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Primary and secondary succession (Primary succession ((As plant species…
Primary and secondary succession
Primary succession
Primary succession occurs when communities develop on entirely new land without any established soil
This may occur at river deltas, glaciers, sand dunes or on exposed rock
pioneer species like lichens and mosses died, they decompose, which creates the first organic soil capable of sustaining plant growth
As plant species colonise the area, the litter produced by their growth and their decomposing remains will cause changes:
Soil depth will increase (as plants add humus to the soil) and soil pH will become altered
Soil mineral content will increase and rocks will begin to be broken down by the action of roots
The soil will become aerated and water retention is increased (drainage is reduced)
larger plants will eventually outcompete smaller shade intolerant plants
Secondary succession
Secondary succession occurs when succession starts on existing soil following the upheaval of a pre-existing ecosystem
This upheaval results in the removal of existing biota and allows a new ecosystem to develop on the site of the old
Because the soil is already developed, dominance is usually achieved by the fastest growing plants
a bushfire or earthquake, destroys the pre-existing climax community
Grasses and herbaceous plants are the first to grow back as the soil is already present (no pioneer species required)
Fast growing trees will develop to their fullest, while shade tolerant trees will develop in the understory
Eventually the fast-growing trees may be overtaken by larger, slower-growing trees as the ecosystem reverts to its prior state
Ecological succession describes the process by which a sequence of increasingly complex communities develop over time
Deforestation is the permanent destruction of a forest via the removal or clearance of trees
Deforestation is the permanent removal of trees to make room for something besides forest. This can include clearing the land for agriculture or grazing, or using the timber for fuel, construction or manufacturing.
