Succession Flashcards
What is ecological succession?
The process by which communities in a particular area change over time
Succession takes place as a result of complex interactions. What are these complex interactions
Biotic and Abiotic factors
What has occurred in the past community?
Some species in the past community were out-competed or did not tolerate altered abiotic conditions
Present community modifies abiotic factors as…
4 things
- Light intensity and quality
- Wind speed and direction
- Air temperature and humidity
- Soil composition and water content
The process of future community…
Changing conditions in the present community will allow new species to become established. These will then make up the future community
A succession (or sere) proceeds in ______ _______.
Seral stages, until the formation of a climax community, which is stable until further disturbance
Early successional (or pioneer) communitues are characterized by: (3 things)
- Simple structure, with a small number of species interactions
- Broad niches
- low species diversity
In contrast to early successional communities, climax communities typically show
(3 things)
- Complex structure, with a large number of species interactions
- Narrow niches
- High species diversity
Primary succession
Colonization of a region where there is no pre-existing community
Examples of primary succession
- newly emerged coral atolls, volcanic islands
- newly formed glacial moraines
- islands where the previous community has been extinguished by volcanic eruption
A classical sequence of colonisation begins with ____, _____ and ______, progresses to _______, _______, ______ and cumulates in a _______ _______ of mature forest.
lichens, mosses, liverworts, ferns, grasses climax community
Where does secondary succession occur?
Occurs where an existing community has been cleared by a disturbance that does not involve complete soil loss
Such disturbance events for secondary succession include
Cyclone damage, forest fires and hillside slips
Does the a secondary succession ecosystem recover faster or slower than primary succession?
Because there is still soil present, the ecosystem recovery tends to be more rapid than primary sucession , although the time scale depends on the species involved and on climatic and edaphic (soil) factors.
