Ecology

Matthew Cabrera - AP Bio

Biogeochemical cycles

pathways that recycle water and essential chemical elements between living organisms and the environment

ecology

the study of how organisms interact with each other and with their environment

decomposers

organisms such as fungi and bacteria that break down dead organic matter and recycle nutrients

abiotic

the nonliving physical and chemical parts of an environment

consumers

organisms that obtain energy by eating other organisms or organic matter

biotic

the living components of an environment

producers

autotrophs that make their own organic food

population

a group of individuals of the same species living in the same area

density dependent

describing limiting factors whose effects increase as population density increases

community

all the populations of different species living and interacting in an area

r-strategists

species that produce many offspring quickly with little parental care

ecosystem

a biological community plus all the abiotic factors with which it interacts

k-strategists

species that produce fewer offspring and invest more energy in growth and parental care

biosphere

the global sum of all Earth’s ecosystems; all regions where life exists

carrying capacity

the maximum population size an environment can sustainably support

dispersal (dispersion)

the pattern of spacing of individuals within the area a population inhabits

exponential population growth

rapid population increase under ideal conditions in which growth rate stays proportional to size

climate

long-term prevailing weather conditions in an area

demography

the study of factors that affect population size

niche

an organism’s ecological role and the sum of its use of biotic and abiotic resources

emigration

movement of individuals out of a population

mutualism

a symbiotic relationship in which both species benefit

immigration

movement of individuals into a population

parasitism

a symbiotic relationship in which one organism benefits while the host is harmed

population ecology

the study of how populations interact with the environment and change over time

commensalism

a symbiotic relationship in which one species benefits and the other is neither helped nor harmed

ecological succession

the gradual change in community composition following a disturbance or the formation of new habitat

species diversity

the variety of species in a community

biomass

the total mass of living organic matter in a given area or trophic level

trophic structure

the feeding relationships in an ecosystem that determine energy flow and chemical cycling

food webs

networks of interconnected food chains showing feeding relationships in an ecosystem