3.7.3 Populations and Ecosystems Flashcards
Why is it important to measure species diversity?
to compare different habitats or study how a habitat has changed over time
Define niche
The role of a species in it’s environment
Define community
All of the organisms of different species that live in the same habitat and interact with each other
Define population
All the organisms of one species in a habitat
Define mutualism
A relationship between two organisms where both benefit
Define ‘population size’
The number of individuals of one species in a particular area
Define ecosystem
All the organisms living in a particular area and all the non living (abiotic) factors
Define habitat
The place where an organism lives
Define species distribution
Where a species is within a particular area
Define abundance
The number of individuals of one species in a particular area
Define biotic factors
The living features of the ecosystem (e.g. predators, prey, microorganisms)
Define abiotic factors
The non living features of the ecosystem
Define carrying capacity
The maximum stable population size of a species
What happens as a population of organisms approaches carrying capacity (k strategist)
Density dependent factors limit the rate of population growth (eg availability of food). This is sometimes referred to as environmental resistance
How can some organism have a polulation above carrying capacity
They reproduce very quickly (often small organisms - R strategists) and a population boom will be followed by a bust (dramatic decrease).