Effects of Management Practices on Terrestrial Vertebrate Diversity and Abundance in an Oak Savanna Ecosystem

摘要

Oak savanna and its associated species in the Midwest United States are being depleted and degraded. Oak savanna, a globally rare ecosystem, is dwindling because of hardwood encroachment, agricultural conversion and fire suppression. Disturbance is critical in an oak savanna ecosystem to maintain proper habitat structures for native species. Land management practices like herbicide applications, mechanical vegetation removal, and prescribed fire are all utilized to restore and maintain these early successional and native habitats in Northwest Ohio by subduing tree encroachment. Land management plays a key role in altering the structure of the landscape and subsequently the abundance and diversity of the wildlife in those areas.;To examine these relationships we surveyed 15 savannas in two preserves in Lucas County, Northwest Ohio. Point counts were conducted to observe avian and mammalian species day and night, May to October. We also used camera traps to assess larger wildlife within sites. Management data, provided by land managers, was aggregated per site via GIS. Our analysis, including linear mixed effects models and likelihood ratio tests yielded some significant results. Mixed effects models were run first and top fixed effects included in each of those models were analyzed using a likelihood ratio test to obtain a p-value for the relationship between variables.;Increasing mechanical management instances and duff depth correlated with and increase in total and avian abundance of observations (Likelihood ratio test, p-values <0.05). Increasing mechanical management instances was also correlated to a decrease in vegetation density (Likelihood ratio test, p-value <0.05) Increased Red-headed woodpecker abundance was correlated with increasing snag density (Likelihood ratio test, p-value <0.05). Increasing mammalian abundance of observations models were best predicted by the amount of coarse woody debris. Increasing mechanical management instances and duff depth correlated with and increase in total and avian abundance of observations (Likelihood ratio test, p-values <0.05).;Mechanical management repeatedly had relationships with response and environmental variables. Snag density, coarse woody debris, and vegetation density are all important structural features that relate to various vertebrate taxa. These findings contain important information for land managers in oak savanna ecosystems around the Midwest United States and the World.