Spatial variation in the density of ectotherms

变温动物密度的空间变化

• 批准号: RGPIN-2018-04234
• 负责人: BlouinDemers, Gabriel
• 金额: $ 3.42万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689577
• 关键词: Spatial; variation; density; ectotherms

Within species, abundance (population density) varies markedly in space and in time. Accordingly, explaining spatial and temporal patterns in the abundance of species is one of the major goals of ecology. The abundant center hypothesis posits that species should be most abundant near the center of their geographic ranges, but the empirical data do not support it. Thus, there is a clear need for alternative hypotheses to predict better the spatial patterns in the abundance of animals.******Predicting spatial patterns in the abundance of animals has important theoretical and applied implications. On the theoretical side, a better prediction of spatial patterns in abundance may help determine what drives broad spatial patterns in biodiversity. On the applied side, a better ability to predict spatial patterns will help define critical habitats for species at risk.******Abundance at broad spatial scales is largely dictated by climate. Within the geographical range of species, however, habitat selection can strongly influence the distribution and abundance of individuals. The spatial heterogeneity of resource distribution provides an opportunity for organisms to maximize their fitness by choosing the highest quality habitat available. The suitability of a habitat is determined by the mean success rate of individuals that occupy the habitat, and depends on factors such as food abundance, shelter availability, and density of competitors.******Much of the habitat selection theory assumes that animals are limited by their ability to harvest limited resources. But what happens if animals are limited by their ability to process resources? Most animals are ectotherms, and in ectotherms the total amount of energy available may be more strongly influenced by thermal constraints on resource assimilation than by resource acquisition. My working hypothesis is that the primary driver of abundance in ectotherms is their ability to process resources, not their ability to acquire resources.******The long-term objective of my research program is to determine what dictates spatial patterns of abundance in ectotherms. To meet this objective, I document patterns of abundance in space and I test hypotheses about mechanisms that could generate these spatial patterns. My objective over the next grant cycle is to determine whether it is the ability to acquire, or the ability to process, resources that best predicts abundance of ectotherms. I will address this objective at three spatial scales: at the scale of the geographical range (variation in abundance across the range), at the scale of the landscape (variation in abundance across habitat gradients), and at the scale of the individual home ranges (variation in fitness between home ranges varying in quality).

在物种中，丰度（人口密度）在空间和及时差异很大。因此，解释丰富物种中的空间和时间模式是生态学的主要目标之一。大量的中心假设认为，物种在其地理范围的中心附近应该最丰富，但是经验数据不支持它。因此，显然需要替代假设，以更好地预测动物丰度的空间模式。******预测动物丰度的空间模式具有重要的理论和应用含义。从理论方面来说，在丰度中更好地预测空间模式可能有助于确定什么推动了生物多样性中广泛的空间模式。在应用方面，预测空间模式的更好能力将有助于定义有风险的物种的关键栖息地。******在广泛的空间尺度上的丰富度很大程度上取决于气候。但是，在物种的地理范围内，栖息地的选择可以强烈影响个体的分布和丰度。资源分配的空间异质性为生物提供了一个机会，可以通过选择可用的最高质量栖息地来最大化其健身。栖息地的适用性取决于占据栖息地的个体的平均成功率，并取决于诸如粮食丰度，庇护所的可用性和竞争者密度等因素。但是，如果动物受到处理资源的能力的限制会发生什么？大多数动物是屈光度，在调热中，可用的总能量可能比资源同化的热约束更强烈，而不是资源获取。我的工作假设是，次热中丰度的主要驱动力是它们处理资源的能力，而不是他们获得资源的能力。为了满足这一目标，我记录了空间中丰富的模式，并测试了有关可能产生这些空间模式的机制的假设。我对下一个赠款周期的目标是确定它是获得能力的能力，还是能够最能预测丰富量热的资源的能力。我将在三个空间尺度上解决这一目标：在地理范围的尺度上（整个范围的丰度变化），景观的尺度（跨栖息地梯度的丰度变化）和单个家居范围的规模（在质量质量的质量变化的家庭范围变化）。