Chapter 11 Flashcards Preview

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Flashcards in Chapter 11 Deck (31):

intrinsic/existence value

value of an organism, species, ecosystem, or the earth's biodiversity based on its existence, regardless of whether it has any usefulness to us.


instrumental value

value of an organism, species, ecosystem, or the earth's biodiversity based on its usefulness to us.


aesthetic value

is another nonuse value because many people appreciate a tree, forest, wild species, or a vista because of its beauty.


conservation biology

multidisciplinary science created to deal with the crisis of maintaining the genes, species, communities, and ecosystems that make up earth's biological diversity. it's goals are to investigate human impacts on biodiversity and to develop practical approaches to preserving biodiversity.


hot spots

conservation biologists identify the most endangered and species-rich ecosystems.


National Forest System

are used for logging, mining, livestock grazing, farming, oil and gas extraction, recreation, hunting, fishing, and conservation of watershed, soil, and wildlife resources.


National Resource Lands

are used primarily for mining, oil and gas extraction, and livestock grazing.


National Wildlife Refuges

protect habitats and breeding areas for waterfowl and big game to provide a harvestable supply for hunters; a few protect endangered species from extinction. Permitted activities in most refuges include hunting, trapping, fishing, oil and gas development, mining, logging, grazing, some military activities, and farming.


National Park System

only camping, hiking, sport fishing, and boating can take national parks, but sport hunting, mining, and oil gas drilling is allowed.


National Wilderness Preservation System

most of these areas are open only for recreational activities such as hiking, sport fishing, camping, and non motorized boating.


old-growth forest

an uncut forest or regenerated forest that has not been seriously disturbed by human activities or natural disasters for at least several hundred years.


second-growth forest

a stand of trees resulting from secondary ecological succession.


tree plantation/tree farm

site planted with one or only a few tree species in an evened stand. when the stand matures it is usually harvested by clear-cutting and then replanted. these farms normally are used to grow rapidly growing tree species for fuelwood, timber, or pulpwood.


even-aged management

method of forest management in which trees, sometimes of a single species in a given stand, are maintained at about the same age and size and are harvested all at once.


uneven-aged management

method of forest management in which trees of different species in a given stand are maintained at many ages and sizes to permit continuous natural regeneration.


selective cutting

cutting of intermediate-aged, mature, or diseased trees in an uneven-aged forest stand, either singly or in small groups. this encourages the growth of younger trees and maintains an uneven aged stand.


shelterwood cutting

removal of mature, marketable trees in an area in a series of partial cuttings to allow regeneration of a new stance under the partial shade of older trees, which are later removed. Typically, this done by making two or three cuts over a decade.


seed-tree cutting

removal of nearly all trees on a site in one cutting, with a few seed-producing trees left uniformly distributed to regenerate the forest.



method of timber harvesting in which all trees in a forested area are removed in a single cutting.


strip cutting

a variation of clear-cutting in which a strip of trees is clear cut along the contour of the land, with the corridor narrow enough to allow natural regeneration within a few years. after regeneration, another strip is cut above the first, and so one.



removal of trees from a forested area without adequate replanting.


surface fires

forest fire that burns only undergrowth and leaf litter on the forest floor.


crown fires

extremely hot forest fire that burns ground vegetation and treetops.


Healthy Forests Initiative

under this law, timber companies are allowed to cut down economically valuable medium and large trees in most national forests for 10 years in return for clearing away smaller, more fire-prone trees and underbrush.


habitat corridors

can help support more species and allow migration of vertebrates that need large ranges. they also permit migration of individuals and populations when environmental conditions in a reserve deteriorate and help preserve animals that must make seasonal migrations to obtain food.


biosphere reserves

in each of the earth;s 193 biogeographical zones. today there are more than 425 biosphere reserves in 95 countries.


ecological restoration

the process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems.



trying to return a particular degraded habitat or ecosystem to a condition as similar as possible to its natural state.



attempts to turn a degrade ecosystem back into a functional or useful ecosystem without trying to restore it to its original condition.



an abandoned and polluted industrial plant may be cleaned up and then redeveloped into office buildings, apartments, a sports field, or a park.



replacing a degraded ecosystem with another type of ecosystem.