Spatial patterns in the abundance, distribution and characteristics of organisms are a fundamental feature of all ecosystems. However, achieving a mechanistic understanding of the forces behind these population patterns is a major challenge for ecologists due to the number and diversity of variables and relationships involved. Here, we developed a spatially‐explicit agent‐based model to determine the minimum individual characteristics and environmental relationships necessary to reproduce population patterns observed in the field across habitat quality. We designed the model so each trait and mechanism could be independently included or excluded allowing us to systematically identify their impacts. The model was parameterized and outputs compared to natural population patterns using data collected on an archetypical species, the mud crab Panopeus herbstii – a species that experiences drastic habitat degradation when oyster reefs are harvested or deteriorate. Surprisingly few parameters were required to reproduce field patterns. Food availability was the primary environmental determinant of spatial patterns, as crab abundances increased almost directly proportional to this variable. The main individual level mechanisms were the ability to detect food as well as size‐ and personality‐dependent movement, since proportionally more active individuals aggregated in high quality habitat. Although habitat‐ and size‐dependent mortality influenced the magnitude of differences in population demographics across habitats, these relationships did not impact the nature of the predicted patterns. Our model demonstrates that a few simple rules can underlie complex population patterns and highlights the importance of phenotypic differences, particularly in movement, for shaping populations across heterogenous terrain. The approach used here provides a framework for identifying the roles of multiple mechanisms in structuring complex systems, and demonstrates the importance of sensory limits, movement propensity of individuals and the availability of limiting resources for producing quantitative predictions of population responses to habitat change, such as degradation or restoration efforts.

中文翻译：

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哪些机制负责不同质量生境的种群格局？一种新方法

生物体的丰度，分布和特征的空间格局是所有生态系统的基本特征。然而，由于涉及变量和关系的数量和多样性，对这些种群模式背后的作用机理进行机械理解是一个重大挑战。在这里，我们开发了一种基于空间显式代理的模型，以确定在栖息地质量范围内再现实地观察到的种群格局所必需的最小个体特征和环境关系。我们设计了模型，以便可以分别包含或排除每个特征和机制，从而使我们能够系统地确定其影响。对模型进行参数化，并使用在典型物种泥蟹上收集的数据将输出与自然种群模式进行比较人参–当牡蛎礁被捕捞或退化时，其栖息地急剧退化的物种。令人惊讶的是，几乎不需要参数来重现场模式。粮食供应是空间格局的主要环境决定因素，因为蟹的丰度几乎与该变量成正比增加。主要的个体层面机制是检测食物以及依赖大小和个性的运动的能力，因为成比例活跃的个体聚集在高质量的栖息地中。尽管依赖于栖息地和大小的死亡率影响了不同栖息地之间人口统计学差异的程度，但这些关系并未影响预测模式的性质。我们的模型表明，一些简单的规则可以构成复杂的种群模式的基础，并强调了表型差异（特别是在运动中）对于跨异质地形塑造种群的重要性。这里使用的方法提供了一个框架，用于识别多种机制在构建复杂系统中的作用，并展示了感官极限，个体的运动倾向以及有限资源的可用性的重要性，这些资源可用于对人口对栖息地变化的反应进行定量预测，例如降级或恢复工作。