Population density
number of individuals per unit area
Age structure
the number of males and females of each age group that a population contains
Immigration
movement of individuals into an area occupied by an existing population
Emigration
movement of individuals out of an area
Exponential growth
growth pattern in which the individuals in a population reproduce at an increasing rate
Logistic growth
growth pattern in which a populations growth slows and the stops following a period of exponential growth
Carrying capacity
largest number of individuals of a particular species that a particular environment can support
Limiting factor
factor that causes population growth to decrease
Density-dependent limiting factor
limiting factor that depends on population density
Density-independent limiting factor
limiting factor that affects all populations in similar ways regardless of the population density.
Demography
scientific study of human populations
Demographic transition
change in a population from high birth and death rates to low birth and death rates
Biological magnification
Increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain or food web
aquaculture
raising of aquatic organisms for human consumption
ecological footprint
Total amount of functioning ecosystem needed both to provide the resources a human uses and to absorb the wastes that a population generates
ecological hot spot
Small geographic area where a significant number of habitats and species are in immediate danger of extinction
acid rain
precipitation containing nitric and sulfuric acids.
biodiversity
total of the variety of organisms in the biosphere
habitat fragmentation
splitting of ecosystems into pieces
ozone layer
Atmospheric layer in which ozone gas is relatively concentrated; protects life on earth from UV rays in sunlight
genetic diversity
Sum total of all different forms of genetic information carried by a particular species, or by all organisms on Earth
species diversity
number of different species that make up a particular area
smog
gray-brown haze formed by a mixture of chemicals
Sustainable Development
Strategy for using natural resources without depleting them and for providing human needs without causing long-term environmental harm