Ecological Adaptations

Ecological adaptations are special characteristics developed by organisms in order to live comfortably and successfully under a prevailing set of environmental conditions. Ecological adaptations may be morphological, physiological or behavioural or a combination of them. They develop through the process of natural selection of the variations already present (preadaptations) or a slow natural selection of small variations having adaptive traits. The ultimate aim of all adaptations is to make the individual fit to obtain food and space for its survival, opportunities for its reproduction and rearing of young ones.

PHENOTYPIC PLASTICITY AND ECOTYPES

Phenotype is the physical expression of the interaction betwen genotype of an organism and its environment. The phenotypes show variations due to differences in the environmental conditions within the local habitat.

Such variation among individuals produced by the influence of the local conditions of the habitat is known as phenotypic plasticity. It results in the formation of ecotypes.

Ecotypes are those species having a wide range of distribution evolve genetically adapted local populations.

Ecotypes differ from each other on the basis of morphological and physiological characters. Although ecotypes of a species differ genetically they are interfertile. Ecotypes are commonly found among plants and sessile animals.

STRATEGIES OF ADAPTATIONS IN PLANTS

Plants'' have special traits that help them to enlarge their tolerance limits to light regimes, dry conditions, high temperatrue, water-saturated conditions, and saline environments. In plants, flowers have evolved special structures to ensure pollination by insects or other animals. Plants have developed various mechanisms to deal with stress conditions of the environment.

PHENOTYPIC PLASTICITY AND ECOTYPES

Phenotype is the physical expression of the interaction between genotype of an organism and its environment. The phenotypes show variations due to differences in the environmental conditions within the local habitat. Such variation among individuals produced by the influence of the local conditions of the habitat is known as phenotypic plasticity. It results in the formation of ecotypes.Ecotypes are those species having a wide range of distribution evolve genetically adapted local populations. Ecotypes differ from each other on the basis of morphological and physiological characters. Although ecotypes of a species differ genetically they are interfertile. Ecotypes are commonly found among plants and sessile animals.

STRATEGIES OF ADAPTATIONS IN PLANTS

Plants have special traits that help them to enlarge their tolerance limits to light regimes, dry conditions, high temperature, water-saturated conditions, and saline environments. In plants, flowers have evolved special structures to ensure pollination by insects or other animals. Plants have developed various mechanisms to deal with stress conditions of the environment.

ADAPTATION TO LIGHT REGIME

On the basis of adaptation to different light intensities plant communities are classified into two categories :

• Sciophytes : Shade loving plants, generally have low photosynthetic, respiratory and metabolic activities e.g. fern, herbaceous plant growing under dense, canopy of forests.
• Heliophytes : (Sun adapted) Adapted to high intensity of light and have high temperature optima for photosynthesis, as well as have high rate of respiration e.g. shrubs and trees.

Sun plants are adapted to higher temperature optima for photosynthesis and high rates of respiration. Shade plants have lowphotosynthetic, respiratory and metabolic activities. Perfect shade tolerant plants are ferns and several herbs which grow on forest floor under the canopy of trees and shrub.