Ding Zhifeng, Liang Jianchao, Hu Yiming, Zhou Zhixin, Sun Hongbin, Liu Lina, Liu Haijun, Hu Huijian, Si Xingfeng
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization Guangdong Institute of Applied Biological Resources Guangzhou China.
School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen China.
Ecol Evol. 2019 Mar 14;9(7):4116-4128. doi: 10.1002/ece3.5040. eCollection 2019 Apr.
Although elevational patterns of species richness have been well documented, how the drivers of richness gradients vary across ecological guilds has rarely been reported. Here, we examined the effects of spatial factors (area and mid-domain effect; MDE) and environmental factors, including metrics of climate, productivity, and plant species richness on the richness of breeding birds across different ecological guilds defined by diet and foraging strategy. We surveyed 12 elevation bands at intervals of 300 m between 1,800 and 5,400 m a.s.l using line-transect methods throughout the wet season in the central Himalaya, China. Multiple regression models and hierarchical partitioning were used to assess the relative importance of spatial and environmental factors on overall bird richness and guild richness (i.e., the richness of species within each guild). Our results showed that richness for all birds and most guilds displayed hump-shaped elevational trends, which peaked at an elevation of 3,300-3,600 m, although richness of ground-feeding birds peaked at a higher elevation band (4,200-4,500 m). The Normalized Difference Vegetation Index (NDVI)-an index of primary productivity-and habitat heterogeneity were important factors in explaining overall bird richness as well as that of insectivores and omnivores, with geometric constraints (i.e., the MDE) of secondary importance. Granivore richness was not related to primary production but rather to open habitats (granivores were negatively influenced by habitat heterogeneity), where seeds might be abundant. Our findings provide direct evidence that the richness-environment relationship is often guild-specific. Taken together, our study highlights the importance of considering how the effects of environmental and spatial factors on patterns of species richness may differ across ecological guilds, potentially leading to a deeper understanding of elevational diversity gradients and their implications for biodiversity conservation.
尽管物种丰富度的海拔格局已有充分记录，但丰富度梯度的驱动因素如何在不同生态类群间变化却鲜有报道。在此，我们研究了空间因素（面积和中域效应；MDE）和环境因素，包括气候、生产力指标以及植物物种丰富度，对不同生态类群（根据食性和觅食策略定义）繁殖鸟类丰富度的影响。我们在中国喜马拉雅山脉中部的雨季，使用样线法在海拔1800米至5400米之间每隔300米的12个海拔带进行了调查。采用多元回归模型和层次划分法来评估空间和环境因素对总体鸟类丰富度和类群丰富度（即每个类群内物种的丰富度）的相对重要性。我们的结果表明，所有鸟类和大多数类群的丰富度呈现驼峰状海拔趋势，在海拔3300 - 3600米处达到峰值，尽管地面取食鸟类的丰富度在更高海拔带（4200 - 4500米）达到峰值。归一化植被指数（NDVI）——初级生产力指标——和栖息地异质性是解释总体鸟类丰富度以及食虫和杂食性鸟类丰富度的重要因素，几何约束（即中域效应）次之。食谷鸟类丰富度与初级生产无关，而与开阔栖息地有关（食谷鸟类受到栖息地异质性的负面影响），在开阔栖息地种子可能丰富。我们的研究结果提供了直接证据，表明丰富度与环境的关系通常具有类群特异性。综上所述，我们的研究强调了考虑环境和空间因素对物种丰富度格局的影响如何在不同生态类群间存在差异的重要性，这可能有助于更深入地理解海拔多样性梯度及其对生物多样性保护的意义。
