DISSERTATION RESEARCH: FORECASTING GLOBAL WARMING EFFECTS ON DEVELOPMENTAL PERFORMANCE OF PRAIRIE STREAM FISHES ALONG THE RIVER CONTINUUM

预测物种在景观中的位置是生态学的一个基本方面，也是保护生物多样性的重要步骤。环境生态位模型是预测物种分布的常用工具，但对物种发生或丰度与环境变量之间因果关系的理解有限，限制了这些模型的普遍性。提高对个体表现如何沿着环境梯度变化的理解对于开发基于机械的环境生态位模型是必要的。本研究的动机是观察到许多河流鱼类的分布沿河流大小梯度变化，但对河流大小与物种分布之间的机制关系知之甚少。该项目将开发生态位模型来预测流经美国中部弗林特山的溪流中鱼类的分布，弗林特山从源头到大河表现出强烈的温度梯度。考虑到温度作为一个环境因素的普遍重要性，它限制了个体的代谢、生存和生长速率以及种群的生命速率，我们预测温度依赖的性能在物种之间是不同的，并决定了物种之间分布模式的差异。这项研究将通过量化卵发育率随温度变化的种间和种内变化来检验这一假设，看看它是否解释了四种鱼类之间鱼群大小丰度关系的差异。本研究将为四种温带淡水鱼提供基于机械的环境生态位模型，这将为保护规划者提供有关当前分布和响应人为气候变化的分布变化的信息。该项目还将推进一个广泛适用的框架，以便为其他温带淡水鱼物种，特别是受威胁和濒危物种开发环境生态位模型。这些模型将分发给各州自然资源机构，并将纳入规划工具，为大平原的保护工作提供信息。该项目将为本科生提供实地和实验室环境的实际研究经验，并支持博士生的论文研究。

Predicting where species occur on a landscape is a fundamental aspect of ecology and an essential step in the conservation of biological diversity. Environmental niche modeling is a common tool for predicting species distributions, but limited understanding of causal relationships between the occurrence or abundance of a species and environmental variables limits the generality of these models. Improved understanding of how individual performance varies along environmental gradients is necessary to develop mechanistically-based environmental niche models. This research is motivated by the observation that the distribution of many stream fishes varies along a stream size gradient, but little is known about the mechanistic relationship between stream size and species distribution. The project will develop niche models to predict distribution of fish species in streams draining the Flint Hills of the central United States, which exhibit a strong temperature gradient from headwaters to large rivers. Given the universal importance of temperature as an environmental factor constraining metabolic, survival, and growth rates of individuals and vital rates of populations, it is predicted that temperature-dependent performance varies among species and determines among-species differences in distributional patterns. This study will test that hypothesis by quantifying inter- and intraspecific variation in egg developmental rate as a function of temperature to see if it explains differences in stream size - abundance relationships among four fish species.This study will provide mechanistically-based environmental niche models for four temperate freshwater fish species, which will inform conservation planners about current distributions and distributional changes in response to anthropogenic climate change. The project will also advance a broadly-applicable framework for developing environmental niche models for other temperate freshwater fish species, particularly threatened and endangered species. These models will be disseminated to state natural resource agencies and will be incorporated into planning tools used to inform conservation efforts in the Great Plains. This project will provide an undergraduate student with practical research experience in field and laboratory settings and support the dissertation research of a doctoral student.