Xing Shuang, Hood Amelia S C, Dial Roman J, Fayle Tom M
School of Ecology Sun Yat-Sen University Guangzhou P. R. China.
Biology Centre of Czech Academy of Sciences Institute of Entomology Ceske Budejovice Czech Republic.
Ecol Evol. 2022 Jul 29;12(8):e9158. doi: 10.1002/ece3.9158. eCollection 2022 Aug.
Abiotic and biotic factors structure species assembly in ecosystems both horizontally and vertically. However, the way community composition changes along comparable horizontal and vertical distances in complex three-dimensional habitats, and the factors driving these patterns, remains poorly understood. By sampling ant assemblages at comparable vertical and horizontal spatial scales in a tropical rainforest, we tested hypotheses that predicted differences in vertical and horizontal turnover explained by different drivers in vertical and horizontal space. These drivers included environmental filtering, such as microclimate (temperature, humidity, and photosynthetic photon flux density) and microhabitat connectivity (leaf area), which are structured differently across vertical and horizontal space. We found that both ant abundance and richness decreased significantly with increasing vertical height. Although the dissimilarity between ant assemblages increased with vertical distance, indicating a clear distance-decay pattern, the dissimilarity was higher horizontally where it appeared independent of distance. The pronounced horizontal and vertical structuring of ant assemblages across short distances is likely explained by a combination of microclimate and microhabitat connectivity. Our results demonstrate the importance of considering three-dimensional spatial variation in local assemblages and reveal how highly diverse communities can be supported by complex habitats.
非生物和生物因素在水平和垂直方向上构建了生态系统中的物种组合。然而，在复杂的三维栖息地中，群落组成沿可比的水平和垂直距离变化的方式，以及驱动这些模式的因素，仍知之甚少。通过在热带雨林中以可比的垂直和水平空间尺度对蚂蚁群落进行采样，我们检验了一些假设，这些假设预测垂直和水平周转率的差异由垂直和水平空间中的不同驱动因素解释。这些驱动因素包括环境过滤，如小气候（温度、湿度和光合光子通量密度）和微生境连通性（叶面积），它们在垂直和水平空间中的结构不同。我们发现，随着垂直高度的增加，蚂蚁的丰度和丰富度均显著下降。尽管蚂蚁群落之间的差异随着垂直距离的增加而增加，表明存在明显的距离衰减模式，但在水平方向上差异更高，且似乎与距离无关。短距离内蚂蚁群落明显的水平和垂直结构可能是由小气候和微生境连通性共同作用造成的。我们的结果证明了考虑局部群落三维空间变化的重要性，并揭示了复杂栖息地如何支持高度多样化的群落。
