population ecology

environmental advocate

works for changes in policy or human behavior to benefit the environment

basic ecology

research on the distribution and abundance of species; how species interact with each other and environment

applied ecology

develop conservation and management plans to limit or repair damage to the ecosystem from human actions

ecology is

describing the distribution and abundance of species

ecology

science that studies the interactions among organisms and their interactions with the environment

populations

same species in the same place at the same time

population attributes

size (N), density (N per unit area), dispersion, demography, genetic characteristics, total fertility rate

size (N)

total number of individuals in an area

dispersion

how they are distributed across the range (uniform, clumped, random)

uniform dispersion

individuals are evenly spaced; influenced by social interactions such as territoriality

clumped dispersion

individuals aggregate in patches

random dispersion

position of each individual is independent of other individuals

properties of demography

births, deaths, immigration, emigration, life tables, survival rate, number of offspring life tables, cohort, generation

type I survivorship curve

high survivorship for juveniles (low death rate), low survivorship for older individuals

type II survivorship curve

uniform survivorship for each age group

type III survivorship curve

low survivorship for juveniles (high death rate), high survivorship for older individuals

fitness trade-offs

individuals have restricted amount of time and energy, and they cannot maximize all physiological aspects

high vs low fecundity

organisms with high fecundity (lots of offspring) tend to grow quickly, reach sexual maturity at a young age, and produce many small eggs or seeds

r=0

no growth

r>1

increasing

r<1

decreasing

rmax

maximum growth rate for a population

exponential growth

density independent, j shaped

logistic growth

density dependent, s shaped

carrying capacity

constrains exponential growth. limit to number of individuals that can occupy a habitat

density dependent factors

resource competition, disease, predation, waste accumulation, social behavior

density independent factors

human disturbances, climate disturbances, disasters, climate change

human carrying capacity

our population will either level off (reduce number of births) or decline (increase number of deaths)

extinction vortex

positive feedback loop (there is change). reduced genetic diversity leads to lower viability and so on