Why Do More Productive Habitats Have Fewer Species? An Experimental Field Investigation

为什么生产力较高的栖息地物种较少？

• 批准号: 8905728
• 负责人: Michael Rosenzweig
• 金额: $ 38万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-15 至 1994-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8905728&HistoricalAwards=false
• 关键词: Why; Do; More; Productive; Habitats

In many environments, the richer the environment, the fewer species it can support. This is true at least in lakes, tropical forest, semi-arid plains and mountainsides, and oceans. It is true of trees and other vegetation, terrestrial mammals, and various kinds of aquatic invertebrates. No general explanation for it has yet been proved. However, preservation of the world's species requires an understanding of the mechanisms which regulates the number of species in natural environments. This research will test two hypotheses in the field. 1) Do other forms of life usurp the resources of a given form as production rises? For example, does the number of mammal species decline because birds and ants take their food? 2) Does the habitat become simpler, costing some specialists their livelihood as production rises? For example, does the variety of architectural forms found among plants diminish, causing the loss of some mammal species? In one set of experiments, the rate at which seeds become available to mammals (but not birds or ants) will be doubled. In another set, in a fairly uniform grassland, the patchiness will be increased by removing small areas of grass. Small mammals will be censused and the natural rate at which they remove seeds from the environment will be measured. Results for this 4-year project will be of immediate interest to basic ecologists as a test of general theory. Findings will also be valuable to scientists developing strategies of bioconservation.

在许多环境中，环境越丰富， 物种可以支持。 至少在湖泊、热带 森林、半干旱平原和山坡以及海洋。 是 树木和其他植物、陆生哺乳动物， 各种水生无脊椎动物。 没有一般性解释 因为它已经被证明了。 然而，保护世界上 物种需要了解其机制， 调节着自然环境中物种的数量。 本研究将验证该领域的两个假设。 1)做 其他形式的生命篡夺资源的一个给定的形式， 产量上升？ 例如，哺乳动物的数量 因为鸟和蚂蚁吃了它们的食物而衰落？ 2)是否 栖息地变得更简单，一些专家的生计成本 随着产量的增加？ 例如， 在植物中发现的建筑形式减少了， 一些哺乳动物物种吗 在一组实验中， 哺乳动物（但不是鸟类或蚂蚁）的可用资源将增加一倍。 在 另一组，在一个相当均匀的草原，斑块将 通过清除小面积的草来增加。 小型哺乳动物 将被普查，它们移除种子的自然速度 将被测量。 这个为期4年的项目将立即取得成果 基本生态学家的兴趣作为一般理论的测试。 这些发现对科学家开发 生物保护战略。