Effects of Algal Diversity on the Productivity of Streams: Does Diversity Play a Greater Role in Variable vs. Constant Environments?

在过去的十年中，越来越多的研究通过实验减少了群落中的物种数量，并研究了多样性丧失如何影响重要的生态系统过程，如初级生产。研究通常是在实验控制最大化的简单环境中进行的，在这些条件下，结果表明维持生态系统生产力所需的物种相对较少。但是，这个结论在空间和时间异质性普遍存在的更自然的栖息地中是否成立？还是需要更多的物种才能在复杂多变的环境中保持生产力？本项目采用实证方法，利用淡水藻类模型系统来解决这些问题。将进行实地和实验室实验，以比较藻类多样性如何影响具有简化流量制度的河流生态系统的初级生产，以及在流量中表现出明显的时空变化的更自然的系统。全球生物多样性的丧失是我们这个时代普遍存在的环境变化之一。虽然我们了解物种灭绝的主要原因，但对物种灭绝对环境的影响知之甚少。这项研究的目的是确定哪种类型的生态系统对物种损失最敏感。

Over the past decade, an increasing number of studies have experimentally reduced the number of species in a community and examined how diversity loss impacts important ecosystem processes such as primary production. Studies have generally been performed in simple environments that maximize experimental control, and under these conditions, results suggest that relatively few species are needed to maintain ecosystem productivity. But would this conclusion hold true in more natural habitats where spatial and temporal heterogeneity are pervasive? Or would a greater number of species be required to maintain productivity in complex environments that are inherently variable? This project takes an empirical approach to address these questions using a model system of freshwater algae. Field and laboratory experiments will be performed to compare how algal diversity impacts primary production in stream ecosystems that have simplified flow regimes, to more natural systems that exhibit pronounced spatial and temporal variation in flow. Global loss of biodiversity ranks among the pervasive environmental changes of our time. Although we understand the primary causes of extinction, much less is known about the environmental impacts of extinction. The goal of this research is to determine which types of ecosystems are most sensitive to species loss.