Climate change will elicit various species responses as it causes habitats to change. Species with limited dispersal must respond to these changes “in place”, yet some biogeographical hypotheses indicate isolated and less abundant populations experience reduced gene flow and genetic diversity that may limit phenotypic plasticity, contrasting with evidence suggesting more variable habitats select for increased plasticity in peripheral populations. To gain insight into associations between range position and intensity of plasticity, mesocosm experiments were done to assess plasticity in larval growth, size at, and time to, metamorphosis, and survivorship in larval Ambystoma jeffersonianum salamanders from geographically core and peripheral populations. These populations were exposed to longer and shorter hydroperiods reflecting current and predicted future air temperatures, respectively, consistent with the A2 Climate Scenario for 2050. Growth rates and times to metamorphosis of edge populations were faster, yet larvae metamorphosed at smaller sizes. Populations experiencing future climate treatments were smaller and exhibited faster times to metamorphosis, and had higher survivorship than populations exposed to current climate treatments. In 2020, metamorphs were smaller on average than in 2021. Though these differences indicate plasticity in some larval traits, no differences in the magnitude of plasticity were observed between populations or years, tentatively suggesting populations may exhibit similar levels of genetic diversity, or that habitats may not be far enough away or differ enough in stochasticity between collection sites to detect variation in plasticity. These results improve our understanding of population-level differences in responses to environmental change, and the potential needs to incorporate population-level variation in future conservation and management efforts in the face of global climate change.
","abstract_html":"<p>Climate change will elicit various species responses as it causes habitats to change. Species with limited dispersal must respond to these changes “in place”, yet some biogeographical hypotheses indicate isolated and less abundant populations experience reduced gene flow and genetic diversity that may limit phenotypic plasticity, contrasting with evidence suggesting more variable habitats select for increased plasticity in peripheral populations. To gain insight into associations between range position and intensity of plasticity, mesocosm experiments were done to assess plasticity in larval growth, size at, and time to, metamorphosis, and survivorship in larval Ambystoma jeffersonianum salamanders from geographically core and peripheral populations. These populations were exposed to longer and shorter hydroperiods reflecting current and predicted future air temperatures, respectively, consistent with the A2 Climate Scenario for 2050. Growth rates and times to metamorphosis of edge populations were faster, yet larvae metamorphosed at smaller sizes. Populations experiencing future climate treatments were smaller and exhibited faster times to metamorphosis, and had higher survivorship than populations exposed to current climate treatments. In 2020, metamorphs were smaller on average than in 2021. Though these differences indicate plasticity in some larval traits, no differences in the magnitude of plasticity were observed between populations or years, tentatively suggesting populations may exhibit similar levels of genetic diversity, or that habitats may not be far enough away or differ enough in stochasticity between collection sites to detect variation in plasticity. These results improve our understanding of population-level differences in responses to environmental change, and the potential needs to incorporate population-level variation in future conservation and management efforts in the face of global climate change. </p>","abstract_has_math":false,"creators":["Devine, Aaron"],"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":2022,"date_issued":"2022-01-01T08:00:00Z","date_published":"2022-01-01T08:00:00Z","updated_at":"2026-07-24T02:15:53Z","subjects":["Climate","Terrestrial and Aquatic Ecology"],"languages":[],"rights":["Copyright 2022 Aaron Devine"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://encompass.eku.edu/etd/705","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Devine, Aaron"]}]},{"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":["Climate","Terrestrial and Aquatic Ecology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2022 Aaron Devine"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://encompass.eku.edu/etd/705"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Climate change will elicit various species responses as it causes habitats to change. Species with limited dispersal must respond to these changes “in place”, yet some biogeographical hypotheses indicate isolated and less abundant populations experience reduced gene flow and genetic diversity that may limit phenotypic plasticity, contrasting with evidence suggesting more variable habitats select for increased plasticity in peripheral populations. To gain insight into associations between range position and intensity of plasticity, mesocosm experiments were done to assess plasticity in larval growth, size at, and time to, metamorphosis, and survivorship in larval Ambystoma jeffersonianum salamanders from geographically core and peripheral populations. These populations were exposed to longer and shorter hydroperiods reflecting current and predicted future air temperatures, respectively, consistent with the A2 Climate Scenario for 2050. Growth rates and times to metamorphosis of edge populations were faster, yet larvae metamorphosed at smaller sizes. Populations experiencing future climate treatments were smaller and exhibited faster times to metamorphosis, and had higher survivorship than populations exposed to current climate treatments. In 2020, metamorphs were smaller on average than in 2021. Though these differences indicate plasticity in some larval traits, no differences in the magnitude of plasticity were observed between populations or years, tentatively suggesting populations may exhibit similar levels of genetic diversity, or that habitats may not be far enough away or differ enough in stochasticity between collection sites to detect variation in plasticity. These results improve our understanding of population-level differences in responses to environmental change, and the potential needs to incorporate population-level variation in future conservation and management efforts in the face of global climate change.
"]},{"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":["Phenotypic Plasticity of Geographically Central and Peripheral Populations of Jefferson Salamanders (Ambystoma jeffersonianum) in Response to Simulated Climate Change"]}]}],"canonical_facts":{"dc:creator":["Devine, Aaron"],"dc:description.abstract":["Climate change will elicit various species responses as it causes habitats to change. Species with limited dispersal must respond to these changes “in place”, yet some biogeographical hypotheses indicate isolated and less abundant populations experience reduced gene flow and genetic diversity that may limit phenotypic plasticity, contrasting with evidence suggesting more variable habitats select for increased plasticity in peripheral populations. To gain insight into associations between range position and intensity of plasticity, mesocosm experiments were done to assess plasticity in larval growth, size at, and time to, metamorphosis, and survivorship in larval Ambystoma jeffersonianum salamanders from geographically core and peripheral populations. These populations were exposed to longer and shorter hydroperiods reflecting current and predicted future air temperatures, respectively, consistent with the A2 Climate Scenario for 2050. Growth rates and times to metamorphosis of edge populations were faster, yet larvae metamorphosed at smaller sizes. Populations experiencing future climate treatments were smaller and exhibited faster times to metamorphosis, and had higher survivorship than populations exposed to current climate treatments. In 2020, metamorphs were smaller on average than in 2021. Though these differences indicate plasticity in some larval traits, no differences in the magnitude of plasticity were observed between populations or years, tentatively suggesting populations may exhibit similar levels of genetic diversity, or that habitats may not be far enough away or differ enough in stochasticity between collection sites to detect variation in plasticity. These results improve our understanding of population-level differences in responses to environmental change, and the potential needs to incorporate population-level variation in future conservation and management efforts in the face of global climate change.
"],"dc:format":["application/PDF"],"dc:identifier":["https://encompass.eku.edu/etd/705"],"dc:publisher":["Encompass Digital Archive, Eastern Kentucky University"],"dc:rights":["Copyright 2022 Aaron Devine"],"dc:source":["Encompass Digital Archive: Online Theses and Dissertations"],"dc:subject":["Climate","Terrestrial and Aquatic Ecology"],"dc:title":["Phenotypic Plasticity of Geographically Central and Peripheral Populations of Jefferson Salamanders (Ambystoma jeffersonianum) in Response to Simulated Climate Change"],"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":"2026-07-24T02:15:53Z"}