生物多样性论文文献

Biodiversity is an important theme in biology and is crucial to theprosperity and survival of humans. The benefits that ecosystems andindividual species provide to humans are countless: clean air andwater, detoxification and decomposition of wastes, preservation offertile soils, control of agricultural pests, aesthetic beauty,(Campbell & Reece, 2002) and many more. Moreover, biodiversity iscommonly studied to view community structure and the health of aparticular region. Species richness and abundance values can helpbiologists address certain environmental concerns and possiblesolutions to issues they may find. Bio Science 1 students at SolanoCommunity College often conduct studies of freshwatermacroinvertebrates in Suisun Creek to view biodiversity and todetermine water quality. The upstream and downstream sites rests onprivate property identified to the students only as �0�0“Frank�0�0’s Place�0�0”.The settings of the Suisun Creek sites were both overwhelmed withvegetation and overhead canopies. Timing of sampling is directlyrelated to the resulting collected species. Species diversity indices,such as Family-level biotic Index, are used to provide importantinformation on the community structure of freshwatermacroinvertebrates and can often tell us the overall health of theregion we are studying also FBI provides a rapid, but less critical,evaluation of streams in the field by biologists who can recognizearthropod families by sight.[2] The non-living, abiotic componentsthat the class attempted to research at all three stream locationsincluded taking readings of the water's: temperature (oC), dissolvedoxygen [% saturation and (mg/l)], conductivity (�0�0�0�8S), specificconductance (�0�0�0�8S), salinity (ppt), and pH. Dissolved oxygen is ameasured value of the oxygen content that is present in the water.

Biological diversity means the variety of living within a certain range of organisms regularly posed by combining the ecological complexes of stability. Including such diverse animals, plants, micro-organisms of the species diversity, species diversity and variation of genetic and ecosystem diversity. Among them, the species diversity is the key to biological diversity, it reflects the biological and the environment between the complex relationship between, but also reflects the richness of biological resources. We now know that there are about two million kinds of organisms, these kinds of biological species constitute the diversity of biological species. Biological diversity is the formation of organisms and their ecology and the environment as well as the complex range of ecological processes related to the sum of genetic diversity, species diversity and ecosystem diversity components. Genetic diversity refers to the body decided to biological traits and combinations of genetic diversity. Species diversity is the diversity of species on biological manifestations can be divided into regional species diversity and species diversity of communities. Ecosystem diversity refers to the biosphere habitats, communities and ecological processes of biological diversity. Genetic diversity and species diversity is the basis of the study of biological diversity, ecosystem diversity is the focus of the study of biological diversity. Was asked, based on the study of nature can be inferred What are the characteristics of the work of the Creator, is said to British scientists Sanderson Haldane John Leighton replied: "too much like beetles." Because the beetle is the largest animal on Earth group.Telloy the United States the text of the Smithsonian Institution concluded that the majority of unknown types of beetles may not be able to survive in our near 30-meter-high canopy of tropical forests.

陆地和海洋中存在着无数的植物、动物和微生物。他们使这个世界变的完美：将阳光转化为能量，供给其它生物，并使碳和氮在无机和有机两种形式之间转化，改变着地球的景观。 在一些地方和一些群落中，存在着成百上千的物种，然而在其它地方和群落中，只有很少的物种存在。例如，比起高纬度地区，热带是一个物种的天堂。生物学家试图阐明这其中的原因。环境和生物的相互作用，生物之间的关系在增加或者降低生物多样性方面起了关键作用。人类的干扰，捕食者－猎物之间的关系和其它的食物链上的关系也起到了一定作用。但是，这些因素和其它的力量到底如何共同作用形成了多样性？这至今是个迷。 这是一个挑战，因为我们缺少最基本的数据。例如，我们至今不知道地球上到底存在多少植物和动物。研究者甚至还不能开始预测微生物的种类和数目。研究进化的科学家也缺少一个标准的时间尺度，因为进化的发生会从几天持续到几百万年。而且，同一个物种内的变化会跟两个相近物种之间的变化几乎相同。我们也不清楚什么样的基因变化会导致一个新物种的产生，基因对物种形成的真正影响到底是什么。 揭示多样性形成的原因需要全面的跨学科的合作，包括古生物学的提示，实地的考察，实验室的工作，基因组的比较和有效的数据分析。一些大的项目，比如联合国千年计划和世界范围内海洋微生物基因的鉴定，将增加基础的数据，但这些是远远不够的。预测一个物种如何分裂成两个物种的模型将会有一定的帮助。一个研究基因在发育进化中作用的新学科——“进化发育生物学”（evolutionary developmental biology，evo-devo）出现。所有的这些努力，在阐明生命的历史上仍有一段很远的路要走。 古生物学家已经在跟踪许多物种过去一千年内分布和聚集方面取得了一些成果。他们发现，地理分布在物种形成中起了重要作用。进一步的研究将继续揭示大范围的物种分布模式，这或许将对阐明大灭绝的原因和研究这些灾难对新物种的进化的作用带来希望。 通过对植物和动物的实地考察，研究者已经知道生境（habitat）能够以加速或减慢物种形成的方式影响表型和行为——尤其是性选择。进化生物学家也发现物种形成过程会中断，例如，当分离的种群重新结合时，基因组会被匀质化（否则就会分化）。分子水平的力量，例如低的突变速率或者减数分裂的驱动——这些情况下特定的等位基因更可能从亲代传到子代——影响了物种形成的速率。 在一些情况下，一个生态系统内的多样性会发生变化：生态系统的边缘的物种多样性有时比中部更低。 对不同的生物群体，这些因素如何以不同的方式相互作用？进化生物学家的研究才刚刚开始。任务是严峻的：阐明多样性形成的原因对理解地球上正在发生的物种灭绝的本质和找到缓解的手段有非常重要的作用。 你对生物多样性有什么认识？欢迎参与经纬论坛中的相关讨论。