| 单词 | biodiversity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 | biodiversitybi·o·di·ver·si·tyB0261875 (bī′ō-dĭ-vûr′sĭ-tē)biodiversity(ˌbaɪəʊdaɪˈvɜːsɪtɪ)bi•o•di•ver•si•ty(ˌbaɪ oʊ dɪˈvɜr sɪ ti, -daɪ-)n. bi·o·di·ver·si·ty(bī′ō-dĭ-vûr′sĭ-tē)biodiversity
biodiversitybiodiversity:see biological diversitybiological diversityor biodiversity, the number of species in a given habitat. Scientists have variously estimated that there are from 3 to 30 million extant species, of which 2. ..... Click the link for more information. . BiodiversityThe variety of all living things; a contraction of biological diversity. Biodiversity can be measured on many biological levels ranging from genetic diversity within a species to the variety of ecosystems on Earth, but the term most commonly refers to the number of different species in a defined area.
Recent estimates of the total number of species range from 7 to 20 million, of which only about 1.75 million species have been scientifically described. The best-studied groups include plants and vertebrates (phylum Chordata), whereas poorly described groups include fungi, nematodes, and arthropods (see table). Species that live in the ocean and in soils remain poorly known. For most groups of species, there is a gradient of increasing diversity from the Poles to the Equator, and the vast majority of species are concentrated in the tropical and subtropical regions. Human activities, such as direct harvesting of species, introduction of alien species, habitat destruction, and various forms of habitat degradation (including environmental pollution), have caused dramatic losses of biodiversity; current extinction rates are estimated to be 100–1000 times higher than prehuman extinction rates. Some measure of biodiversity is responsible for providing essential functions and services that directly improve human life. For example, many medicines, clothing fibers, and industrial products and the vast majority of foods are derived from naturally occurring species. In addition, species are the key working parts of natural ecosystems. They are responsible for maintenance of the gaseous composition of the atmosphere, regulation of the global climate, generation and maintenance of soils, recycling of nutrients and waste products, and biological control of pest species. Ecosystems surely would not function if all species were lost, although it is unclear just how many species are necessary for an ecosystem to function properly. Biodiversitybiodiversity[‚bī·ō·di′vər·sə·dē]biodiversitywww.biosis.org.uk/zrdocs/zoolinfo/biodiv.htm www.eti.uva.nl www.biodiv.org biodiversitybiodiversity(bī′ō-dĭ-vûr′sĭ-tē)biodiversityThe existence of complex flora and fauna in an ecosystem; the genetic diversity of natural organisms. Biodiversity increases the overall productivity of a plot of land, and maximises its resistance to disturbances—e.g., drought. In prairie ecosystems stressed by drought, recovery to a normal state of productivity was more rapid in experimental plots of vegetation with the greatest biodiversity, a finding that supports the need to maintain biodiversity.Loss of biodiversity—i.e., a reduction in the number of species, subspecies and strains—will be disastrous for the planet's ecosystem. An example would be growing a crop food, e.g., corn or rice, from only one highly productive, rapid-growing, spoil-resistant strain—while seemingly having all the desirable features, if the strain became susceptible to a particular pathogen, all those dependent on the crop could face famine. Marine biodiversity may be in a state of ecological crisis due to coastal development—e.g., destruction of estuaries, motorised marine vessels, ocean dumping, oil spills, overfishing with trawling of the ocean floor and subsequent disruption of bottom communities and coral reefs, overwhaling, pollutant runoffs, and toxic tides due to eutrophication. biodiversitysee DIVERSITY.biodiversitybiodiversitythe variety of plant and animal life in a particular area. Environmentalists have expressed concern about the extent to which ECONOMIC GROWTH, in particular modern methods of farming, forestry and manufacturing, has reduced biodiversity, with some plant and animal species becoming rare or extinct. See POLLUTION.biodiversity
Words related to biodiversity
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英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。
biodiversity - the diversity of plant and animal life in a particular habitat (or in the world as a whole); "a high level of biodiversity is desirable"