. Efficient use of annual plants on cattle ranges in the California foothills . F-460561 Figure 17.—Appearance of foothill range in January—the time of year when condition of the soil surface is best rated. during the spring because it is more completely masked from view by vegetation. Then, too, differences in grazing during the preceding months affect plant height in the spring so as to obscure the effects of soil-surface condition on plant vigor. During the winter months, how- ever, both the litter layer and the vigor of new plant growth can be con- sidered as indicators of the productive c
. Efficient use of annual plants on cattle ranges in the California foothills . F-460561 Figure 17.—Appearance of foothill range in January—the time of year when condition of the soil surface is best rated. during the spring because it is more completely masked from view by vegetation. Then, too, differences in grazing during the preceding months affect plant height in the spring so as to obscure the effects of soil-surface condition on plant vigor. During the winter months, how- ever, both the litter layer and the vigor of new plant growth can be con- sidered as indicators of the productive condition of California foothill ranges. A foothill range with unsatisfactory soil-surface condition has very little decomposing herbaceous material on the soil surface, and the sparse and stunted plant growth provides only a thin vegetative cover. Mineral soil is readily apparent during the winter months over all of the range in unsatisfactory condition. The hard, exposed soil surface inhibits the establishment and growth of annual-plant seedlings. There are other indicators of unsatisfactory conditions. The mineral soil is commonly covered with a short growth of moss, lichen, or plants of similar appearance. The thin, black humic layer that ordinarily covers the mineral soil may disappear after the overlying herbaceous layer is lost. A miniature erosion pavement is often formed as a result of loss of organic matter and possibly of some fine mineral soil. After heavy rains, local movement of soil particles is evident in the tiny terraces that are formed even on gently rolling slopes, and particularly on south slopes. Even so, accelerated erosion may not be readily apparent on foothill ranges with unsatisfactory soil-surface condition. Close examination may reveal slow insidious movement of the soil, as in closely grazed pasture 3r
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