Ecological Succession Flashcards
What is sere mean?
A series of successional changes
Ie each stage
What is a pioneer species?
The first colonisers of bare rock. They’re able to survive due to specialised features.
Name characteristics of a pioneer species
Fast reproduction
Rapid germination
Tolerate extreme conditions
Independent
What are annuals?
Come after pioneer species in succession
Eg moss
How do pioneer species allow succession to take place?
They create nutrients so other organisms can live there
- the more species present, the more nutrients created so even more species can live there
Where does primary succession take place?
Bare rock or barren terrain
Where does secondary succession take place?
An area which previously supported life, was made barren then recolonised
- so succession does not begin with a pioneer species
What is succession?
Describes how ecosystems and their communities change over time
Explain changes in above ground biomass over the period.
Imagine graph where curve is slowly increasing, then more constant increase, then levels off
Slow at first as little nitrogen in the soil.
Becomes constant as nitrogen levels rise so removes limit on growth.
Levels off as soil nitrogen levels fall since plants take it into their biomass. This leads to limit on plant growth.
Give 3 examples of pioneer species
Linchen
Reeds
Rushes
Gives examples of what succession is a result of
Glaciers retreating & depositing rock
Volcanoes erupting & depositing lava
Land subsides, creating lakes & ponds
What is a climax community
Ultimate community with a stable state of a balanced equilibrium of species with barely any species replacing those established
Describe flow chart of how a non-livable environment can change
Non-livable environment becomes less hostile Greater number & variety of habitats Increased biodiversity More complex food webs Increased biomass
Define preservation
Maintaining individuals, populations and ecosystems in their current state without the exploitation of their natural resources
Define conservation
Allowing ecosystems to evolve naturally, without resources being overused - therefore detrimentally affecting succession
