Ant diversity in Neotropical savannas: hierarchical processes acting at multiple spatial scales

1. Understanding what creates and maintains macroscale biodiversity gradients is a central focus of ecological and evolutionary research. Spatial patterns in diversity are driven by a hierarchy of factors operating at multiple scales. Historical and climatic factors drive large-scale patterns of diversity by affecting the size of regional species pools, while habitat heterogeneity or microhabitat characteristics further influence species coexistence at small scales.
2. We tested the degree to which the species-energy, historical factors, habitat heterogeneity and local environment hypotheses explain observed patterns of ant diversity across hierarchical spatial scales.
3. We sampled ground-dwelling ants at 29 sites within a Neotropical savanna region, the Brazilian Cerrado. We measured species density – an abundance-dependent diversity metric – and rarefied species richness – an abundance-independent metric – at spatial scales with varying grain sizes. For each hypothesis, two correla...

1. 阐明驱动并维持宏观尺度生物多样性梯度的核心机制，是生态学与进化生物学研究的关键议题。生物多样性的空间格局由多尺度下的层级式调控因子共同驱动。历史与气候因子通过调控区域物种库（regional species pools）的规模，塑造大尺度的生物多样性格局；而生境异质性或微生境特征则进一步在小尺度上影响物种种群的共存。
2. 本研究旨在检验物种能量假说、历史因子假说、生境异质性假说与局域环境假说，在层级式空间尺度下对观测到的蚂蚁多样性格局的解释程度。
3. 本研究在新热带稀树草原区域——巴西塞拉多（Brazilian Cerrado）的29个样点中，对地表栖息蚂蚁开展了采样工作。我们在空间粒度各异的多个尺度下，测定了物种密度（species density，一种依赖丰度的多样性指标）与稀疏化物种丰富度（rarefied species richness，一种不依赖丰度的多样性指标）。针对每一类假说，我们开展了两项相关性分析（原文后续内容截断）。