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Control The Growth Of Algi: Liquid chlorine was first e ployed in 1909 and was commonly added ji prior to filtration; now it is applied both bef< and after filtration. Chlorination materially i proves the coagulation of some waters, Pi chlorination may also control the growth of algi reduce biological accumulation in filters, a contribute to improved Filter efficiency.
Lateral growth in trees frequently begins later than growth in height, but the period of lateral growth is longer. Rates of lateral growth likewise are low at the outset, increasing after a few weeks and then diminishing. In view of the long annual period of lateral growth in trees, deleterious environmental conditions may exercise a pronounced effect on growth. In the wood of trees of temperate regions, narrow and wide growth rings may be observed, marking years characterized by unfavorable and favorable conditions for growth.
With the ever-increasing demand for livestock, overgrazing presents a serious problem in many areas, particularly in Asia and Africa where control is difficult due to tradition, local custom, and common land use. Equally disastrous is the removal of grassland for crop production in areas of deficient water supply. After a few years of cropping, these areas revert to weed and shrub growth and are unable to support grass.
Types of Grasslands. Grassland vegetation ma) be classified in many ways, as by dominanl species, growth form and habit, site or habitat, or use. A classification based on ecological factors such as growth habit, climate, soil, and biotic influences is commonly used. In this classification primary recognition is given to the influence of climate on species association and growth habit.
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