Succession Flashcards
(8 cards)
1
Q
what is the process of the pioneer phase of primary succession
A
- lichens and algae colonise bare rock first
- begin to break down rock surface into fragments
- allowing organic material to gather in the broken rock forming beginnings of soil
- algae and lichens decompose forming organic humus layer
- broken rock and humus form thin layer of soil
2
Q
what is the development phase of primary succession
A
- mosses build up more organic material which can retain more water
- small rooted plant species grow into the thin layer of soil
- plants decompose creating a thicker soil
- species of plants begin to compete and dominant species arise
3
Q
what is the climax community phase of primary succession
A
- climax community remains unchanged unless the conditions (abiotic/biotic) in the habitat change
- nature of climax community depends on the environmental conditions
- high biodiversity levels
4
Q
what is a climax community
A
the final stage in succession which is self-sustaining and stable usually with one dominant species
5
Q
primary succession summary
A
- pioneer species lichens and mosses are able to grow in little/no soil
- break up rock fragments and add organic matter (humus) to form a thin soil layer
- small rooted plants are bale to grow in the shallow soil
- soil structure changes - able to hold more water/minerals and as plants die and decay humus increases
- larger plants outcompete shorter species for space and light and replace the previous community
- improved soil enables shrubs and trees to grow
- stable climax community forms which is self-sustaining
6
Q
where does secondary succession occur
A
occurs on existing soil where vegetation (existing community) has been cleared
could be due to natural disasters or ploughing fields
7
Q
what is deflected succession
A
when succession is prevented from running its course due to human interference
8
Q
what is a plagioclimax
A
a climax community that has been reached as a result of human intervention
