Interacting effects of climate change and grazing on temperate grasslands

气候变化和放牧对温带草原的相互作用影响

• 批准号: 312155-2011
• 负责人: Fraser, Lauchlan
• 金额: $ 1.89万
• 依托单位: Thompson Rivers University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571701
• 关键词: Interacting; effects; climate; change; grazing

My research program examines the processes that organize plant communities and the functional consequences of different emergent assemblages on ecosystem properties. The ecosystem I study, temperate grassland, is among the most threatened ecosystems globally. Less than one percent of British Columbia's land base is grassland, and the remaining grasslands are threatened by over-grazing, non-native invasives, urban development, and global climate change; therefore my results have immediate practical value in restoration and conservation efforts. To understand the processes that control plant communities it is necessary to take an integrated, multi-scaled approach. My research will be conducted across different grassland types and over a wide range of spatial scales: from single-plant pot experiments in a controlled greenhouse setting, to multi-species microcosms, to controlled manipulations in natural grasslands, to landscape descriptive monitoring. The main goal of my research is to understand the mechanics of community and ecosystem functions in temperate grasslands to provide tools to enable their restoration and conservation. I propose to study stress (through climate change) and disturbance (grazing) and how these factors affect species composition, diversity and trophic interactions. The major stress in temperate grasslands is drought. Global climate change scenarios suggest that temperature will increase and that precipitation patterns will be altered, with a reduction in rainfall during the hottest months in the summer. The research I propose is unique. I plan to alter micro-climatic conditions in grasslands along a natural environmental productivity gradient by manipulating temperature (through open-top-chambers) and water supply (through rain shelters and water additions). In combination with these abiotic factors, an interacting effect of grazing and litter (dead plant material) manipulations will be applied. The grasslands I study are located in the Thompson Plateau in Southern British Columbia. My objectives are: 1. Test how productivity affects the stability of grasslands to perturbations of both stress (drought) and disturbance (grazing). 2 Determine the relative importance of top-down and bottom-up controls in grasslands along a natural productivity gradient, and the role of detritivores. 3 Use species traits to make predictions regarding species distribution, abundance and community composition and then relate that information to objectives 1 and 2. The methods for this proposal are divided into three separate experiments. The first is a factorial field experiment testing the effects of climate change (temperature and precipitation) in conjunction with grazing to test the resistance of the grasslands to disturbance along a productivity gradient. The second field experiment will assess the role of top-down and bottom-up processes on plant and animal community structure. Finally, plant species trait screening in the greenhouse will examine correlations between plant traits and observed patterns in the field. The projects I propose consist of a combination of small- and long-term hypothesis-driven questions. My publications and grant success demonstrate that I can plan, execute, and deliver hypothesis-driven research.

我的研究项目探讨了组织植物群落的过程，以及不同的紧急集合对生态系统特性的功能后果。我研究的生态系统，温带草原，是全球最受威胁的生态系统之一。 不到百分之一的不列颠哥伦比亚省的土地基础是草原，其余的草原受到过度放牧，非本地入侵，城市发展和全球气候变化的威胁，因此我的研究结果在恢复和保护工作中具有直接的实用价值。 为了了解控制植物群落的过程，有必要采取一种综合的、多尺度的方法。我的研究将在不同的草地类型和广泛的空间尺度上进行：从受控温室环境中的单植物盆栽实验，到多物种微观世界，到天然草地的受控操作，再到景观描述性监测。 我研究的主要目标是了解温带草原的群落和生态系统功能的机制，以提供工具，使其恢复和保护。我建议研究压力（通过气候变化）和干扰（放牧），以及这些因素如何影响物种组成，多样性和营养相互作用。 温带草原的主要压力是干旱。 全球气候变化情景表明，气温将上升，降水模式将改变，夏季最热月份的降雨量将减少。 我提出的研究是独一无二的。 我计划通过控制温度（通过开顶室）和供水（通过避雨棚和水补充），沿着沿着自然环境生产力梯度改变草原的微气候条件。 结合这些非生物因素，放牧和凋落物（死植物材料）操作的相互作用的影响将被应用。 我研究的草原位于不列颠哥伦比亚省南部的汤普森高原。 我的目标是： 1. 测试生产力如何影响草原对压力（干旱）和干扰（放牧）的稳定性。 2 确定草原沿着自然生产力梯度自上而下和自下而上控制的相对重要性，以及食草动物的作用。 3 利用物种特征对物种分布、丰度和群落组成进行预测，然后将这些信息与目标1和2联系起来。 该提议的方法分为三个单独的实验。 第一个是一个析因的实地实验，测试气候变化（温度和降水）的影响，结合放牧，以测试的草地干扰的抵抗力沿着生产力梯度。 第二个实地试验将评估自上而下和自下而上的进程对动植物群落结构的作用。 最后，温室中的植物物种性状筛选将检查植物性状与田间观察到的模式之间的相关性。 我提出的项目由小型和长期假设驱动问题的组合组成。我的出版物和资助的成功表明，我可以计划，执行和提供假设驱动的研究。