Page:The Journal of Indian Botany.djvu/353

Rh nial grasses are destroyed, and the ground left practically bare (Fig. 14).

In consequence of the severe grazing there is no cover of vegetation on the ground to aid in conservation of the monsoon rains. Where drainage has been established, runoff of the monsoon rainfall is very rapid and complete ; where the land is flat, the vegetation has no effect in preventing runoff.

The scattering thorny shrubs and small trees, with a few inedible exceptions, are kept eaten done to small dense rounded bushes wherever and as long as animals are able to reach them.

Cutting for food and fuel. In India a very large proportion of the plants comprising the flora is made use of by man for some specific purpose, especially for food and medicines. Perhaps the results of all such exploitation are not in the longrun very detrimental. Usually it is parts that are not essential to the life of the plant that are used for food. It is for forage and fuel that man works the greatest havoc with the vegetation. Throughout the year, and especially during the hot season, much of the available grass covering is cut off just below the surface of the soil for fodder for domestic animals. It is only the most persistent perennials that can survive such treatment. In the Upper Gangetic Plain no natural fuel remains except a few species of xerophytic shrubs and small tres3, and in most places these are periodically cut, sometimes almost to the extinction point. The fine groves about villages are all planted, and these alone escape the unremitting struggle of man to find fuel. There is no attempt locally at conservation of plant resources.

Wild fires are negligible as a factor influencing vegetation, for the reason that the land is so intensively cultivated and grazed that there is nothing left to burn.

Wild grazing animals are not numerous and are of little importance. Earthworms are abundant during the rains, and their burrows probably are of considerable importance in promoting aeration and water penetration. Numerous species of black ants probably render a similar service. In general, insect pests are relatively unimportant. It is uncommon to find the indigenous vegetation eaten to any great extent.

White ants, White ants are the only insects that exert any great influence on the vegetation. They are found everywhere and are almost unbelievably abundant. Doubtless their burrows function as do those of the black ants, and they reach a depth of 5 feet or more. It is only rarely that white ants attack living plants, though they closely follow dieing parts and keep them eaten away. When grasses and other plants, especially the annual vegetation, die, the