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Full-Text Articles in Life Sciences
Predator Presence And Size Variation Alters Community Structure Through Multiple Trophic Cascades, Robin Baker, Howard Whiteman Ph.D.
Predator Presence And Size Variation Alters Community Structure Through Multiple Trophic Cascades, Robin Baker, Howard Whiteman Ph.D.
Murray State Theses and Dissertations
Predation plays a crucial role in shaping community structure and can initiate trophic cascades that can alter abundances across adjacent trophic levels. Recent research has suggested that variation among individual predators may have stronger effects on ecological dynamics than previously appreciated. Intraspecific variation within predators could lead to differential levels of top-down control with implications for trophic cascade strength. In this experiment, we manipulated the body size variation of predatory mole salamanders (Ambystoma talpoideum) within experimental mesocosms and monitored a suite of abiotic and biotic response variables. We predicted that predator populations with increased body size variation would …
Omnivore Density Affects Community Structure Through Multiple Trophic Cascades, Donald J. Benkendorf
Omnivore Density Affects Community Structure Through Multiple Trophic Cascades, Donald J. Benkendorf
Murray State Theses and Dissertations
Omnivores can dampen trophic cascades by feeding at multiple trophic levels, yet few studies have evaluated how intraspecific variation influences the effect of omnivores on community structure. The Speckled Dace (Rhinichthys osculus) is an omnivorous cyprinid that consumes algae and invertebrates and is abundant throughout the western United States. I sought to identify the effects of size and size structure on top-down control by dace and learn how these effects scaled with density. Dace were manipulated in a mesocosm experiment and resulting changes in invertebrate and algal communities and measures of ecosystem function were monitored. Omnivores affected experimental …