Herbivory in Streams: Context-dependent Species Interactions and Functional Redundancy

这个项目将调查移动的草食动物(食草动物)调节自养群落(例如藻类)的结构和功能的能力，以及这种关系如何随着环境条件的变化而变化。研究方法是阐明在一系列物理条件下草食动物物种之间相互作用的潜在结果的机制。在溪流中觅食底部群落的食草动物将被包括在一系列实验中，通过这些实验，主导的环境梯度(水流速度)将被改变。实验将评估环境梯度上的自养生物量积累和群落组成，以及放牧物种在调节藻类群落方面的功能冗余。这些实验方法被很好地结合在一起，这样就有可能扩大实验规模，并在不同的环境条件下对多物种食草动物的规模进行机械预测。这项研究的结果可以推广到其他在物理条件上具有空间异质性和具有多种草食物种的生态系统。此外，这项研究对于理解消费者的共存以及物种之间的“冗余”或“可替代”程度具有重要意义。这种理解对于支持成功恢复溪流和河流生态系统至关重要。

0075352PoffThis project will investigate the ability of mobile herbivores (grazers) to regulate the structure and function of the autotrophic community (e.g., algae), and how this relationship varies with changing environmental conditions. The research approach is to elucidate the mechanisms underlying the outcomes of interactions among herbivore species under a range of physical conditions. Herbivores that graze bottom communities in streams will be included in a series of experiments whereby the dominant environmental gradient (current velocity) is altered. Experiments will assess autotrophic biomass accumulation and community composition across the environmental gradient, as well as the functional redundancy among grazer species in regulating algal communities. The experimental approaches are well integrated so that it will be possible to scale-up experiments and make mechanistic predictions about the magnitude of multi-species herbivory under variable environmental conditions. Results of this study may extend to other ecosystems with spatial heterogeneity in physical conditions and with a variety of herbivorous species. Moreover, the research has significant implications for understanding co-existence of consumers and the degree of "redundancy" or "substitutability" among species. Such understanding is critical for supporting successful restoration of stream and river ecosystems.