Small Mammal Populations In Switchgrass Managed for Biomass, Cool-Season Grass-Legume Mixed Hay, and Corn Fields In Kentucky.

Switchgrass (Panicum virgatum L.), a native warm-season grass often used in wildlife habitat plantings, has the potential as a bioenergy crop. However, bioenergy switchgrass are typically monoculture stands, harvested annually, and managed for maximum yield, which may impact the wildlife habitat quality. Our objective is to investigate small mammal populations in bioenergy switchgrass stands compared to cool-season grass-legume mixed hay and corn (Zea mays L.) fields (no-till and conventional till systems). In 2009, 4 three-night trapping sessions were conducted at 4 locations in Kentucky using Sherman livetraps. Trapping sessions occurred in April/May before first hay harvest (spring), July/August (mid-summer), September/October before switchgrass and corn harvest (late-summer), and December after harvest (fall). Small mammal relative abundance was calculated using a capture per unit effort (CPUE) index (per 100 trapnights). Six mammalian species were recorded: Peromyscus leucopus, Peromycus maniculatus, Mus musculus, Blarina brevicauda, Microtus orchrogastor, and Microtus pennsylvanicus. Microtus species were classified as Microtus spp. due to difficulties in field identification. All species were recorded in switchgrass and hayfields, while B. brevicauda and Microtus spp. were not found in corn. Chronological CPUE indexes were 5.32, 18.52, 30.05, and 18.61 in switchgrass; 3.06, 22.45, 11.11, and 3.06 in corn; and 2.45, 2.55, 3.79, and 4.72 in hay. Relative abundance in switchgrass and corn were higher than hay in mid-summer, switchgrass was highest in late-summer, and switchgrass was highest at a significance of P=0.10 but not significant at P=0.05 in fall. Relative abundance of no-till corn was higher than conventional till corn during all trapping sessions except spring. In conclusion, switchgrass and no-till corn fields are viable habitat for some small mammal species; however, switchgrass provides habitat for a larger number of species compared to corn. Hay fields were poor habitat for small mammals; possibly due to high disturbance resulting from multiple harvests during the growing season.