Dissertation Research: Investigations of the Relationship Between Biodiversity and Ecosystem Function by Examination of Acidified Streams

虽然生物多样性一直是许多生态学研究和保护工作的焦点，但其与生态系统功能的关系仍未得到解决。文献提供了生物多样性和生态系统功能之间相互依赖和独立的例子。本研究的目的是验证以下三个假设：(1)在一个增量压力的生态系统中，给定的生物室首先表现为生物多样性的抑制，然后是生物量的抑制；(2)生态系统功能的抑制主要与生物量的抑制有关，而与生物多样性本身无关；(3)根据一系列可预测的阈值，不同生物区室对生物量的抑制不同：多细胞生物单细胞自养微生物分解者。这些假设将在一组溪流上进行测试，其中一些已经受到酸性矿井排水的压力。这些流是优秀的模型系统，因为它们包括多种应力（低pH值，高浓度金属，氧化物沉积）的宽梯度，每一个都是可量化的。对这些河流的初步研究与这三个假设是一致的。该项目将侧重于扩大关于底栖昆虫和周围植物的资料，以检验这些假设，并利用分子技术获得关于微生物分解者室的可比资料。

9701332 Lewis While biodiversity continues to be the focus of many ecological studies and conservation efforts, its relation to ecosystem function remains unresolved. The literature provides examples of both interdependence and independence between biodiversity and functioning of ecosystems. The purpose of this project is to test three hypotheses, as follows: (1) a given biotic compartment in an incrementally stressed ecosystem will show suppression of biodiversity first, and suppression of biomass subsequently; (2) suppression of ecosystem function is primarily related to suppression of biomass, rather than to biodiversity per se; and (3) suppression of biomass differs among biotic compartments according to a predictable series of thresholds: multicellular organisms unicellular autotrophs microbial decomposers. These hypotheses will be tested on a group of streams, some of which have been stressed by acidic mine drainage. These streams are excellent model systems because they include a wide gradient of multiple stresses (low pH, high concentration of metals, oxide deposition), each of which is quantifiable. Pilot studies on these streams are consistent with the three hypotheses. The project will focus on expansion of the information on benthic insects and periphyton as necessary to test the hypotheses, and use of molecular techniques to obtain comparable information on microbial decomposer compartments.