Integrating spatial and temporal processes to understand the effects of multiple environmental stressors on ecosystems

人类引起的环境压力因素，如全球气候变化、非本地物种的引入以及土地利用、水质和栖息地的改变，是生态系统变化和生物多样性丧失的主要驱动因素。我的目标是了解淡水系统对环境压力的反应。很少有研究预测多种相互作用的环境压力对物种的影响，在群落水平上的研究较少。我们将开发多元统计模型，以确定多种人为环境压力因素对安大略省和威斯康星州温水、冷水和冷水鱼类群落的影响。我们将比较范围扩张和收缩的极端情况，监测暖水鱼类向北扩散，以及南部冷水鱼类的灭绝。这些模型将允许评估在不同气候变化、入侵物种和土地利用情景下环境变化如何影响淡水鱼群落。随后，我们将确定多个环境压力源如何在多个空间尺度上发挥其影响。我们将采用空间统计方法来开发模型，确定影响本地、区域、大陆和全球空间尺度上物种分布的生物和非生物决定因素。我们将应用环境变化情景来预测多种环境压力因素如何在一定的空间尺度上影响本地鱼类群落的灭绝。最后，利用北半球超过75个湖泊长达550年的冰盖记录，我们将整合短期、中期和长期尺度的时间过程，以区分自然振荡动力学和人为引起的气候变化的作用，以确定冰物候模式如何跨越空间和时间变化。因此，我们建议在全球范围内提高我们对加拿大湖泊水生生态系统对水质和生物多样性威胁的反应的理解。

Human-induced environmental stressors, such as global climate change, introduction of non-indigenous species, and alterations in land use, water quality and habitat, are among the leading drivers of ecosystem change and loss of biodiversity. My goal is to understand the response of freshwater systems to environmental stressors. Few studies predict the effects of multiple interacting environmental stressors on species, and fewer studies have been conducted at the community level. We will develop multivariate statistical models to determine the effects of multiple human-induced environmental stressors on warmwater, coolwater, and coldwater fish communities at the extents of their ranges in Ontario and Wisconsin. We will compare extremes in range expansion and contraction, monitoring the northward dispersal of warmwater fish, and the extirpation of coldwater fish in the south. These models will allow for an assessment of how environmental variability will affect freshwater fish communities under different climate change, invasive species, and land-use scenarios. Subsequently, we will determine how multiple environmental stressors exert their influence across multiple spatial scales. We will employ spatial statistical methods to develop models identifying biotic and abiotic determinants influencing species distributions at local, regional, continental, and global spatial scales. We will apply scenarios of environmental change to predict how multiple environmental stressors impact the extirpation of native fish communities at a range of spatial scales. Finally, using ice-cover records for over 75 lakes across the Northern Hemisphere spanning up to 550 years, we will integrate temporal processes at short-, medium-, and long-time scales to differentiate the role of natural oscillatory dynamics and anthropogenically induced climatic change in an effort to determine how patterns of ice phenology have changed across space and time. Therefore, we propose to improve our understanding of the response of aquatic ecosystems to threats on water quality and biodiversity in Canadian lakes within a global context.