Succession Flashcards
What is succession?
Succession is the process by which an ecosystem changes over time. The biotic conditions change (plant and animal communities) as the abiotic conditions changes (water availability).
Types of succession
Primary succession - happens on newly formed land or newly exposed land.
Secondary succession - happens on land that has been cleared of plants but soil remains.
Conservation
Is the protection and management of ecosystems and involves managing succession
What has happened when the climax community is called the plagioclimax?
Succession stopped artificially.
What is involved in conservation?
Preventing succession in order to preserve an ecosystem in its current seral state. Eg conserve moorland
Animals grazing: eat the growing points of plants which stops them establishing themselves, keeps vegetation low.
Managed fires: after the fires secondary succession will occur and the pioneer species that grow back first are the species that are being conserved. Larger species will take longer to grow back and will be removed again when the moor is burnt.
Why is conservation important?
Species are resources: drugs, clothes, food.
Useful in the future.
Right thing to conserve species as they have the right to exist.
Bring joy, attractive to look at.
Prevent climate change - if trees are conserved co2 is released when they are burnt.
Helps to prevent the disruption of food chains.
A farmer has a field where he plants crops every year. When the crops are fully grown he removes them all and then ploughs the field (churns up all the plants and soil so the field is left as bare soil).
The farmer has decided not to plant crops or plough the field though for several years.
A) describe in terms of succession what will happen in the field over time. 6marks
This is an example of secondary succession because there is already a soil layer present in the field.
The first species to grow will be the pioneer species which will be larger plants.
These will be replaced with shrubs and smaller trees.
At each stage different plants and animals that are better adapted for the improved conditions will move in, outcompete the species already there and become the dominant species.
As succession goes on the ecosystem becomes more complex so species diversity increases.
Large trees will grow forming the climax community which is the final seral stage.
A farmer has a field where he plants crops every year. When the crops are fully grown he removes them all and then ploughs the field (churns up all the plants and soil so the field is left as bare soil).
The farmer has decided not to plant crops or plough the field though for several years.
B) explain why succession doesn’t usually take place in the farmers field. 2marks
Ploughing destroys any plants that were growing.
So larger plants may start to grow but they won’t have long enough to establish themselves before the field is ploughed again.
Use your knowledge to outline the reasons for the conservation of tropical rainforests. 6marks
Conserving rainforests is important for humans as they may provide lots of things that humans need such as clothes, food or drugs.
If they are cut down the source of these things will be lost for future generations.
Some people think rainforests should be conserved because it is the right thing to do as they think rainforests have the right to exist.
Rainforests bring joy to many people who visit them if they are cut down they can’t be enjoyed in the future.
Conservation of rainforests will mean that less trees are burnt, this prevents climate change because less co2 will be added to the atmosphere causing global warming.
Conserving rainforests will help to prevent the disruption of food chains, a decease in one species could mean the loss of many more species in the food chain as there is less food so more resources are lost.
Name 2 suitable methods that could be used to conserve species from a tropical rainforests. 2 Marks
Seedbank
Captive breeding programme
Relocation
