Succession Flashcards
What does the term “succession” mean?
Succession is a term used to describe the changes that occur over time in a species that occupy a particular area
During succession, what occurs?
During succession, the biotic and abiotic conditions change over time
What is primary succession?
Primary succession is the process that occurs when newly formed or newly exposed land is gradually colonised by an increasing number of species
What can cause barren land to form?
Succession will take place in a series of stages, where at each stage a new species will colonise the area
Primary succession does not only occur on bare rock, what other type of land does primary succession occur on?
Primary succession can occur on any barren terrain, like sand dunes
What is the first stage of primary succession?
The first stage of primary succession is the colonisation of an inhospitable environment by organisms called pioneer species.
As these pioneer species die and decompose, the dead organic matter forms a basic soil
What is the second stage of primary succession?
The seeds of small plants and grasess, sometimes carried by the wind, land on this basic soil and begin to grow.
As these small plants and shrubs die and decompose, the new soil becomes deeper and more nutrient - rich
The roots of these small [plants and shrubs also form a network that helps t hold the soil in place and prevent it from being washed away
What is the third stage of primary succession?
Larger plants and shrubs, as well as small trees, that require deeper, more nutrient - rich soil, can now begin to grow
What is the fijnal stage of primary succession?
FInally, the soil is sufficiently deep, containing enough nutrients and holding enough water to support the growth of large trees
These final species to colonise the new kand become the dominant species f the now relatively complex ecosystem
The final community formed, containing all the different plant and animal species that have now colonised the new land, is known as the climax community
At each stage of succession, what occurs?
At each stage of in succession, there are certain species that gradually change the local environment so that it becomes more suitable for the species that have not yet colonised the new land
What does the colonisation of new species cause within the environment?
With each new species colonizing an area, there may be a change in the environment making it either less suitable for the existing species or more suitable for other species with different adaptations
If the environment is changed to be less suitable for an existing species, what results from this?
As a result of the environment being less suitable for existing species, the new species may out compete the existing one and so take over a given area
If the environment is changed to be more suitable for other species with different adaptations, what results from this?
As a result of the environment being more suitable for other species with different adaptations, the new species may be out competed by the better adapted new species
There are a series of successional changes which alter the abiotic environment.
What do these changes result in?
These alteration can result in a less hostile environment that makes it easier for other species to survive. As a consequence, new communities are formed and biodiversity may be changed/increased
Pioneer species often have features that suit them to colonisation.
What are some of these features?
1) sexual behaviour
2) tolerant to?
3) germination periodicity
1) Pioneer species tend to have asexual reproduction so that a single organisms can rapidly multiply to build up a population
2) Pioneer species tend to be tolerant to extreme conditions (extremophiles)
3) Pioneer species have rapid germination of seeds upon arrival as they do not require a period of dormancy
