populations and ecosystems Flashcards
(14 cards)
What is a population?
A group of organisms of the same species occupying the same space and can interbreed
What is a community?
Populations of different species
What is the carrying capacity?
An ecosystem supports a certain size of population of a species
What is a niche?
An organism’s adaptation to both biotic and abiotic factors
How do niches benefit an organism?
They can avoid or beat competition
How can population size or abundance be measured?
Using quadrats
How can no bias be ensured?
Random sampling
How can a representative result be ensured?
By using a large number of quadrats
What do transects measure?
The abundance and distribution over an area
What can be measured using a belt transect?
The change in species distribution
How is this done?
By measuring the percentage cover or the frequency of the species can be recorded
How can frequency be measured?
The likelihood of a particular species occurring in a quadrat, number of individuals in a quadrat
How is percentage cover done?
Estimated by eye- proportion of ground area covered by the species
What is the equation for estimated mean density?
Total number of individuals counted / Number of quadrat x area of each quadrat
