A multi-spatial scale analysis of factors affecting browsing damage by white-tailed deer (Odocoileus virginianus) in cross timbers woodlands of Kansas and Oklahoma
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Abstract
The amount of damage that herbivores impose on plants varies greatly in space, yet ecologists’ ability to predict where herbivores will most damage plants remains poor. White-tailed deer (Odocoileus virginianus) are abundant generalist herbivores in eastern North America. In the Cross Timbers ecosystem of Kansas and Oklahoma, high deer densities impact tree regeneration through selective browsing. This study investigate factors influencing deer browse intensity on post oak (Quercus stellata) and blackjack oak (Quercus marilandica) seedlings across nested spatial scales: landscape, home range, and plant neighborhood. I explored the relative importance of these scales in determining browsing intensity and assess which combination of variables, regardless of scale, best predicts browsing intensity. Additionally, I examined whether incorporating environmental context enhances predictions beyond those based solely on oak seedling species identity, individual size, and local hunting pressures. Both field data and remotely sensed data were used to quantify potential explanatory variables at the three spatial scales, followed by model selection using Akaike's Information Criterion corrected for small sample sizes (AICc). Results indicate a decrease in predictive ability as spatial scales increases. At the home range scale, habitat heterogeneity and distance to road were the most influential factors in determining browsing pressure on oak seedlings. At the neighborhood scale, greater browse damage (associational susceptibility) with preferred and diverse woody neighbors and reduced browse damage (neighbor contrast defense) with more surrounding forbs were observed. This study suggests that deer browsing damage to tree seedlings is strongly influenced by environmental context at local spatial scales.

