Disturbance seems to occur in all ecosystems. It plays a major in the generation and maintenance of species diversity and related aspects of community organization. Disturbance is an important selective force in the evolution of plant life history designs and the resulting population characteristics. Thus there may be different life history designs for different disturbance regimes. The size, intensity, frequency, and regularity of occurrence of disturbance vary considerably and these interact dynamically with the species that experience this variation. There are many agents of disturbance in nature. However irrespective of its characters and causes, disturbance may be defined as a sudden change in the resource base of a unit of the landscape that is expressed as a readily detectable change in popular response.
