as the village water supply and laundry, as the village sanitary system, and finally as a source of water for irrigation. Ponds that appear promising places for study one year are devastated the next (Fig. 9). The result is that for the most part succession must begin as the beginning each year. Instead of the topographic succession, pools present year after year mUch the same appearance for a given season, and seasonal rather than topographic succession is conspicuous. This renders the study of topographic succession very difficult, and everywhere emphasizes the struggle that is going on between man and nature, and the balance that has become established between them. By far the largest part of the area is as far advanced in succession as is possible under existing conditions (Fig. 11).
Details of topographic succession.
In more favored parts of the earth where vegetation has a chance to develop naturally, it is possible to study with considerable precision the gradual development of the flora from the most primitive conditions to the most advanced association of plants that the area can support; For the most part studies in plant succession have been made in temperate regions, where there is but one vegetational season, the summer or growing season. This is followed by a winter season during which the vegetation is at more of less of a standstill. In the Upper Gangetic Plain there is no season in which growth is impossible. Growth is checked and the vegetation modified by the aridity of the hot season, and at all seasons and at every stage it is interferred with even to the extinction point by the human factors. Therefore it is not an easy matter to trace the steps of topographic succession. The problem is further complicated by the seasonal succession. Yet in spite of the difficulties, it has been possible to find a few favorable spots which give a clue to the early stages of succession, and others which indicate what the higher stages would be if the human factors were lessened or removed.
Stages is the topographic succession. It is convenient to divide the succession into the following stages:—
- 1. Aquatic stage.
- 2. Wet meadow stage.
- 3. Dry meadow stage.
- 4. Thorn scrub stage.
- 5. Pioneer monsoon deciduous forest stage.
- 6. Climatic climax monsoon deciduous forest stage.
