Biodiversity and consumer-resource interactions in fractal landscapes

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。**一些生物多样性的中性理论，包括岛屿生物地理学（IBG），忽略了这些基于性状的群落聚集解释，以及与片段干扰的相互作用。当干扰与碎片（斑块）大小正相关时，局部灭绝率可能会增加，从而导致IBG理论中的一个悖论，因为在这种情况下，生物多样性可能与碎片（岛屿）大小成反比。这种悖论有多普遍，不同的分类群对生活史特征（体型、寿命等）的反应如何，以及区域元群落和元种群或源库动态是否可以通过“拯救效应”来补偿更高的灭绝率，这些都知之甚少。**我的长期研究目标是了解与物种和生态系统的分布、动态和相互作用有关的过程，并以此为生物多样性保护提供信息。具体来说，我对空间和时间的规模和异质性如何影响种群，个体行为，植物-动物（营养）相互作用和物种组合（生物多样性）感兴趣。我建议通过检查以下两个互补的研究问题来解决这个研究目标：关键资源（野牛）的时空异质性如何影响依赖该资源的消费者（灰熊）？* 2。干扰（火灾）如何与碎片化（尺度）相互作用，从而影响生物多样性格局？**这两个问题的研究将作为一系列相关的研究项目进行，培养2名博士，3名硕士，众多本科生（~10人），1名博士后。这些项目将提供实验设计、实地研究（分类学、抽样、安全和物流等）、使用新型和新兴研究工具（即用于高分辨率遥感和3D建模的无人机）、分析（建模和统计）和假设检验等方面的培训机会。这项工作还将增加关于异质性和规模如何影响消费者-资源相互作用和生物多样性的知识。这两个主题对加拿大濒危物种和生物多样性的管理都有实际的应用，包括对当地受威胁的重要物种（灰熊）的管理，以及由于资源开发和迅速的环境变化而日益分散的西部北方森林的生物多样性保护。了解和减轻这些影响是支持可持续资源管理和加拿大环境声誉所必需的。

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.