Biodiversity is often emphasized at the species level where each species is assigned a mean functional trait value. However, populations within a species, and individuals within a population, often exhibit considerable intraspecific functional variation. Therefore, instead of focusing on species’ mean trait values, we must incorporate intraspecific variation when considering species’ ecological roles and conservation values. The primary objective of this study was to determine the effects of variation in body size (a functional trait in many aquatic taxa) in an apex predator on ecosystem functioning. We sought to characterize trophic cascades initiated by larval populations of Ambystoma jeffersonianum that varied in size structure based on diversity of maternal lines (i.e., sibship diversity) by quantifying the effect on larval salamanders, benthic macroinvertebrates, zooplankton, phytoplankton, and periphyton, as well as leaf-litter decomposition rates and release of soluble nutrients in cattle tank mesocosms. Although sibship diversity did not lead to populations of variable body size, it was positively related to larval density and survival to metamorphosis in A. jeffersonianum. Sibship diversity did not affect growth rates or dates of metamorphosis for A. jeffersonianum, nor did it have any significant effects on invertebrate communities and ecosystem function. This research emphasizes the importance of considering the effect of sibship diversity on predator density for intraspecific variation and the subsequent long-term effects on ecosystem function.
","abstract_html":"<p>Biodiversity is often emphasized at the species level where each species is assigned a mean functional trait value. However, populations within a species, and individuals within a population, often exhibit considerable intraspecific functional variation. Therefore, instead of focusing on species’ mean trait values, we must incorporate intraspecific variation when considering species’ ecological roles and conservation values. The primary objective of this study was to determine the effects of variation in body size (a functional trait in many aquatic taxa) in an apex predator on ecosystem functioning. We sought to characterize trophic cascades initiated by larval populations of Ambystoma jeffersonianum that varied in size structure based on diversity of maternal lines (i.e., sibship diversity) by quantifying the effect on larval salamanders, benthic macroinvertebrates, zooplankton, phytoplankton, and periphyton, as well as leaf-litter decomposition rates and release of soluble nutrients in cattle tank mesocosms. Although sibship diversity did not lead to populations of variable body size, it was positively related to larval density and survival to metamorphosis in A. jeffersonianum. Sibship diversity did not affect growth rates or dates of metamorphosis for A. jeffersonianum, nor did it have any significant effects on invertebrate communities and ecosystem function. This research emphasizes the importance of considering the effect of sibship diversity on predator density for intraspecific variation and the subsequent long-term effects on ecosystem function.</p>","abstract_has_math":false,"creators":["Smith, David Samuel"],"institution":"Eastern Kentucky University","degree_name":"Master of Science (MS)","degree_level":"Master's","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-01-01T08:00:00Z","date_published":"2019-01-01T08:00:00Z","updated_at":"2026-07-24T02:15:47Z","subjects":["intraspecific variation","metamorphosis","predation","sibship diversity","trophic cascade","Terrestrial and Aquatic Ecology"],"languages":[],"rights":["Copyright 2019 David Samuel Smith"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://encompass.eku.edu/etd/600","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Smith, David Samuel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Encompass Digital Archive, Eastern Kentucky University"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Master's"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Eastern Kentucky University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["intraspecific variation","metamorphosis","predation","sibship diversity","trophic cascade","Terrestrial and Aquatic Ecology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2019 David Samuel Smith"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://encompass.eku.edu/etd/600"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Biodiversity is often emphasized at the species level where each species is assigned a mean functional trait value. However, populations within a species, and individuals within a population, often exhibit considerable intraspecific functional variation. Therefore, instead of focusing on species’ mean trait values, we must incorporate intraspecific variation when considering species’ ecological roles and conservation values. The primary objective of this study was to determine the effects of variation in body size (a functional trait in many aquatic taxa) in an apex predator on ecosystem functioning. We sought to characterize trophic cascades initiated by larval populations of Ambystoma jeffersonianum that varied in size structure based on diversity of maternal lines (i.e., sibship diversity) by quantifying the effect on larval salamanders, benthic macroinvertebrates, zooplankton, phytoplankton, and periphyton, as well as leaf-litter decomposition rates and release of soluble nutrients in cattle tank mesocosms. Although sibship diversity did not lead to populations of variable body size, it was positively related to larval density and survival to metamorphosis in A. jeffersonianum. Sibship diversity did not affect growth rates or dates of metamorphosis for A. jeffersonianum, nor did it have any significant effects on invertebrate communities and ecosystem function. This research emphasizes the importance of considering the effect of sibship diversity on predator density for intraspecific variation and the subsequent long-term effects on ecosystem function.
"]},{"key":"dc:format","label":"Dc Format","values":["application/PDF"]},{"key":"dc:source","label":"Dc Source","values":["Encompass Digital Archive: Online Theses and Dissertations"]},{"key":"dc:title","label":"Title","values":["Ecosystem Functional Consequences Of Body Size Variation In An Apex Predator (Ambystoma jeffersonianum)"]}]}],"canonical_facts":{"dc:creator":["Smith, David Samuel"],"dc:description.abstract":["Biodiversity is often emphasized at the species level where each species is assigned a mean functional trait value. However, populations within a species, and individuals within a population, often exhibit considerable intraspecific functional variation. Therefore, instead of focusing on species’ mean trait values, we must incorporate intraspecific variation when considering species’ ecological roles and conservation values. The primary objective of this study was to determine the effects of variation in body size (a functional trait in many aquatic taxa) in an apex predator on ecosystem functioning. We sought to characterize trophic cascades initiated by larval populations of Ambystoma jeffersonianum that varied in size structure based on diversity of maternal lines (i.e., sibship diversity) by quantifying the effect on larval salamanders, benthic macroinvertebrates, zooplankton, phytoplankton, and periphyton, as well as leaf-litter decomposition rates and release of soluble nutrients in cattle tank mesocosms. Although sibship diversity did not lead to populations of variable body size, it was positively related to larval density and survival to metamorphosis in A. jeffersonianum. Sibship diversity did not affect growth rates or dates of metamorphosis for A. jeffersonianum, nor did it have any significant effects on invertebrate communities and ecosystem function. This research emphasizes the importance of considering the effect of sibship diversity on predator density for intraspecific variation and the subsequent long-term effects on ecosystem function.
"],"dc:format":["application/PDF"],"dc:identifier":["https://encompass.eku.edu/etd/600"],"dc:publisher":["Encompass Digital Archive, Eastern Kentucky University"],"dc:rights":["Copyright 2019 David Samuel Smith"],"dc:source":["Encompass Digital Archive: Online Theses and Dissertations"],"dc:subject":["intraspecific variation","metamorphosis","predation","sibship diversity","trophic cascade","Terrestrial and Aquatic Ecology"],"dc:title":["Ecosystem Functional Consequences Of Body Size Variation In An Apex Predator (Ambystoma jeffersonianum)"],"dc:type":["Master Thesis"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Master's"],"thesis:degree_name":["Master of Science (MS)"],"thesis:institution_name":["Eastern Kentucky University"]},"updated_at":"2026-07-24T02:15:47Z"}