VEGETATION ON DRIVEWAYS AND BED GROUNDS 1 19 



shallow-rooted, short-lived perennials. As would be expected, 

 the vegetation as a whole is most inferior and sparsest on the 

 seriously eroded parts; on the other hand, it is highest succes- 

 sionally and the most desirable and abundant on the noneroded 

 portion. 



Vegetation on Driveways and Bed Grounds. — The use for 

 many seasons in succession of estabhshed driveways and bed 

 grounds brings about a type of vegetation similar to that found 

 on badly eroded areas — plants that are embraced chiefly in the 

 first weed stage. Not uncommonly such areas represent the 

 most serious destruction of the plant cover that can occur on 

 pasture lands. On long-used bed grounds, for instance, all of 

 the stages of vegetation described are frequently found in belts 

 around the bed ground proper. Figure 35 shows a bed ground 

 that was used for many seasons in succession. The bed ground 

 proper (zone i) is practically circular and covers 22 acres. Be- 

 cause of heavy and repeated use each year not a vestige of vegeta- 

 tion remains. On the basis of the density and palatability of the 

 original cover this area would have supported in good condition 

 14 sheep, or 3I mature cows, for the summer season of 100 days. 



Surrounding the bed ground proper is an area (zone 2) 

 of about 85 acres. Here the vegetation consists entirely of 

 plants of the first or early weed stage. On the basis of the density 

 and palatability of the original cover, this area would have main- 

 tained in good condition for the summer season 65 sheep, or 16 

 cows; whereas it now supports 5 sheep, or i| cows. 



Zone 3 comprises about 215 acres and has a mixed cover of 

 plants of the first and early second weed stages. If it is assumed 

 that half of the present vegetation is palatable to stock, it may 

 now carry 16 sheep, or 4 cows; whereas it would formerly have 

 furnished feed during the regular grazing season for 130 sheep, 

 or about 32 mature cows. 



Zone 4 has a mixed cover of perennial grasses and weeds and 

 comprises an area of approximately 350 acres. About three- 

 fourths of the cover is palatable. It will now carry 105 sheep, 

 or 26 cows; whereas formerly it would have supported not less 

 than 210 sheep, or 52 cows. 



