Biodiversity and consumer-resource interactions in fractal landscapes

生态学中的一个中心问题是，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。回答这个问题在一定程度上需要知道物种对其资源(食物)进行抽样的规模，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)或群落中物种的集合(生物多样性)。资源斑块分布的异质性可以用分形几何来描述，并随消费者的身体大小以及觅食行为和斑块占有率的变化而变化，因为生物体以与其觅食效率相关的感知颗粒对其环境进行采样。生物体感知和使用资源的规模也有助于解释物种在群落中共存的模式，因为它们可能不会直接竞争相同的资源。 许多关于生物多样性的中性理论，包括岛屿生物地理学(IBG)，忽视了对群落聚集的这些基于特征的解释，以及与碎片干扰的相互作用。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，因为在这些条件下，生物多样性可能与碎片(岛屿)大小成反比。关于这一悖论有多普遍，不同的类群如何与生活史特征(体型、寿命等)做出反应，人们知之甚少。无论是区域性的集合群落和集合种群，还是源-汇动态，都可以通过“拯救效应”来补偿更高的物种灭绝速度。 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，并利用这一过程为生物多样性保护提供信息。具体地说，我感兴趣的是空间和时间上的规模和异质性如何影响种群、个体行为、动植物(营养)相互作用和物种组合(生物多样性)。我建议通过考察以下两个相辅相成的研究问题来解决这一研究目标： 1.关键资源(野莓)的空间和时间异质性如何影响依赖该资源(灰熊)的消费者？ 2.干扰(火灾)如何与碎片化(规模)相互作用以影响生物多样性格局？ 对这两个问题的研究将作为一系列相关研究项目进行，以培养2名博士、3名硕士、众多本科生(~10名)和1名博士后。这些项目将在实验设计、实地研究(分类学、抽样、安全和后勤等)、使用新的新兴研究工具(如用于高分辨率遥感和3D建模的无人机)、分析(建模和统计)和假设检验方面提供培训机会。这项工作还将增加关于异质性和规模如何影响消费者-资源互动和生物多样性的知识。这两个主题在加拿大的濒危物种和生物多样性管理方面都有实际应用，包括管理当地受威胁的高调物种(灰熊)和西部北方森林的生物多样性保护，该森林正因资源开发而日益分散，并受到快速环境变化的威胁。需要了解和减轻这些影响，以支持可持续资源管理和加拿大的环境声誉。

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.