soils, slope, aspect, and topography, but directly provides food, cover, shade, 

 nest sites, and other wildlife requisites. Also DNRC's vegetation baseline 

 study (Prodgers 1978) was in progress concurrently with the wildlife study, 

 and provided the opportunity for constant interaction between these two study 

 components. Methods used in vegetation sampling, classification, analysis, and 

 mapping have been presented in DNRC's final report on the vegetation baseline 

 study. 



Vegetation of the St u dy Area 



The study area is primarily a temperate grassland, or more precisely a 



mixed grass prairie (Weaver and Albertson 1956). A second major vegetation 



type in the area is the sagebrush-dominated cool semi-desert of Whittaker (1975). 



Other less abundant vegetation types occur in atypical sites. 



Several authors have mapped the vegetation of the area on rather small 

 scales, largely using existing data and some new samples or listing species. 



Kuchler (1964) has indicated that the area is potentially the blue grama- 

 needle-and-thread-western wheatgrass vegetation type.* Certainly these are the 

 three major species of the area. 



Ross and Hunter (1976) have identified three principal range sites for the 

 area: the silty range site having 25 cm - 35 cm (ten to fourteen inches) of 

 precipitation; the silty-clayey range site complex having 25 cm - 35 cm (ten 

 to fourteen inches) of precipitation; and to a lesser extent the badlands. The 

 three major climax dominants for the first two range sites dre western wheat- 

 grass (and thick spike w[ieatgrass) , little bluestem, and needle-and-thread. 

 The three principal increasers for these sites are blue grama, needle-and-thread 

 and thread-leaved sedge. 



Payne (1973) has indicated three major rangeland types for the area. The 

 southern portion of the study area is the Prairie County grassland, dominated 

 by needle-and-thread, thread-leaved sedge, and blue grama. The northwest por- 

 tion of the area is the central grassland, characterized by scattered sagebrush 

 and blue grama, needle-and-thread, and western wheatgrass. The northeastern 

 part of the study area is the northeastern grassland, distinguished by little 

 bluestem and also blue grama, needle-and-thread, and western wheatgrass. 



Habitat Categories 



On December 9, 1976, a preliminary classification of wildlife habitat 

 categories was prepared for use in the field, based upon the field experience 

 of DNRC personnel and several published classification schemes (U.S. D.I. 1976, 

 Stewart 1975, Mueggler and Handl 1974). Although the results of the DNRC veg- 

 etation community type classification did not become available until March, 1977, 

 they were found to agree very closely with the preliminary habitat categories. 

 Only eight categories were added to the December 9, 1976 list as a result of 

 this cluster analysis and three month's field experience with the habitat 



* Scientific names of plant species mentioned in the text are listed in 

 Appendix A. 



n 



