DISSERTATION RESEARCH: Fish assemblage structure and functional trait diversity along a longitudinal fluvial gradient

了解环境因素如何与生态群落中生物体的特征相关，有助于揭示推动多样性模式的重要过程。 功能性状与喂养，栖息地的使用，或繁殖可以检查沿着环境梯度调查栖息地变量如何影响群落组成在多个空间尺度。 在这项研究中，这样的方法将被用来比较鱼类群落沿着纵向梯度在里奥Grijalva，在墨西哥南部的一个大型热带河流流域。 鱼类的功能特性将被检查沿着与一套环境变量在研究地点在一系列的栖息地，从高地支流广泛，低地泻湖。 随着栖息地环境变得不那么恶劣，食物资源更加丰富，预计从上游到下游的性状的多样性将增加，这项研究对本研究区域和其他热带河流的保护具有重要意义。 很少有研究在整个流域的尺度上研究热带鱼群落的变化，对环境差异如何影响功能性状知之甚少。 关注环境因素如何影响鱼类群落将为评估物种引进、蓄水和其他形式的栖息地退化的影响提供有价值的信息。

An understanding of how environmental factors relate to the characteristics of organisms in ecological communities can help reveal important processes driving patterns of diversity. Functional traits associated with feeding, habitat use, or reproduction can be examined along environmental gradients to investigate how habitat variables influence community composition at multiple spatial scales. In this study, such an approach will be used to compare fish communities along a longitudinal gradient in the Río Grijalva, a large tropical river basin in southern Mexico. Functional traits of fishes will be examined along with a suite of environmental variables in study sites across a range of habitats, from upland tributary streams to broad, lowland lagoons. The diversity of traits is expected to increase from upstream to downstream as habitats become less environmentally harsh and food resources are more plentiful.This research has important implications for conservation in this study region and in other tropical rivers. Few studies have examined changes in tropical fish communities at the scale of an entire watershed, and little is known about how environmental differences affect functional traits. A focus on how environmental factors influence fish communities will provide valuable information for evaluating the effects of species introductions, impoundments, and other forms of habitat degradation.