Mj. Brady et Na. Slade, Diversity of a grassland rodent community at varying temporal scales: The role of ecologically dominant species, J MAMMAL, 82(4), 2001, pp. 974-983
Using a long-term data set (1989-1999), we examined how changes in abundanc
e of 2 ecologically dominant species, prairie voles (Microtus ochrogaster)
and hispid cotton rats (Sigmodon hispidus), affected the local diversity of
a grassland rodent community at varying temporal scales. Species richness
was associated positively with long-term fluctuations in the abundance of p
rairie voles and cotton rats over the 10-year period. Although increased vo
le densities consistently had a significantly negative effect on total comm
unity evenness, evenness of other community members was unaffected by fluct
uating vole densities. Presence of cotton rats negatively affected both the
relative abundance of other community members and the species richness dur
ing the years of high density (1991-1995), but did not exhibit longer-term
influences. Thus, despite their numerical dominance, changes in prairie vol
e abundance had little ecological effect on the rest of the community, wher
eas the influence of cotton rats was density- and temporally dependent.