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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=665268
• 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态进行长期研究。 我们使用保护区作为生态基线，与外部人类主导的生态系统进行比较。 塞伦盖蒂平原提供了一个独特的机会来了解（1）自然生态系统如何运作，（2）生物多样性在这个系统中扮演什么角色，以及（3）人类的影响正在威胁着这种生物多样性。 主要问题有：1.生态系统的可持续性和复原力的规则是什么？2.干扰是如何引起状态变化或破坏生态系统稳定的？ 3.当生物多样性的组成部分从一个系统中消失时，会产生什么后果？我测试的假设是，中度（自然）干扰的缓冲复杂的稳定负反馈在不同的社区，但大的干扰（农业）导致社区组成的变化，并形成多个国家。我使用3种方法：（1）利用大尺度扰动来理解动态;（2）通过研究个体运动来分析多物种的相互作用;（3）通过实验性地移除某些生物群来理解生物多样性丧失的后果。1.利用大尺度扰动的生态系统动力学。影响该系统的扰动有6种：2种非生物扰动（火灾、干旱），2种生物扰动（候鸟放牧、动物流行病），2种人为扰动（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，是否有一些物种在当地灭绝？(iii)变化和回归的时间尺度是什么，是否存在不止一种状态？一组训练有素的现场技术人员从系统的所有主要生物组成部分（土壤生物、植物、哺乳动物、鸟类、昆虫）的系统采样中获得数据，而其他数据则来自与我们合作研究大型食肉动物和疾病的同事。2.多物种运动模型。该项目涉及社区稳定的规则。(i)群居的稳定性是什么(ii)运动的规则是什么？它们如何影响稳定性？(iii)食草动物如何在食物需求与减少捕食风险之间进行权衡？我们假设，捕食者（狮子）的行为是由猎物群体的大小，遇到率和人口密度为每个猎物物种。我们有四个目标。I.我们开发了6种食草动物被塞伦盖蒂食肉动物吃掉的机械运动模型。二.我们使用GPS数据来测试食肉动物的运动模型。三.我们使用这些模型来观察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寻何时转向风险规避，以及食物质量和丰富度如何改变这一点。3.生物多样性敲除实验（BioKO）。该计划旨在了解我们生物群的功能群在整个社区与失去物种的社区中所扮演的角色。实验的本质是敲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机制提供了一个例子。这些信息将使管理人员能够评估生态系统的稳定性，以保护，需要保持栖息地的异质性，以及是否需要管理干预措施来修改人类改造（农业，狩猎）或气候变化的不良变化。