Identifying physical and ecological boundaries that limit where species can occur is important for predicting how those species will respond to global change. The island of Borneo encompasses a wide range of habitats that support some of the highest richness on Earth, making it an ideal location for investigating ecological mechanisms underlying broad patterns of species distribution. We tested variation in richness and range-size in relation to edaphic specialization and vegetation zone boundaries using 3060 plant species from 193 families centered around the elevational gradient of Mt Kinabalu, Borneo. Across species, average range-size increased with elevation, consistent with Rapoport's rule. However, plants associated with ultramafic soil, which is low in nutrient and water availability and often has high concentrations of heavy metals, had larger range-sizes and greater richness than expected along the elevational gradient, as compared to a null model with randomization of edaphic association. In contrast, non-ultramafic species had smaller range-sizes and lower richness than expected. These results suggest that tolerance of resource limitation may be associated with wider range-sizes, whereas species intolerant of edaphic stress may have narrower range-sizes, possibly owing to more intense competition in favorable soil types. Using elevation as a predictor of average range-sizes, we found that piece-wise models with breakpoints at vegetation zone transitions explained species distributions better than models that did not incorporate ecological boundaries. The greatest relative increases in range-size with respect to elevation occurred mid-elevation, within the montane cloud forest vegetation zone. Expansion of average range-size across an area without physical boundaries may indicate a shift in ecological strategy and importance of biotic versus abiotic stressors. Our results indicate that elevational range-size patterns are structured by ecological constraints such as species' edaphic association, which may limit the ability of species to migrate up or down mountains in response to climate change.

中文翻译：

---

土壤专业化和植被区定义了京那巴鲁山区域植物群的海拔范围大小

确定限制物种出现地点的物理和生态边界对于预测这些物种将如何应对全球变化非常重要。婆罗洲岛拥有广泛的栖息地，支持地球上一些最丰富的栖息地，使其成为研究广泛物种分布模式背后的生态机制的理想地点。我们使用以婆罗洲京那巴鲁山海拔梯度为中心的 193 个科的 3060 种植物物种，测试了与土壤专业化和植被区边界相关的丰富度和范围大小的变化。跨物种，平均范围大小随着海拔的升高而增加，这与拉波波特的规则一致。然而，与超镁铁质土壤相关的植物，其养分和水分利用率低，并且通常含有高浓度的重金属，与具有土壤关联随机化的空模型相比，沿海拔梯度具有比预期更大的范围大小和更大的丰富度。相比之下，非超镁性物种的分布范围和丰富度低于预期。这些结果表明，对资源限制的耐受性可能与更广泛的范围有关，而不能耐受土壤胁迫的物种可能具有更窄的范围，这可能是由于有利土壤类型的竞争更加激烈。使用海拔作为平均范围大小的预测因子，我们发现在植被区过渡处具有断点的分段模型比没有包含生态边界的模型更好地解释了物种分布。范围大小相对于海拔的最大相对增加发生在海拔中部，山地云雾林植被带内。在没有物理边界的区域内扩大平均范围大小可能表明生态战略的转变以及生物与非生物压力因素的重要性。我们的研究结果表明，海拔范围大小模式是由生态约束构成的，例如物种的土壤关联，这可能会限制物种响应气候变化向上或向下迁移的能力。