10.3 changes in ecosystems Flashcards
primary succession
- empty inorganic surface (bare rock after volcanic eruption)
- first organisms are called pioneer species (fungi)
- these species penetrate the rock surface and break it into small grains and trap organic material that will break down to form humus
- these form soil and now other species such as grass can establish root systems
- as these plants die and decay it leaves more humus
-eventually animals can live their too and biodiversity increases leading to a climax comunity where range and biodiversity of species is at a constant
secondary succession
- development of an ecosystem from existing soil that is clear of vegetation (wildfires)
- soil contains seeds, roots and soil organisms
what are abiotic factors that have an effect on populations?
- light
- temperature
- wind and water currents
- water availability
- oxygen availability
- soil structure and mineral content
how does light affect populations?
- photosynthesis- influences plant growth unless plants are adapted to low light
- affects circadian rhythms
- reproductive patterns
- availability of food
how does temperature affect populations?
- enzyme activity
- reproduction
how do wind and water currents affect populations?
- wind- used for water loss and cooling down, gales and hurricanes destroy habitats
- water- organisms have to flow with the current
how does water availability affect populations?
- need water to survive unless adapted to low water levels
how does oxygen availability affect populations?
- oxygen nesecary to survive
- problem in stagnant or hot or waterlogged soil
how do edaphic factors affect populations?
edaphic= to do with the soil
- sandy soil: leaches minerals and water passes through quickly/ drains
- clay: gets waterlogged and difficult to drain, hard to work
- loam is the ideal type which is a mixture
what are biotic factors that affect populations?
- predation
- finding a mate
- territory
- parasitism/disease
how does predation affect populations?
- predator/pray populations oscillate
how does finding a mate affect populations?
- lack of species in the area
- cannot find a mate to reproduce
how does territory affect populations?
- necessary so breeding paris have sufficient resouces to raise their young
how does paraticism/disease affect populations?
- affects survival/reproductive success
what is intraspecific competition?
competition between members of the same species for a limited resource
