with Gap Light Analyzer version 2 (GLA, Frazer, Canham, & Lertzman 1999), which calculated percent of open sky and leaf area index of the canopy overstory. To measure ground vegetation cover, ten 1m2 subplots, arranged in two rows of five, were established in the center of each of the 12 plots in August 2010 (Palmer et al., unpublished data). Percent ground cover was determined by trained observers who visually estimated the percentage of vascular plant cover on a scale of 1 to 100%. Plants were identified to genus and species when known and classified as woody or herbaceous (Palmer et al., unpublished data). I used total precipitation (mm) from the winter and spring seasons prior to small mammal trapping each year as an approximation of aboveground net primary productivity (ANPP). Precipitation was collected from rain gauges at the Open Lowland Station (41.25° N, 74.10° W) in BRF. The positive relationship between ANPP and precipitation has been well documented (Rosenzweig 1968; Walter 1971; Sala et al. 1988). I used precipitation from the prior seasons because small mammal populations respond to winter precipitation with a three- month lag time (Bradley et al. 2006). Oak mast was collected annually from mid-September to early October of each year. Sampling was conducted weekly at 15 locations in BRF with predetermined transects (Brady 1994), and acorn mast density was quantified using traditional methods (Eckert, Marquis, & Roach 1976). Samples were extrapolated to determine the total annual acorn crop per hectare in BRF. Soil temperature, soil moisture, air temperature, Environmental Data Analysis – leaf fall, ground vegetation cover, coarse woody debris, and canopy openness
with Gap Light Analyzer version 2 (GLA, Frazer, Canham, & Lertzman 1999), which calculated percent of open sky and leaf area index of the canopy overstory. To measure ground vegetation cover, ten 1m2 subplots, arranged in two rows of five, were established in the center of each of the 12 plots in August 2010 (Palmer et al., unpublished data). Percent ground cover was determined by trained observers who visually estimated the percentage of vascular plant cover on a scale of 1 to 100%. Plants were identified to genus and species when known and classified as woody or herbaceous (Palmer et al., unpublished data). I used total precipitation (mm) from the winter and spring seasons prior to small mammal trapping each year as an approximation of aboveground net primary productivity (ANPP). Precipitation was collected from rain gauges at the Open Lowland Station (41.25° N, 74.10° W) in BRF. The positive relationship between ANPP and precipitation has been well documented (Rosenzweig 1968; Walter 1971; Sala et al. 1988). I used precipitation from the prior seasons because small mammal populations respond to winter precipitation with a three- month lag time (Bradley et al. 2006). Oak mast was collected annually from mid-September to early October of each year. Sampling was conducted weekly at 15 locations in BRF with predetermined transects (Brady 1994), and acorn mast density was quantified using traditional methods (Eckert, Marquis, & Roach 1976). Samples were extrapolated to determine the total annual acorn crop per hectare in BRF. Environmental Data Analysis – Soil temperature, soil moisture, air temperature, leaf fall, ground vegetation cover, coarse woody debris, and canopy openness