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

9701332刘易斯虽然生物多样性仍然是许多生态研究和保护工作的重点，但它与生态系统功能的关系仍未解决。这些文献提供了生物多样性和生态系统功能之间相互依存和相互独立的例子。本项目的目的是检验以下三个假设：(1)在递增压力下的生态系统中，给定的生物舱将首先表现出生物多样性的抑制，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，而不是生物多样性本身；(3)生物量的抑制根据一系列可预测的阈值而不同：多细胞生物体、单细胞自养生物、微生物分解者。这些假设将在一组溪流上进行测试，其中一些溪流受到酸性矿山废水的影响。这些流是很好的模型系统，因为它们包括多种压力的宽梯度(低pH值、高金属浓度、氧化物沉积)，每一种压力都是可以量化的。对这些河流的初步研究与这三个假设是一致的。该项目将侧重于在必要时扩大关于底栖昆虫和附生植物的信息，以检验假设，并利用分子技术获得关于微生物分解物舱的可比信息。

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.