英語考試作文-GRE寫作Issue部分精品素材分享之生物多樣性的指標(biāo)

1、文檔編碼 : CS2R8Q4A7F5 HI7Y6V8Q5W7 ZI9H10M4N3Y2英語考試作文GRE寫作 Issue 部分精品素材共享之生物多 樣性的指標(biāo)想要在 GRE作文部分的考試中寫出優(yōu)秀的文章,論據(jù)素材是重要的一環(huán)；好的論據(jù)不僅能幫忙你支撐觀點(diǎn),加強(qiáng)說服力,仍能表達(dá)出考生在閱讀量上的積存和深厚扎實(shí)的語言功底基礎(chǔ)；特別是 ISSUE作文,更是需要大量好素材作為儲備,才能保證考生無論遭受那種題目, 都能游刃有余地完成一篇高分作文的寫作；為大家整理了 GRE ISSUE作文各類題目的精品優(yōu)質(zhì)素材, 一起來看吧；生物多樣性測量的三大指標(biāo)richness Biodiversity is usu

2、ally plotted as taxonomic of a geographic area, with some reference to a temporal scale. Whittaker described three common metrics used to measure species-level biodiversity, encompassing attention to species richness or species evenness: 1. Species richnessthe least sophisticated of the indices avai

3、lable 2. Simpson index 3. Shannon index There are three other indices which are used by ecologists: 1. Alpha diversity refers to diversity within a particular area, community or ecosystem, and is measured by counting the number of taxa within the ecosystem usually species. 2. Beta diversity is speci

4、es diversity between ecosystems; this involves comparing the number of taxa that are unique to each of the ecosystems. 3. Gamma diversity is a measure of the overall diversity for different ecosystems within a region. 生物多樣性的衡量Biodiversity is a broad concept, so a variety of objective measures have b

5、een created in order to empirically measure biodiversity. Each measure of biodiversity relates to a particular use of the data. For practical conservationists, this measure should quantify a value that is broadly shared among locally affected people. For others, a more economically defensible defini

6、tion should allow the ensuring of continued possibilities for both adaptation and future use by people, assuring environmental sustainability. As a consequence, biologists argue that this measure is likely to be associated with the variety of genes. Since it cannot always be said which genes are mor

7、e likely to prove beneficial, the best choice for conservation is to assure the this persistence of as many genes as possible. For ecologists, latter approach is sometimes considered too restrictive, as it prohibits ecological succession. 生物多樣性與立法Biodiversity is beginning to be evaluated and its evo

8、lution analyzed through observations, inventories, conservation. as well as being taken into account in political and judicial decisions. The relationship between law and ecosystems is very ancient and has consequences for biodiversity. It is related to property rights, both private and public. It can define protection for threatened ecosystems, but also some rights and duties for example, fishing rights, hunting rights. Law regarding species is a more recent issue. It defines species that must be protected because