Ecological Succession

Succession is the changes, over time, in the species that occupy a particular area.

The first stage of succession is the colonisation of an inhospitable environment by pioneer species. They are adapted for hostile conditions:

• production of vast quantities of wind-dispersed seed or spores
• rapid germination of seeds on arrival
• ability to photosynthesis
• ability to 'fix' nitrogen from the atmosphere
• tolerance to extreme conditions

Succession takes place in a series of stages. At each stage, certain species grow which change the environment so that it becomes more suitable for other species. These other species may then out-compete the existing species so a new community is formed.

In the end a climax community is formed, consisting of plants and animals. In this climax community, there is normally a dominant plant species and a dominant animal species.

• non-living environment becomes less hostile
• greater number and variety of habitats
• increased biodiversity
• more complex food webs
• increased biomass

Conservation is the management of the Earth's natural resources in a way that maximum use of them can be made in the future. There are several reasons to do this:

• ethical: respect for living things who have the right to co-exist with humans
• economic: living organisms contain a huge pool of genes that have the capacity to make millions of substances that may be valuable in the future
• cultural and aesthetic: habitats and organisms enrich our lives, adding interest to it

One way of conserving these habitats and species is by managing succession in a way that prevents a change to the next stage. For example, burning the heather in the moorland or letting sheep graze on it.