wiki

cards are here

Population Ecology

$ What is a population?

A group of individuals of a single species living in same general read

$ What is population density?

(density = \frac{# individuals}{area})

Patterns of Dispersal

How populations are spaced out

$ What is random dispersal?

Unpredicatable spacing, not as commin in nature

$ What is uniform dispersal?

Usually antagonistic interactions, all organisms are equadistant

$ What is clumped dispersal?

Organisms are clumped together, with large amounts of space between clumps

Survivorship Curves

$ What are survivorship curves?

A graph that indicates the proportion of offspring born to those that actually survive.

K and r selected species

K selected species

$ What are k selected species?

The are large in size. Sexual maturity is later in life. Produce few, large, immature offspring. Offspring receive lots of perantal care. Intraspecific competition is high.

r selected species

$ What are r selected species?

The opposite of k selection. Organisms are small in size. Early sexual maturity. Produce large numbers of small mature offspring. Little parental care. Intraspecific competition is low.

Population Growth

$ What types of population growth is there?

Exponential and logistical growth

Exponential Growth

$ What conditions create exponential growth?

Unlimited resources. No predators. No competition

$ What is the formula for exponential population growth?

(\frac{dN}{dT}=B-D=r_max N), Change in number over change in time = Births - deaths = Per capita rate of increase x number of individuals.
Represents unrestrained growth, does not account for carrying capacity.

Logistical Growth

$ What is carrying capacity?

The max number of individuals and environment can support

$ What is the formula for logistic growth?

(\frac{dN}{dT}=r_max(\frac{K-N}{K})). Change in number over change in time = per capita rate of increase * the unused portion of carrying capacity.

Limiting factors

$ What are limiting factors?

Constraints that prevent a population from reaching maximum growth. Limited space, food, etc

Density-Dependent factors:

Population matters

$ What are density-dependent factors?

Any biotic limiting factors. Competition, diseases.

Density-Independent factors:

Population does not matter

$ What are density-independent factors?

Any abiotic limiting factors. Natural disasters, hurricanes, flood.