Succession Flashcards
What is succession
It is the process of ecosystem change
How may a species alter an environment when it colonises there
It might make it :
Less suitable for the existing species. As a result the new species may out compete the existing one and so take over a given area
More suitable for other species with different adaptations. As a result this species may be or competed by the better adapted new species
Describe primary succession
1) Primary succession- Species colonise a new land surface. Seeds and spores bloom in by the wind and begin to grow. This is called the pioneer species
Abiotic conditions are hostile (harsh). Only pioneer species grow because they’re specially adapted to cope with the harsh conditions
The pioneer species change the abiotic conditions- they die and microorganisms decompose the dead organic materials. This forms a basic soil.
Making conditions less hostile. Soil helps retain water, which means new organisms with different adaptations can move in and grow. These then die and decompose adding more organic material, making the soil deeper and richer in minerals. Shrubs can start to grow in the deeper soil, which retains even more water
Some new species may change the environment so that it becomes less suitable for the previous species
Describe secondary succession
Already a soil layer
The pioneer species in secondary succession are larger plants
What happens after secondary succession
Different plants and animals that are better adapted for the improved conditions move in, out compete the plants and animals that are already there, and become the dominant species in the ecosystem
As succession goes on the ecosystem becomes more complex. New species move in alongside existing species which means that biodiversity increases
The final stage is called the climax community - the ecosystem is supporting the larger and most complex community of plants and animals it can. It won’t change much more - it’s in a steady state
What’s the difference between primary and secondary succession
Primary happens on newly formed land
Secondary is where there is soil remains but no plants
What are the comment features during succession that emerge
Non living environment becomes less hostile leading to a
greater number and variety of habitats and niches that then produce
an increased in biodiversity then this leads to
more complex food webs and the leading to
an increased biomass
