Mammal diversity in different aged plots in northern Lower Michigan.

Abstract

Small mammal communities were examined at five burn plots at the University of Michigan Biological Station in Pellston, northern Lower Michigan. Burn years of plots were 1917, 1936, 1954, 1980, and 1998. Aspen dominated canopy coverage in older plots, with small and immature vegetation found in the younger plots. We noted the effects of ecological succession on community composition. Vegetation structure and coarse woody debris were examined at each plot to observe possible relationships with mammal distribution. There were significant differences among plots in the number of Peromyscus leucopus caught (XX=17.19, df=4, 0.001<p<0.01): the number of adults, sub adults and juveniles (XX=20.2, df=8, 0.001<p<0.01): the number of scrotal vs. abdominal males (XX=11.32, df=4, 0.02<p<0.05): and the number of females with tiny vs. enlarged nipples (XX=11.185, df=4, 0.02<p<0.05). The percent of males with abdominal testes was negatively correlated with the amount of coarse woody debris (CWD) (Rs=-0.9, p=0.037, N=5). CWD is a primary factor affecting distribution of small mammals, as reproductive and heavier individuals are found in areas with the greatest amount. Vegetation density and canopy coverage of plots was not related to mammal distribution.