Chapter 14 Flashcards
Human population growth, disease, and food supply
Demographic transition
A switch from high birth and death rates to low birth and death rates.
Emerging infectious disease
Diseases appearing in the human population for the first time or expanding rapidly.
Zoonoses
Infections that circulate naturally in nonhuman vertebrate hosts but can be transmitted from these to humans.
Pest
Any species that causes economic damage (usually in agriculture).
Economic injury level (EIL)
The population level at which further reduction of a pest would cost more than we would gain in improved yield of a crop.
Monoculture
Farming resources as dense populations of a single species.
Biomagnification
The increased concentration of toxins in an organism as a result of ingesting other plants or animals in which the toxins are more widely disbursed.
Target pest resurgence
Treatment kills large numbers of the pest and its natural enemies. Pest individuals that survive the pesticide have more resources and few predators.
Biological control
Controlling a pest by manipulating its natural enemies.
Desertification
Land that is arid or semiarid but has supported natural ecosystems, gives way to desert.
Salinization
Buildup of salts in soil, eventually to toxic levels for plants. Can spread and leads to white salt deserts.
Biofuels
Sources of energy developed from biomass derived from agriculture or natural ecosystems.
Aquaculture
Farming of aquatic plants and animals.
Maximum sustainable yield (MSY)
The maximum level at which a natural resource can be routinely exploited without long-term depletion (e.g. used in fishing and forestry).
Fixed quota
Method to obtain MSY. Remove the same amount (the MSY) from the population every year.
