Succession is the process by which ecosystems change over time due to changes in the environment, causing the plant and animal species present to change.

A pioneer community is first stage of succession in which pioneer species colonise an inhospitable environment and make it more suitable for other species, facilitating further stages of succession.

Pioneer species can usually:

1. Reproduce asexually
2. Produce wind-dispersed seeds
3. Germinate rapidly
4. Photosynthesise
5. Fix nitrogen from the atmosphere
6. Tolerate extreme conditions

A climax community is a stable ecosystem with a balanced equilibrium of species, characterised by a small number of dominant plant and animal species that are rarely replaced by new species.

Biodiversity increases during succession, peaking in mid-succession, but decreases in the climax community due to dominant species outcompeting others.

Food webs are more complex when biodiversity is higher

During succession, key species change the abiotic factors making the environment less hostile.

Soil forms and retains more water, nutrients become more plentiful, and plants provide shelter. This makes the environment more suitable for other species.

1. Primary succession - occurs on new or exposed land with no soil or organic material
2. Secondary succession - occurs where soil is present, but there are no plant or animal species

Animal succession occurs alongside plant succession. Primary consumers like insects arrive first, followed by secondary consumers once a suitable food source is established.