Here is the presentation of Wind.This presentation also contains some brief description on Direct effect of wind, Indirect effects.

1. Wind

2. • Air in motion is called wind. It can circulate gases, water vapours and small
soil particles. The action of wind is an ecological factor. Its affect may be
direct or indirect. The direct effects of wind are seen in regions with
continuous action of high wind velocities. There are following affect of
wind:
1. Direct effect of wind
It has following direct effects:
• (a) Plants may be uprooted and blown away by storm winds in Coastal
regions or exposed mountain tops. Therefore, the vegetation of these areas
is largely composed of species with prostrate or stunted growth. They have
well developed underground roots or rhizome system.

3. • (b) There is a continuous and unidirectional
wind pressure in coastal regions. Therefore, the
trees and their branches direct themselves
towards the lowered side.
• (c) The branches of large trees are broken or
entire trees are uprooted in strong winds or
hurricane.
• (d) Violent winds cause flattening of the
herbaceous plants to the ground. It is
called lodging. It takes place in herbaceous and
weak stemmed plants like grasses, maize,
wheat, corn, sugar-cane etc.
• (e) Strong wind also carries sand particles.
These particles have abrasive action on the
leaves and tender branches. Crops grown near
sandy tracts suffer from abrasive action of the
wind.

4. 2. indirect effects
• Indirect effects of wind are physiological.
These are:
• (al Transpiration: Wind influences the rate of
transpiration of plants. Air currents take
away the air saturated with water vapour. It
increases the transpiration. Wind velocity
increases with height above the surface of
the soil. Therefore, large plants are more
affected by high rates of transpiration than
the smaller ones.
• (b)Stunted growth: Strong winds increase
transpiration rapidly. The plants can not
maintain an internal water balance.
Therefore, these plants suffer from
dehydration. They losses turgidity.
Therefore. their organs become dwarfed.

5. • (c)Soil erosion: Wind also causes
erosion of soil by carrying out soil
particles.
• (d) Dispersal of pollen grain, seed
and fruit. Wind is also important
for dispersal of pollen grains,
seeds and fruits.