Regulation of ecosystems and biodiversity loss

生态系统监管和生物多样性丧失

• 批准号: RGPIN-2014-05657
• 负责人: Sinclair, Anthony
• 金额: $ 3.64万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632151
• 关键词: Regulation; ecosystems; biodiversity; loss

The primary purpose is to conduct a long term research program on biodiversity and ecosystem dynamics in the Serengeti ecosystem, East Africa. We use Protected Areas as Ecological Baselines to compare with human-dominated ecosystems outside. The Serengeti provides a unique opportunity to understand (1) how a natural ecosystem works, (2) what role biodiversity plays in this system, and (3) what human influences are threatening this biodiversity. The Main Questions are: 1. What are the rules for the sustainability and resilience of ecosystems? 2. How do disturbances cause changes in state or destabilize ecosystems? 3. What are the consequences when components of biodiversity are lost from a system? The hypothesis that I test is that moderate (natural) disturbances are buffered by complex stabilizing negative feedbacks within the diverse community, but large disturbances (agriculture) result in shifts in community composition and form multiple states. I use 3 approaches: (1) Understanding the dynamics using large scale disturbance; (2) Analysis of the multispecies interactions by studies of individual movements; (3) Understanding the consequences of loss of biodiversity by experimental removal of some parts of the biota.1. Dynamics of the ecosystem using large scale perturbations. There are 6 perturbations that affect this system: 2 abiotic (fire, drought), 2 biotic (grazing by migrants, disease epizootics), 2 human induced (agriculture, hunting). (i) What are the direct and indirect effects of these impacts? (ii) Which species are affected, does composition change, and do some go locally extinct? (iii) What is the time scale of change and return, and is there more than one state? A team of trained field technicians obtains data from systematic sampling on all the major biotic components of the system – soil organisms, plants, mammals, birds, insects, while other data are supplied from colleagues that work with us on large carnivores, and diseases.2. Multispecies movement models. This project is concerned with the rules for the stability of communities. (i) what are the stability properties for living in groups? (ii) What are the rules for movement and how do they affect stability? (iii) How do herbivores trade-off the needs for food with reduction of risk of predation? We hypothesize that predator (lions) behavior is determined by prey herd size, encounter rates and population density for each prey species. We have four objectives. i. We develop mechanistic movement models for 6 herbivore species eaten by Serengeti carnivores. ii. We use GPS data to test carnivore movement models. iii. We use these models to see how carnivores can link to the movements of migrant prey. iv. We examine when resource-searching by herbivores switches to risk-aversion, and how this is modified by food quality and abundance.3. The biodiversity knockout experiment (BioKO). This program is designed to understand the role that functional groups of our biota play in whole versus communities that have lost species. The essence of the experiment is to knock out different plant functional groups then compare the stability of this reduced system with systems that have their full biota. Significance: This system provides an example for understanding the mechanisms of change. The information will allow managers to assess stability of the ecosystem for conservation, the need to maintain habitat heterogeneity, and whether management interventions are needed to modify undesirable change from human modification (agriculture, hunting) or Climate Change.

主要目的是对东非塞伦盖蒂生态系统的生物多样性和生态系统动力学进行长期研究计划。我们以保护区为生态基线，与外部以人类为主的生态系统进行比较。塞伦盖蒂提供了一个独特的机会来了解(1)自然生态系统是如何运作的，(2)生物多样性在这个系统中扮演着什么角色，以及(3)人类的影响正在威胁着这种生物多样性。主要问题是：1.生态系统的可持续性和恢复力的规则是什么？2.干扰如何引起状态的变化或破坏生态系统的稳定？3.当生物多样性的组成部分从系统中消失时，会产生什么后果？我测试的假设是，中等(自然)干扰通过多样化社区内复杂的稳定负反馈来缓冲，但大型干扰(农业)会导致社区组成的变化并形成多个状态。我使用了三种方法：(1)利用大范围干扰来理解动态；(2)通过对个体运动的研究来分析多物种的相互作用；(3)通过实验移除生物的某些部分来理解生物多样性丧失的后果。使用大尺度扰动的生态系统动力学。影响这一系统的扰动有6种：2种非生物干扰(火灾、干旱)、2种生物干扰(候鸟放牧、疾病家畜传播)、2种人为干扰(农业、狩猎)。(I)这些影响的直接和间接影响是什么？(Ii)哪些物种受到影响，成分是否发生变化，以及一些物种是否局部灭绝？(3)变化和回归的时间尺度是什么，是否有一个以上的状态？一组训练有素的现场技术人员通过对系统中所有主要生物成分--土壤生物、植物、哺乳动物、鸟类、昆虫--的系统采样获得数据，而其他数据则由与我们合作研究大型食肉动物和疾病的同事提供。多物种移动模型。该项目涉及社区稳定的规则。(I)群居的稳定性特征是什么？(2)行动的规则是什么，它们如何影响稳定？(3)食草动物如何在减少捕食风险的同时权衡对食物的需求？我们假设捕食者(狮子)的行为是由每个猎物物种的猎物群体大小、相遇几率和种群密度决定的。我们有四个目标。我们建立了6种被塞伦盖蒂食肉动物捕食的食草动物的机械运动模型。二、我们使用GPS数据来检验食肉动物的运动模型。三、我们使用这些模型来研究食肉动物如何与迁徙猎物的运动联系起来。四、我们研究了食草动物的资源搜索何时转变为风险厌恶，以及这是如何被食物质量和丰度所修正的。生物多样性淘汰实验(Bioko)。这项计划旨在了解生物群的功能群在整个生物群中所起的作用，以及与已经丧失物种的群落的作用。实验的实质是剔除不同的植物功能群，然后将这个简化系统的稳定性与具有完整生物群的系统进行比较。意义：这个系统为理解变化的机制提供了一个例子。这些信息将使管理者能够评估保护生态系统的稳定性，维持栖息地异质性的必要性，以及是否需要管理干预来改变人类改造(农业、狩猎)或气候变化带来的不良变化。