Collaborative Research: Integration of Physiological, Life-history, and Macro-ecological Approaches for Understanding Thermal Limitation in Aquatic Insects: Implications for Freshw

淡水生态系统支撑着地球上不成比例的生物多样性，是受人类活动和全球气候变化威胁最大的生态系统之一。在动物生物多样性和生态过程方面，昆虫在淡水生态系统中占据主导地位。温度控制昆虫的生长、发育时间、生存和繁殖，影响不同淡水生态系统中个体物种的分布和特定物种的集合。因此，全球变化和其他人为活动对淡水生态系统的许多影响可能通过它们对水生昆虫的热效应来表现。个别淡水昆虫分类群的温度极限以及决定这些极限的潜在生理机制仍然知之甚少。这项研究具有实际意义，因为资源机构利用水生昆虫和其他无脊椎动物来推断生态健康和水质。然而，这些数据往往很难解释，因为我们对物种如何以及为什么对高温做出不同的反应缺乏了解。这个合作项目将研究人员与广泛的专业知识联系在一起，以了解温度如何影响生物生理、生活史结果，并最终影响整个景观中的物种分布。该研究小组将在实验中操纵温度制度，以量化温度对各种蚂蚁(叶蝉目)物种的生活史结果(生存、生长速度、发育时间、大小和繁殖力)的影响。实验室实验将确定影响生活史结果的特定生理过程(呼吸作用、能量分配、代谢产物的产生和基因表达)如何对不同的温度做出反应。这些实验室研究将用于改进用于淡水生物多样性评估和监测的生态位模型(环境温度与物种在时间和空间上的分布之间的经验衍生关系)。特别是，这些研究将澄清环境温度的哪些描述因素(例如，年平均温度、平均夏季温度、地热变化幅度等)。对物种的表现最为重要。最终，这些研究旨在对热生理、生活史变异和物种分布之间的联系提供强有力的理解。强有力的外展工作将使这种理解对大型生态监测界有用。

Freshwater ecosystems support a disproportionate percentage of Earth's biodiversity and are among the most threatened by human activities and global climate change. Insects dominate fresh-water ecosystems in terms of animal biodiversity and ecological processes. Temperature controls insect growth, developmental timing, survival, and reproduction, which influence both the distributions of individual species and the specific set of species that occur in different freshwater ecosystems. Thus, many effects of global change and other anthropogenic activities on freshwater ecosystems will likely be manifested through their thermal effects on aquatic insects. The thermal limits of individual freshwater insect taxa and the underlying physiological mechanisms that determine those limits still remain poorly understood. This research has practical importance because resource agencies use aquatic insects and other invertebrates to make inferences about ecological health and water quality. However, these data are often difficult to interpret, because we have a poor understanding of how and why species are differentially responsive to elevated temperatures. This collaborative project links researchers with a broad range of expertise to understand how temperature affects organismal physiology, life-history outcomes, and ultimately the distribution of species across entire landscapes. The research team will experimentally manipulate thermal regimes to quantify the effects of temperature on life-history outcomes (survival, growth rates, development times, size and fecundity) of a diversity of mayfly (Ephemeroptera) species. Laboratory experiments will identify how the specific physiological processes that affect life-history outcomes (respiration, energy allocation, the production of metabolites, and gene expression) respond to different temperatures. These laboratory studies will be used to refine ecological niche models (empirically derived relationships between environmental temperatures and species distributions in time and space) that are used in freshwater biodiversity assessment and monitoring. In particular, these studies will clarify which descriptors of environmental temperatures (e.g. mean annual temperature, mean summer temperature, the magnitude of diel thermal change, etc.) are most important to species performance. Ultimately, these studies are intended to provide a robust understanding of the linkages between thermal physiology, life-history variation, and species distributions. Robust outreach efforts will make this understanding useful to the large ecological monitoring community.