Mutual interrelationship among individuals of a community

Mutual interrelationship includes all the direct and indirect effects that organisms have upon each other. The three relationship which we shall discuss are (a) competition, (b) stratification, and (c) depkndence.

a) Competition: Demand for a common resource by different organisms results in competition. Competition between individuals of different species is called interspecific; when it occurs between individuals of the same species it is called intraspecific.

b) Stratification: Different organisms in a community develop a characteristic pattern of stratification to minimise competition and conflict among the members of the community. Plants and animals of each layer differ in size, behaviour and adaptation from those of other The tall growing trees form the overstory and modify the light and moisture conditions for the shorter trees growing under them. These in turn determine the conditions for the ground
vegetation. In moist tropical rain forests upto five distinct strata can be formed.

C) Dependence: In a community there are some species which are wholly dependent on the dominant member for survival. Bryophytes, thallophytes and a few vascular small plants are examples of such organisms. These dependent organisms require special conditions such as shade and moisture provided by the dominant species. The dependent species will die if the dominant species are eliminated.