chapter 9
background extinction rate
Normal extinction of various species as a result of changes in local environmental conditions.
endangered species
A species whose numbers are so small that the species is at risk of extinction.
biodiversity hotspots
areas especially rich in plant species that are found nowhere else and are in great danger of extinction
old-growth forest
an uncut or regenerated primary forest that has not been seriously disturbed by human activities or natural disasters for 200 years or more
urban sprawl
Urbanized areas that spread into rural areas, removing clear boundaries between the two
threatened species
wild species that is still abundant in its natural range but is likely to become endangered because of a decline in its numbers
endangered species act
(ESA) designed to identify and protect endangered species in the US and abroad. Some believe the ESA should be weakened or repealed, and others believe it should be strengthened and modified to focus on protecting ecosystems
overgrazing
occurs when too many animals graze for too long and exceed the carrying capacity of a rangeland area; reduces grass cover, exposes the soil to erosion by water
second-growth forest
a stand of trees resulting from secondary ecological succession
zoning
a planning tool used to separate industry and buisiness form residential neighborhoods
biological extinction
complete disappearance of a species from earth
habitat fragmentation
Occurs when a large, contiguous area of habitat is reduced in an area and is divided into smaller, more scattered, and isolated patches, or habitat islands. This process threatens many species by decreasing tree populations in forests, block migration routes, and divide populations of a species into small and more isolated groups that are more vulnerable to predators, competition, disease, and catastrophic event
ecological restoration
returning a particular degraded habitat to a condition as similar as possible to its natural state
smart- growth
a set of principles for community planning that focuses on strategies to encourage the development of sustainable healthy communities
clear cutting
A method of harvesting trees that involves removing all or almost all of the trees within an area
HIPPCO
Habitat, Invasive, Population, Pollution, Climate Change, Overexploitation
biodiversity hotspot
an area especially rich in plant species that are found nowhere else and are in great danger of extinction.
reconciliation ecology
working together, compromising, finding ways to share land; inventing, establishing and maintaining new habitats to conserve species diversity in places where people live, work, or play
selective cutting
The method of harvesting trees that involves the removal of single trees or a relatively small number of trees from among many in a forest
urban heat island
An urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities
biomagnification
an increase in the concentration of a chemical in organisms at successively higher trophic levels of a food chain or food web
mass extinction
a catastrophic widespread, often global event in which major groups of species are wiped out over a short time compared with normal background extinction
rangelands
unfenced grasslands in temperate and tropical climates that supply vegetation for grazing or browsing animals
tree plantation
A large area typically planted with a single rapidly growing tree species
tragedy of the commons
The tendency of a shared limited resource to become depleted because people act from self-interest for short-term gain