Wind

Strong current of air is known as wind, it is an important ecological factor as it affects plant life mainly on flat plains, along sea coasts and at high altitudes in mountains. It directly affects transpiration, causes mechanical ,damage and is an important agent of dispersal of pollens, seeds and fruits.

Plants in particular have a number of physical as well as anatomical and physiological adaptation to windy conditions. For example, high velocity winds may cause the breaking of branches of trees or even uproot the whole tree. In forests where there are trees of different heights the wind velocity is reduced by about 80 per cent, and damage is much less. Such. trees in forests serve as natural windbreaks or shelter belts. A windbreak is a densely planted strip of tall trees usually between 15 m and 60 m wide, oriented at right angles to thedirection'of the wind so as to reduce the wind velocity near the ground. Windbreaks reduce the rate of transpiration, evaporation, abrasion, breakage, and soil erosion by wind. Often special trees and shrubs are planted around fields and orchards to provide protection against the damaging effects of strorlg winds.

In windy areas such as high mountains and coastal regions the canopy of trees becomes abnormal and becomes flag type or one sided. Branches fail to develop on a windward side but develop towards the leeward side due to the protection provided by the stem.