The process of eating and being eaten by the successive creatures is known to as food chain. In short it is the flow of energy from producer to tertiary consumer.
Grazing food chain:
It starts from green plants and through carnivores it reaches to the decomposers for final breakdown of the complex in simpler one. For example grassland ecosystem, pond ecosystem etc.
Parasitic food chain:
When plants and animals get infected by parasites. Smaller organism consumes them without killing them. For example nematode, bug etc.
Detritus food chain:
Food chain that starts from dead and decayed organisms, to the micro-organisms, to the detrivorous or saprovorous and these predator forms a chain called detritus food chain.
There is a long interlinked chain processes in an ecosystem. Different food chains are interconnected with each other in a specific pattern.
A food web presents all possible feeding relationship among various organisms of the ecosystem. If the chain gets disturbed a little, then it leads to the loss of species and the web breaks down.
The slow but continuous replacement of ecosystem over a period of time in any particular area is called ecological succession.
It occurs due to environmental changes. The colonial establishment and extinction of species fall under this process. Through this way the plants and animal species change gradually.
Types of Succession
1. Primary succession:
The area which is the lifeless and unexposed to any life is occupied by a living community for the first time is known to as primary succession of that land.
2. Secondary succession:
When a new biotic community replaces an already existing biotic community then this type of replacement is known as secondary succession. For example farm garden or parlous etc.