Week 8: Ecological succession Flashcards
Do the abiotic and biotic components of an ecosystem change regularly?
yes these changes alter the makeup of the community. May also alter the range over which it is found.
The size of populations of many species varies over the
seasons.
Long-term change to ecosystems occurs if the abiotic and biotic components of the ecosystem are
significantly altered.
What can cause long term changes to an ecosystem?
Events such as natural disasters, human activities and the colonisation of new species
Long term changes can result in the ecosystem being unable to support
existing collections of species in favour of different organisms.
Ecological succession
change in a mix of species that happen in an ecosystem over time
Succession occurs in a __________ manner.
undirectional
two types of succession;
primary succession and secondary succession.
Primary succession is an unidirectional process through which a .
lifeless ecosystem turns into a stable community of living species. Occurs in lifeless areas.
Uses pioneer or colonising species that alter the abiotic conditions of the ecosystem.
Pioneer species are
autotrophic organisms such as lichen and mosses.
that possess characteristics like the ability to fix nitrogen, reproduce rapidly and tolerate harsh conditions.
Pioneers inhabit the area when their
spores are blown into the area by the wind.
As these populations of pioneer species grow and die
their remains and tiny pieces of eroded rock form simple soils
