Populations in Ecosystems: Variation in Populatioon Size

An ecosystem can support a specified population size of a species, known as carrying capacity.
Population size can fluctuate due to abiotic factors and organism interactions including competition and predation.
For estimating population sizes:
- Quadrats, randomly placed or along a belt transect, can be used for slow-moving or non-moving organisms.
- The mark-release-recapture method can be used for motile organisms, though certain assumptions are made in this method.
Ecosystems are dynamic, which implies impacts on food chains and predator-prey relationships.
It is important to understand the various factors that impact population and be able to compose an appropriate method to calculate population size in a specific area or for a certain species.