Class #11 - INTRAspecific Population Regulation

Intraspecific

is within a population

interspecific

between different species

Linear

is continous (geometric) where there is a constant growth rate

exponential

is discrete time units and has increasing growth rate

assumptions about the exponential growth model:

• unlimited essential resources

• constant environmental conditions/stable environment

what happens with the resources < replenishments?

Population crash (decrease in population)

Logistic growth

contains a carrying capacity and usually happens during colonization of new species, low density populations in their favorable environments

k

carrying capacity — births = deaths under current environmental conditions. suggest NEGATIVE FEEDBACK.

N=k/2

is the inflection point- where the logisitc curve is growting (population) the fastest.

density-dependence

population regulation affects a population proportion size

density-dependent mortality

density-dependent fecundity

• Increase Pop. density, increase mortality

• Increase Pop. density, Decrease birth

factors elading to density-dependent growth?

• reduced resources

• changes in predaation

• diseases

Density- Independent Regulation

environmental events (ex: floods, storms, fire, etc.)

carrying capacity implies (blank) among individuals within a population

Carrying capacity

Competiton

happens when individuals use a common resource that is limited

Intraspecific competition is among the same species and can cause…

Increased phenotypic plasticity

Intraspecific competition effect:

• decrease in growth and development (leads to density dependent growth)

• higher mortality rates

• decrease in reproduction

Territoriality influences population regulation by…

as population density increases, territories tend to shrink, leading to increased competition for space and resources, ultimately impacting breeding success and restricting population expansion

home range

area an animal uses over the course of a year but does not defend

territory

area an animal uses over the course of a year but does defend

Inverse Density dependence

when a population's growth rate is positively affected by population density

Alle effect

are a small population phenomenon in which population growth rate is reduced by undercrowding

MVP

Minimum viable population

its the number of individuals required to ensure long-term survival of a species