Read this article to learn about 7 Effects of Air on Vegetation !
(i) Wind increases the water loss by constantly removing the air saturated with water vapour from the intercellular spaces of the leaves and bringing unsaturated air in contact with leaves and young shoots.
(ii) Mechanically, wind causes erosion of soil and abrasion of vegetation through removal of particles. Physiologically, it decreases the growth of plants by way of reducing the moisture content of air and reducing the turgidity of plant parts on which it impinges. Moist air promotes the growth of mesophytes.
(iii) In strong dry and hot winds, young parts of plants may become shriveled and killed in a few hours and the surface of soil may become dry.
(iv) In open situations, e.g., seashores and High Mountain tops, where the strong winds blow all the year round in one direction, the trunks and branches of trees are twisted chiefly in the direction of prevailing wind. In such plants, generally, the growth of buds becomes checked on windward side (Fig. 2.7).
(v) In strong winds, big trees are uprooted and small plants and grasses are affected but to a very little extent. By strong wind, weak plants like wheat, maize, sugarcane, jowar, etc., are bent against the ground. These lodged plants, if their stems are not too mature, may become partially erect. This is due to differential growth of the meristematic lower nodes of these plants.
(vi) Wind is an important agent for the dispersal of pollen grains, fruits, seeds and spores of the plants. In deserts, the strong wind carries the sand and seeds. Thus, it plays important role in local distribution of plant species or communities of plants. Some types are wind resistant but some may be totally dependent on wind for their dispersal. Many plants are unable to flourish or even exist in the exposed situations if they are brought to such places by wind. Strong wind causes injuries to plants growing at high altitudes. In desert, the storm results in big sand-dunes which cover the vegetation (Fig. 2.8).
(vii) In the areas subjected to strong winds, the leaves of plants become small and rolled. The transverse section of stem shows eccentrically developed secondary wood, i.e., the diameter of the trunk in the direction of wind becomes greater than that at right angle to it. The plants in such areas show extensive development of mechanical tissues which provide mechanical support and save the plants from wind injuries.
In India and many other countries of the world, unchecked winds have caused total disappearance of vegetation at certain places and rendered big areas deserted. Rajasthan desert in India is spreading eastward due to unchecked wind erosion.