Biotic drivers of ecosystem nutrient cycling

人类活动，如收获、城市化和农业，导致许多顶级食肉动物和食草动物的减少或灭绝。例如，纽芬兰和拉布拉多海岸附近的大西洋鳕鱼和鲑鱼数量大幅下降。人类还引进了许多食肉动物和食草动物用于娱乐或资源管理。例如，在20世纪初，驼鹿被引入纽芬兰，今天驼鹿狩猎是该省的主要产业。食肉动物和食草动物可以影响生态系统的养分循环；一种重要的支持生命的生态服务，是食品生产和水净化的基础。然而，食肉动物和食草动物的灭绝或引入对生态系统养分循环的影响尚不清楚。我的研究计划的长期目标是研究食肉动物和食草动物在生态系统养分循环中的作用。在接下来的五年里，我有三个目标来解开将食肉动物和食草动物与生态系统养分循环联系起来的不同机制；1)通过经验数据综合评估目前的知识状况；2)推导生态系统模型来预测捕食者和食草动物的灭绝和引入对生态系统营养收支的影响；3)测试纽芬兰北部地区水生和陆地生态系统中捕食者和食草动物之间关系和营养循环的理论预测。

Human activities such as harvesting, urbanization, and agriculture have led to the decline or extinction of many top predators and herbivores. For example, there has been a significant decline in Atlantic cod and salmon stocks off the coast of Newfoundland and Labrador. Humans have also introduced a number of predators and herbivores for recreation or resource management. For example, moose were introduced to Newfoundland in the early 1900s and today moose hunting is a major industry in the province. Predators and herbivores can influence ecosystem nutrient cycling; a critical life supporting ecological service which is fundamental for food production and water purification. However, the implications of the extinction or introduction of predators and herbivores on ecosystem nutrient cycling are not well understood. The long-term goal of my research program is to investigate the role of predators and herbivores in ecosystem nutrient cycling. Over the next five years I have three objectives to disentangle the different mechanisms linking predators and herbivores to ecosystem nutrient cycling; I) assess the current state of knowledge through an empirical data synthesis, II) derive ecosystem models to predict the effect of predator and herbivore extinctions and introductions on ecosystem nutrient budgets, and III) test theoretical predictions for the relationship between predators and herbivores and nutrient cycling in aquatic and terrestrial ecosystems in the boreal region of Newfoundland.