Vegetation of Prairie Dog Colonies and Non-Colonized Shortgrass Prairie

Abstract

Black-tailed prairie dogs have declined by 98% in the past century. Due to continued declines, the U. S. Fish and Wildlife Service designated the species as a candidate for listing in 2000. Prairie dogs foster both plant and animal diversity, and their continued presence is a concern in the Great Plains. We compared vegetation structure and composition of black-tailed prairie dog (Cynomys ludovicianus Ord) colonies in southwest Kansas and southeast Colorado to non-colonized grassland in 1996, and 1997. Dominant species on prairie dog colonies were Bouteloua gracilis (H. B. K.) Lag. ex Griffiths (14% cover in 1996, 15% in 1997), Buchloe dactyloides (Nutt.) Engelm. (7% cover in 1996, 17% in 1997) and Aristida purpurea Nutt. (9% cover in 1996,16 % in 1997). Dominant vegetation at randomly selected non-colonized sites were Bouteloua curtipendula (Michx.) Torr. (16% cover in 1996,18% in 1997), Bouteloua gracilis (13% cover in 1996,17 % in 1997) and Buchloe dactyloides (5% cover in 1996, 5% in 1997). Non-colonized shortgrass sites were dominated by Bouteloua gracilis (23% cover in 1996, 41 % in 1997) and Buchloe dactyloides (8% cover in 1996,12% in 1997). Cover of grass was higher (P < 0.01) on random sites (44%) than on prairie dog colonies (31%) or shortgrass sites (33%) in 1996, whereas cover of forbs was higher (P < 0.01) on prairie dog colonies (18%) than on random sites (7%) or shortgrass sites (8%) that year. Vegetation height was greater (Q = 3.66) and visual obstruction was greater (Q = 3.39) on random sites (33.6 and 6.4 cm, respectively) than on prairie dog colonies (9.5 and 2.5 cm, respectively) in 1997, the only year these variables were measured. Percent bare ground did not differ (P > 0.05) among treatments either year. While components of the vegetation on prairie dog colonies differed from that found on non-colonized sites, the vegetation of prairie dog colonies was, nonetheless, characteristic of a shortgrass region. Prairie dogs undoubtably alter vegetation structure and composition in shortgrass prairie, and likely have a great influence on landscape heterogeneity, but our results suggest that shortgrass prairie is well adapted to the herbivory and soil disturbing activities of prairie dogs.

Spatiotemporal dynamics of black-tailed prairie dog colonies affected by plague

“…The Comanche complex occurs in a landscape with little topographic variation and predominantly loamy soils. Forbs, bare ground and purple threeawn are more abundant on prairie dog colonies, but both noncolonized and colonized areas are dominated by a warm-season shortgrass, blue grama (Winter et al 2002). In contrast, the Phillips County landscape includes greater topographic variability, a diversity of soil types, and off-colony vegetation with tallerstructure, cool-season grasses and sagebrush (Reading and Matchett 1997;Johnson-Nistler et al 2004).…”

“…Soils are predominantly clay loams, silt loams, and fine sandy loams (Woodyard et al 1973). Vegetation on prairie dog colonies is dominated by blue grama (Bouteloua gracilis), buffalograss (Buchloe dactyloides), and purple threeawn (Aristida purpurea), while noncolonized grassland is dominated by blue grama, sideoats grams (B. curtipendula), and buffalograss (Winter et al 2002). The National Grassland allotments that we studied are intermingled with private lands, which include rangeland, Conservation Reserve Program fields with taller-structure grasses, and cropland.…”

“…Weltzin et al 1997;Winter et al 2002;Johnson-Nistler et al 2004), but the time since colonization also determines vegetation changes. Studies in mixed-grass prairie of South Dakota (outside the plague zone) found that changes in species composition do not begin until 2 or more years after colonization, and that more than 15 years of prairie dog presence is required to induce the transition from grass dominance to a forb-shrub dominated community (Archer et al 1987;Coppock et al 1983;Whicker and Detling 1988;Detling 1998).…”

Books and Literature

“…The short-grass prairie is probably the ideal habitat for prairie-dog colonization and persistence (Winter et al 2002). Dominant grass species of this vegetation type include blue grama (Bouteloua gracilis) and buffalo grass (Buchloe dactyloides).…”

“…La pradera baja es quizá el hábitat ideal para la colonización y persistencia del perro de la pradera (Winter et al 2002). En la mayoría de estos entornos, no se requiere que los rumiantes pasten en la zona para que sobrevivan los perros llaneros, porque el pasto dominante es naturalmente bajo .…”