Small-mammal regulation of vegetation structure in a temperate savanna
Authors: J. F. Weltzin, S. Archer, and R. K. Heitschmidt
Summary of Methods: Weltzin et al. measured the characteristics of honey mesquite populations on and off two prairie dog colonies to determine if prairie dogs, and other species associated with their colonies, limit the encroachment of this shrub on grasslands. On prairie dog colonies, honey mesquite seed and pod disappearance was greater, emergence and survival of seedlings was lower, and the survival of sapling sized trees was also lower. The density of mesquite plants was greater on prairie dog colonies, but due to continued defoliation, all plants were small and short unlike the few, large, older shrubs that were found on sites where prairie dogs were not present. Prairie dogs and ant species associated with their colonies reduce the seed dispersal and growth of honey mesquite shrubs. This helps to maintain the grassland plant community, however, mesquite can quickly dominate the plant community on prairie dog towns, especially when upon the removal of prairie dogs.
Article Summary / Main Points: None
Article Review Type: Refereed
Article Type: Experimental Research
Keywords: black-tailed prairie dogs, cynomys ludovicianus, shrub encroachment, honey mesquite, prosopis glandulosa, ants, seed disappearance, seedling establishment, succession, tree-grass dynamics
Annotation: Cattle were also grazed year-round at a moderate stocking rate at one of the colonies where measurements were taken during this study. The authors did not mention any differences in measurements due to the presence of cattle.