All of the following result from overgrazing in semiarid regions except regeneration of grasses soil compaction reduced local rainfall topsoil erosion

regeneration of grasses

Semiarid region are subtype of dryland. These regions are drought regions. The soil in these regions is dry and degraded.  This region receives very low rainfall. The soil lacks essential organic humus, nutrition and appropriate moisture content. Therefore, grasses will not regenerate after overgrazing.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.