Biodiversity and consumer-resource interactions in fractal landscapes

分形景观中的生物多样性和消费者资源相互作用

• 批准号: RGPIN-2014-04842
• 负责人: Nielsen, Scott
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 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=588051
• 关键词: Biodiversity; consumer; resource; interactions; fractal

A central question in ecology is how scale and environmental heterogeneity affect populations, trophic interactions and biodiversity. Answering this question partly requires knowing the scale at which species sample their resources (food) and how this affects the behaviour of consumers (minimum patch size requirements or giving up density) or the assemblage of species in a community (biodiversity). Heterogeneity in the distribution of resource patches can be described by fractal geometry and scales with body size of consumers as well as foraging behaviour and patch occupancy since organisms sample their environment at a perceptual grain that relates to their foraging efficiency. Scales at which organisms perceive and use a resource also helps explain patterns of coexistence of species in a community since they may not directly compete for the same resource. A number of neutral theories of biodiversity, including island biogeography (IBG), ignore these trait-based explanations of community assembly, as well as interactions with disturbance in fragments. When disturbances are positively related to fragment (patch) size, local extinction rates can increase resulting in a paradox in IBG theory since biodiversity under these conditions may be inversely related to fragment (island) size. Little is known about how common this paradox is, how different taxa respond relative to life history traits (body size, longevity, etc.) and whether regional metacommunity and metapopulation or source-sink dynamics can compensate for higher extinction rates via a ‘rescue effect’. My long-term research objective is to understand processes relating to the distribution, dynamics and interactions of species and ecosystems and to use this to inform biodiversity conservation. Specifically, I am interested in how scale and heterogeneity in space and time affect populations, behaviours of individuals, plant-animal (trophic) interactions and species assemblages (biodiversity). I propose to address this research objective by examining the following two complimentary research questions: 1. How does the spatial and temporal heterogeneity in a key resource (buffaloberry) affect a consumer dependent on that resource (grizzly bears)? 2. How do disturbances (fires) interact with fragmentation (scale) to affect biodiversity patterns? Research on these two questions will be carried out as a series of related research projects resulting in the training of 2 PhD, 3 MSc, numerous undergraduate students (~10), and 1 post-doctoral fellow. These projects will provide training opportunities in experimental design, field research (taxonomy, sampling, safety and logistics, etc.), use of novel and emerging research tools (i.e. Unmanned Aerial Vehicles [UAVs] for high resolution remote sensing and 3D modeling), analysis (modeling and statistics) and hypothesis testing. This work will also add knowledge about how heterogeneity and scale affects consumer-resource interactions and biodiversity. Both themes have real-world applications to the management of threatened species and biodiversity in Canada, including management of a locally threatened high profile species (grizzly bears) and biodiversity conservation in the western boreal forest which is being increasingly fragmented by resource development and threatened by rapid environmental change. Understanding and mitigating these effects are needed to support sustainable resource management and Canada’s environmental reputation.

生态学的一个核心问题是规模和环境异质性如何影响种群、营养相互作用和生物多样性。要回答这个问题，部分需要知道物种采集资源（食物）的规模，以及这如何影响消费者的行为（最小斑块大小要求或放弃密度）或群落中物种的聚集（生物多样性）。资源斑块分布的异质性可以用分形几何和消费者体型的尺度来描述，也可以用觅食行为和斑块占用来描述，因为生物在与其觅食效率相关的感知颗粒中对环境进行采样。生物感知和使用资源的尺度也有助于解释群落中物种共存的模式，因为它们可能不会直接竞争同一资源。