Chapter 55 Flashcards
biodiversity
The richness of living systems as reflected in genetic variability within and among species, the number of species living on Earth, and the variety of communities and ecosystems.
desertification
A process in which large tracts of subtropical forest are cleared and overused, the groundwater table recedes to deeper levels, less surface water is available for plants, soil accumulates high concentrations of salts, and topsoil is eroded by wind and water.
overexploitation
The excessive harvesting of an animal or plant species, potentially leading to its extinction.
habitat fragmentation
A process in which remaining areas of intact habitat are reduced to small, isolated patches.
edge effects
A phenomenon in which the removal of natural vegetation disrupts the local physical environment, exposing the borders of the remaining habitat to additional sunlight, wind, and rainfall.
invasive species
A nonnative species that can occupy a wide range of habitats and competitively exclude native species from those habitats.
biodiversity hotspots
An area where biodiversity is both highly concentrated and endangered.
endemic
A species that occurs in only one place on Earth.
conservation biology
A interdisciplinary science that focuses on the maintenance and preservation of biodiversity.
population viability analysis
A mathematical analysis used by conservation biologists to determine the minimum viable population size for threatened or endangered species.
minimum viable population size
The smallest population size that is likely to survive both predictable and unpredictable environmental variation.
landscape ecology
The field that examines how large-scale ecological factors—such as the distribution of plants, topography, and human activity—influence local populations and communities.
ecosystem valuation
A process in which ecosystem services are assigned an economic value.
hydrologic alterations
Human-induced changed in the pathways through which water moves in the hydrologic cycle.
pollutants
Materials or energy in a form or quantity that organisms do not usually encounter.
acid precipitation
Rainfall with low pH, primarily created when gaseous sulfur dioxide (SO2) dissolves in water vapor in the atmosphere, forming sulfuric acid.
ecosystem services
The ecological processes on which all life depends, which include decomposition of wastes, nutrient recycling, oxygen production, maintenance of fertile topsoil, and air and water purification.
endangered
A species in danger of extinction throughout all or a significant portion of its range.
The maximum size of a population that an environment can support indefinitely.
carrying capacity
An activity in which visitors, often from wealthy countries, pay a fee to visit a nature preserve.
ecotourism
