Sigma Xi Poster Competition
Temperature and density-dependence interact to control leaf decomposition rate in mesocosm studies
Academic Level at Time of Presentation
Senior
Major
Earth and Environmental Science
2nd Student Academic Level at Time of Presentation
Senior
2nd Student Major
Fisheries/ Aquatic Biology
List all Project Mentors & Advisor(s)
Dr. Jessica Moon
Presentation Format
Poster Presentation
Abstract/Description
Climate warming has impacted environmental health, with more drastic increases in global temperatures predicted in the near future. Changes in biotic and abiotic factors caused by this warming can interact to create complex responses, which are difficult to predict. Amphibians play a significant role forested pond nutrient cycling by serving as inter-ecosystem subsidies; since their life history occurs both in terrestrial and aquatic environments, they transfer nutrients across the terrestrial-aquatic gradient. Paedomorphic salamanders function as keystone predators in these ecosystems, influencing nutrient cycling directly through predation and indirectly through trophic cascades. We studied the interactive effects of warming and a facultatively paedomorphic salamander species, Ambystoma talpoideum, on leaf decomposition (5g packs) by manipulating temperature (ambient, +1℃) and the density of salamanders; none (0 salamanders), low (10 salamanders, and high (15 salamanders) in a mesocosm experiment. Predicted values suggested that manipulating density will not have an effect on decomposition rates, but the warmed environments will increase decomposition due an increase in microbial activity. After tabulating the average difference in decomposition at three time periods (3 weeks, 16 weeks, 33 weeks), results suggest that manipulating the density of salamanders does not have an effect on decomposition rates, but warming does, with an increase in decomposition at higher temperatures. Heated mesocosms with no or low densities of paedomorphic salamanders had higher mass loss between the 3 week and second 16 week interval than non-heated low and no density mesocosms (1.8% and 2.9% respectively). In contrast, the high salamander density heated mesocosms had a lower mass loss than the not heated high density mesocosms between the first and second interval (3.9%). We predict this trend will continue when examining the 33 week interval, and in general, leaf packs with a longer residence time within the mesocosms.
Spring Scholars Week 2025
Sigma Xi Poster Competition
Temperature and density-dependence interact to control leaf decomposition rate in mesocosm studies
Climate warming has impacted environmental health, with more drastic increases in global temperatures predicted in the near future. Changes in biotic and abiotic factors caused by this warming can interact to create complex responses, which are difficult to predict. Amphibians play a significant role forested pond nutrient cycling by serving as inter-ecosystem subsidies; since their life history occurs both in terrestrial and aquatic environments, they transfer nutrients across the terrestrial-aquatic gradient. Paedomorphic salamanders function as keystone predators in these ecosystems, influencing nutrient cycling directly through predation and indirectly through trophic cascades. We studied the interactive effects of warming and a facultatively paedomorphic salamander species, Ambystoma talpoideum, on leaf decomposition (5g packs) by manipulating temperature (ambient, +1℃) and the density of salamanders; none (0 salamanders), low (10 salamanders, and high (15 salamanders) in a mesocosm experiment. Predicted values suggested that manipulating density will not have an effect on decomposition rates, but the warmed environments will increase decomposition due an increase in microbial activity. After tabulating the average difference in decomposition at three time periods (3 weeks, 16 weeks, 33 weeks), results suggest that manipulating the density of salamanders does not have an effect on decomposition rates, but warming does, with an increase in decomposition at higher temperatures. Heated mesocosms with no or low densities of paedomorphic salamanders had higher mass loss between the 3 week and second 16 week interval than non-heated low and no density mesocosms (1.8% and 2.9% respectively). In contrast, the high salamander density heated mesocosms had a lower mass loss than the not heated high density mesocosms between the first and second interval (3.9%). We predict this trend will continue when examining the 33 week interval, and in general, leaf packs with a longer residence time within the mesocosms.