• Succession is the process by which an ecosystem changes over time
• Succession occurs in a series of stages of where each stage the plant and animal communities in an area slowly change the environmental conditions (both abiotic/biotic)
• These changes in environmental conditions aid the ability for other species with different adaptations
• Results in one community of organisms to be succeeded by another
Primary Succession
• Occurs on newly formed/exposed land
• There is no soil or organic materials to start with
Pioneer stage of succession
1) Species colonises a new land surface
2) Seeds and spores are brought in via the wind and thus begin to grow
3) First species to colonise the area are the pioneer species
4) Abiotic conditions are hostile and only pioneer species can grow because they are specially adapted for them
5) Pioneer species are able to change the abiotic condition making them less hostile
 When they die saprobiontic decompose the dead organc material which forms the (basic) soil
6) Therefore, conditions because less hostile so new organisms with different adaptations can live there
7) New organisms die and decompose
 Further adds organic matter and makes the soil deeper and rich in minerals so much so that nitrogen-fixing bacteria can turn nitrogen  ammonia
 Ammonium ions in a solution can be used in plants therefore increasing plant growth
8) Larger plants are able to grow in the nutrient rich soil
*Some species can increase the hostility of an area
Later stages of succession
1) Different plants and animals that are better adapted to the improved conditions are able t move in
o These outcompete pre-existing species and become the dominant species
2) Dominant species causes the greatest change to the abiotic environment (thus making it more suitable for other species to live with)
3) As succession continues the complexity of the ecosystem increases so biodiversity increases
4) Eventually, a climax community is reaches where the ecosystem is supporting the largest and most complex community of plants and animals it can
5) It will not change significantly from this point