Populations Inna Ecosystem Flashcards
(16 cards)
What is a community
All the populations of Diffrent species living in the same habitat
What is an ecosystem
A community and the non-living (abiotic) components of its environment
What is a niche
The specific role of a species within its habitat
Governed by its adaptation to both abiotic and biotic conditions
Advantages of many niches
Less competition for food
What is the carrying capacity
Max sustainable pop of a species that an ecosystem can support
Factors that influence carrying capacity
Abiotic:
-light
-temp
-humidity
-etc
Biotic:
-interspecies competition (different species)
-intraspecies competition (same species)
-predation
How can abiotic factors affect carrying capacity
If condition favour an organism they will be more likely to survive and reproduce - increasing carrying capacity
E.g. increasing light means more photosynthesis so increase in carrying capacity in plants and then increasing the carrying capacity of animals
How can interspecies competition affect pop size
Reduces resource absolve to both species so limits their chance of survival and reproduction
So decline in both pop sizes
Is 1 species is better adapted they will outcompete
How can intraspecies competition affect pop size
As pop size increase resources decrease so competition increases
So chances of survival and reproduction decreased- pop size decreases
As pop size decreases resources become available, competition decreases
Survival and reproduction increases - pop size increases
Changes wich occur in pops of predation and prey
Prey increase sos predators increase
They kill to much prey so prey pop decreases
Less prey so predation pop decreases
Prey pop increases
Mark and releases method
Capture sample of species, mark and release them
Ensure marking dosent affect survival
Allow time for organisms to distribute themselves
Collect 2nd sample
Pop= no in sample 1 X no I’m sample 2
Divide by
Number marked in sample 2
What is succession
Change in a community over time due to a change in abiotic factors/species
Primary succession
Colonisation by pioneer species (lichen)
They change abiotic factors (they die increasing soil nutrients)
So environment becomes less hostile and more suitable for other species
As this goes on biodiversity increases
Climax community recurs - findable stable community (no more succession)
Features of a climax community
Same species present over a long time
Stable community over a long time
Abiotic factors constant
Populations fairly stable
How conservation of habitats involves management of succession
Succession can be prevented to stop a climax community forming (removing or preventing growth, allowing grazing)
This preserves the ecosystem at a point in secession
Early species aren’t outcompeted and habitats/niches not lost
Conflict between humans needs and conservation
Human demand for resources leads to habitat destruction
Conservation is needed to pretext these habitats
Management of this maintains sustainability of natural resources
