Populations Flashcards
Abiotic factors
Nonliving chemical and physical factors
Ecology
The scientific study of the interactions between organisms and the environment
Biotic factors
Living factors
Four levels of ecological study
Individuals
Populations
Communities
Ecosystems
How do population biologists determine the number of individuals in a population?
- Census- count every individual
2. Sampling- mark/recapture
Population density?
Why is it important?
- Number of individuals of a species per unit space
2. As density increases, competition for resources increases
What are the three dispersion patterns?
- Clumped- patchy reassures or social interactions. Most common
- Uniform- territorially
- Random- uniform resources. Least common. Trees
What process increases population size?
- Birth
2. Immigration
What process decreases population size?
- Death
2. Moving
Carrying capacity
Number of individuals in a population that the environment can sustain
- More deaths and less births- population decreases