third most influential factor in driving assembly. I also used data, which were previously collected by collaborators, from three years prior and two years following the invasion to observe shifts in assembly rules. Assembly became significantly more aggregative immediately following the invasion, a condition which persisted more than a decade later. All previous studies asking the same question, found the same result: invasive introductions correspond with increased species aggregation. This may be a consistent, taxa-independent signal of truly invasive species that can be detected early in the invasion process, making it a potentially useful management tool after further empirical review. In the final chapter, I investigate the potential influence of individual personalities on a metapopulation’s structure. To do this, I used a behavioral individual-based model to explore the influence of sociability, an individual’s propensity to associate with conspecifics, on metapopulation structure at ecologically relevant spatiotemporal scales. I found that individual sociability can significant influence key metapopulation parameters such as dispersal distance and patch density but may not influence landscape occupation. Chapter three concludes with new hypothesis to be evaluated by future field studies. Overall, this dissertation demonstrates the relative roles of invasions, species traits, and individual personalities on metacommunity assembly processes.

publication date

  • March 30, 2018

Digital Object Identifier (DOI)