Perhaps the most striking feature found in comparing the 1979 data with 

 earlier data is the increase in litter, particularly in exclosures with a 

 significant amount of Agropyron smithii . Table 13 summarizes this increase. 



Most of the dramatic increases in litter are linked to A gropyron smithii 

 This species has now changed the composition of the Bogr/Agsm and Stco/Bogr 

 exclosures. Litter accumulation may also become a problem. It is suggested 

 that some exclosures be opened to grazing following clipping in 1980. (This 

 topic is further discussed later in this report.) 



Frequency and Coverage 



Plant coverage was generally down and the amount of bare ground higher 

 than in 1978. Annuals in particular showed a marked decline, probably as a 

 result of the drier conditions experienced in 1979 (Table 14). 



Some other changes are worth noting. Agropyron sir.ithii was virtually 

 absent from the Stco/Bogr-Cafi exclosures in 1978 and increased to an average 

 10% coverage in 1979. Litter also increased significantly. In the Bogr/Agsm 

 exclosure, Agropyron smithi i coverage diminished while coverage of litter and 

 bare ground increased substantially. Litter increased greatly in the Agsm/Bogr 

 exclosure also. Plant coverage was greatly reduced in the Dist-Agsm exclo- 

 sure. 



The Bogr exclosure is apparently the site of a one-time prairie dog 

 town. Patches of Agropyron smithii are found in this exclosure; the dis- 

 tribution appears to be contagious. These patches appear to be expanding 

 under exclosure conditions. 



It is suggested that the Bogr, Dist-Agsm. Stco/Bogr-Cafi, and Bogr/Agsm 

 exclosures be left open during 1980 following clipping to allow grazing. 

 These exclosures should then be monitored to prevent any severe damage and 

 closed prior to any grazing in 1981 



12 



