Succession and Conservation Flashcards
What is succession?
The process by which an ecosystem changes over time in a series of stages where at each stage the species in the area change the environmental conditions.
What is primary succession?
Happens on land which has been newly exposed so there’s no soil present, just bare rock.
- Pioneer species – the first species to colonise the area
- Pioneer species die and decompose – the pioneer species die and are decomposed by microorganisms
- Changes abiotic conditions – the abiotic conditions are changed as the decomposition of the pioneers creates a thin layer of soil, making conditions less hostile
- Larger species of plant arrive – larger species of plant can grow in deeper soil which retains more soil and nutrients
- Outcompete – plants which are better adapted to the abiotic factors outcompete the plants already there and become the dominant species
Eventually the climax community is formed. The climax community is when the ecosystem supports the largest and most complex community of plants and animals as possible.
What is secondary succession?
Happens on land that’s been cleared of all the plants by where the soil remains.
Similar to primary succession but because there’s already a soil layer, secondary succession starts at a later stage- and the pioneer species are larger plants, e.g shrubs.
What is the climatic climax?
The climax community for a particular climate.
What is conservation?
The protection and management of species and habitats.
What is a plagioclimax?
Succession is stopped artificially by human activities stopping a climax community from happening.
Conservation methods?
- Management of succession.
- Seedbanks.
- Captive breeding.
- Relocation.
- Protected areas.
Why is conservation important?
Economic reasons – resources such as food, clothes and drugs
Environmental sustainability
Ecological reasons – prevent climate change. E.g. trees are carbon sinks
Managing succession
Stopping a climax community from developing
The ecosystem is preserved in its current state
Seedbanks
Can store the seeds of endangered species
Store a range of seeds from plants with different characteristics
If plants become extinct, stored seeds can be used to grow new plants
Large number of seeds can be stored because they’re small, and can be stored for a long time as long as it’s cool and dry
But have to be regularly checked to see whether they can still grow into a plant
Captive breeding
Breeding endangered animals in captivity to increase their numbers
Can be reintroduced into the wild
But reintroducing the animals back into their wild habitats could bring new diseases into the habitat
Relocation
Moving a species to an area where it’s not at risk, such as a national park
Relocated to a similar environment to where it’s from so it can still survive
But native species to the area could be outcompeted by the species that has been relocated
Protected areas
National parks and nature reserves protect habitats
But they are often tourist destinations
Why does biomass increase as succession continues?
Pioneer species- hostile to less hostile
Allows new species to colonise as env changes
Increase biodiversity, niches, more organisms etc.
Explain the process of mark release recapture.
- Capture a sample of a species using an appropriate technique.
- Mark them in a harmless way.
- Release them back into their habitat.
- Wait a week, then take a second sample from the same population.
- Count how many of the second sample are marked.
- Use this equation: total population size = number caught in first sample x number caught in second sample/ number caught in second sample.
