Dynamics of plant-herbivore-climate interactions in alpine and arctic communities

生态学家长期以来一直在争论各种因素如何决定捕食者(自上而下的力量)或资源(自下而上的力量)或非生物影响(例如天气和气候)将在不同的生态系统中占据主导地位的时间和地点。能够更好地预测北方和高山环境对不同尺度干扰的反应，对于制定保护生物多样性、恢复退化栖息地和管理气候变化后果的可行战略至关重要。我的研究项目专注于了解北部高山和苔原环境中植物-草食动物-气候的相互作用。该研究计划的重点研究区域位于育空山脉西南部的Kluane湖(北纬61°，西经141°)以东的红宝石山脉。这一建议进一步发展了几个纳入长期(1995年以来)计划的研究主题，包括：(1)评估高山哺乳动物对气候年际变化，特别是季节性积雪的人口和行为反应；(2)确定资源可获得性和捕食风险对食草动物种群(鼠兔、旱獭、地松鼠)行为和人口学的影响，作为检验营养开发模式预测的模式系统；(3)测量高山植被对不同水平的自然和实验草食以及气候、生理、人口和群落层面的年际变化的反应；(4)建立区域模型，以评估景观层面的过程(如雪、树线和灌木线动态等)对生物多样性的影响；以及5)通过长期监测、教育、宣传和整合科学知识和社区知识，确保北部冻土带和高山环境的可持续性的机制。

Ecologists have long debated how various factors determine when and where predators (top-down forces) or resources (bottom-up forces) or abiotic influences (e.g. weather and climate) will be predominant in different ecosystems. Being able to better predict the responses of northern and alpine environments to disturbance at different scales is essential for developing viable strategies for conserving biodiversity, restoring degraded habitats, and managing the consequences of climate change. My research program is focused on understanding plant-herbivore-climate interactions in northern alpine and tundra environments. The focal study areas for this research program are located in the mountains of the southwest Yukon, in the Ruby Ranges east of Kluane Lake (61° N, 141° W). This proposal further develops several research themes that are integrated into a long-term (since 1995) program, including (1) Evaluation of the demographic and behavioural responses of alpine mammals to inter-annual variation in climate, especially seasonal snow cover; (2) Determination of the effects of resource availability and predation risk on the behaviour and demography of herbivore populations (pikas, marmots, ground squirrels), as model system for testing the predictions of the trophic exploitation models; (3) Measurement of the responses of alpine vegetation to different levels of natural and experimental herbivory and interannual variation in climate, at physiological, demographic and community levels; (4) Construction of regional models to assess the influence of landscape-level processes (e.g. snow, treeline and shrubline dynamics, etc) on biodiversity; and 5) Mechanisms for ensuring sustainability of northern tundra and alpine environments, through long-term monitoring, education, outreach, and integration of scientific and community-based knowledge.