USE OF ANNUAL PLANTS IN CALIFORNIA FOOTHILLS 37 



period promotes the growth of green forage in two ways. First, the 

 upright herbage protects the new plants from drying winds and sun. 

 Second, the decomposing herbaceous material lying flat on the soil 

 surface, and partially intermixed with the mineral soil, conserves moisture 

 and aids establishment and early growth of each year's seedlings. In the 

 grazing-intensity pastures, herbage production during the winter was 

 observed to be consistently greatest on range land with an adequate 

 layer of decomposing litter. Exceptions occurred on small spots recently 

 cultivated by gophers or where moisture accumulated at the base of 

 boulders; but on the whole, plant growth was sparse where there was a 

 shortage of litter on the soil surface. 



The layer of old litter was not maintained over most of the soil surface 

 in the two pastures that had been grazed closer than moderate. In 

 pasture 3 (closely grazed), of 99 square-foot quadrats examined in 

 January 1943, about 75 percent had almost no litter; about 15 percent 

 had a thin, spotty cover; and less than 10 percent had a fairly continuous 

 layer of decomposing herbaceous material. In pasture 1 (grazed moderate 



300 



200 



Uj 

 CO 



Jk 100 



I 



NONE 



I 



OLD LITTER ON SOIL SURFACE 

 FAIR 



I 





I 





1 



ADEQUATE 



1 

 I 





CLOSE MODERATE LIGHT CLOSE MODERATE LIGHT* CLOSE® MODERATE LIGHT 



UTILIZATION OF PRECEDING SEASON 



•SMALL SAMPLES 



Figure 16. — Yield of new green vegetation in air-dry weight pounds per acre, clipped 

 at 3^-inch stubble height, as influenced by the layer of old litter lying flat on the 

 soil surface and by the degree of utilization of the preceding season.' 



