Ecological Succession
The process by which communities of plant and animal species in an area are replaced or changed into another over a period of time , is known as ecological succession.
Steps involved in ecological succession
The ecological succession is a complex process and it may take thousands of years the process of succession is completed through a series of sequential steps that are given below :
1. Nudation
2. Invasion
3. Competition and co-action
4. Reaction
5. Stabilization
1. Nudation
Location is the development of a bare area (an area without any life form ).
It is first step in ecological succession.
The causes of nudation are:-
a) Topographic - soil or topography related cause such as erosion ,landslide , affected result information of bare area.
b) climatic - glaciers , dry period, and storm
c) Biotic - forest destruction ,agriculture and disease epidemics it result in total destruction of population in an area.
2. Invasion
Invasion is a successful establishment of a species in the bare area.
A new species reaches the newly created their area and try to establish their.
Process of invasion is completed in 3 steps:-
A) Migration
Speed sports propagules of a species reach the bare area due to migration.
B) Ecesis
It is the process of successful establishment of a species in the bare area.
The seeds or sports will germinate and reproduce .
C) Aggregation
After ecesis, the individual of a species increase their number and they stay close to each other this process is called aggregation.
3. Competition and co-action
Aggregation results in the increase of the number of species within a limited space.
The competition maybe intra specific or inter specific.
Competition and co-action results the survival of fit individual and elimination of unfit individual from the ecosystem.
4. Reaction
It is most important stage in ecological succession.
It is the modification of the environment through the influence of living organism present on it .
Reaction cause change in soil, water, light and temperature of the area
Due to these modification, the present community becomes unsuitable for the existing environmental condition.
5. Stabilization
It is the last stage in ecological succession.
The final or terminal community becomes more or less stabilized for longer period of time.
The final community is called climax community
Example- forest ,grassland , coral reef.
Types of succession
1) primary succession - it occurs in the area where no life exist earlier.
2) secondly succssion - it occurs in the area where life exist earlier but destroyed.
3) autogenic succession- it occurs as a result of biotic factor.
4) allogenic succession - it occurs as a result of abiotic factor.
Cause of succession
Three major causes have been identified for the process of succession.
1. Initiating cause
These include biotic and climatic factor which destroy the existing population of an area.
2. Continuing cause
These processes are continuous such as aggregation competition migration etc.
3. Stabilizing cause
These include the climatic factors resulting in stabilization of community.
