title: Plant-herbivore interactions in a North American mixed-grass prairie : I. Effects of black-tailed prairie dogs on intraseasonal aboveground plant biomass and nutrient dynamics and plant species diversity.
abstract: Research was conducted to determine the effects of a native, sedentary rodent of North American grasslands, the black-tailed prairie dog (Cynomys ludovicianus), on seasonal aboveground plant biomass and nutrient dynamics and plant species diversity. The study was done on a northern mixed-grass prairie site at wind Cave National Park, South Dakota.Peak live plant biomass was greatest (190 g/m2) on the uncolonized part of the study area and least (95 g/m2) on a part of the prairie dog town colonized for 3 to 8 y. Peak live plant biomass (170 g/m2) of the oldest portion of the prairie dog town (colonized >26 y) was not significantly different from that of uncolonized prairie. However, where-as graminoids composed >85% of the total biomass of the latter area, forbs and dwarf shrubs (Artemisia frigida) were >95% of the total of the former. Both standing-dead plant biomass and litter declined markedly as time since colonization increased. Total plant species diversity (H) was greatest in the young prairie dog town (colonized for 3 to 8 y).Nitrogen concentration of plant shoots varied significantly as a function of time since colonization. Shoot-nitrogen was lowest in plants from the uncolonized site and greatest in plants collected from the longest-colonized areas of the prairie dog town. Shoot-nitrogen declined significantly over the growing season and tended to be higher in C3graminoids than in C4graminoids. In vitro digestible dry matter showed similar trends; the differences between C3and C4digestibilities were greatest during the last half of the growing season.We suggest that prairie dog-induced changes in plant biomass, plant species diversity, plant nutrient content, and forage digestibility may lead to further alterations of nutrient cycling and trophic dynamics in this mixed-grass prairie ecosystem.
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, 80523, Fort Collins, CO, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Coppock
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, 80523, Fort Collins, CO, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Detling
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, 80523, Fort Collins, CO, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Ellis
authors.affiliation: Environmental Resources Section, Environmental Science Division, Oak Ridge National Laboratories, 37830, Oak Ridge, TN, USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Dyer