Liang Jianchao, Hu Huijian, Ding Zhifeng, Lie Ganwen, Zhou Zhixin, Singh Paras Bikram, Zhang Zhixiang, Ji Shengnan
Laboratory of Systematic Evolution and Biogeography of Woody Plants School of Ecology and Nature Conservation Beijing Forestry University Beijing China.
Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and Utilization Institute of Zoology Guangdong Academy of Sciences Guangzhou China.
Ecol Evol. 2021 Jun 26;11(14):9385-9395. doi: 10.1002/ece3.7744. eCollection 2021 Jul.
A fundamental yet controversial topic in biogeography is how and why species range sizes vary along spatial gradients. To advance our understanding of these questions and to provide insights into biological conservation, we assessed elevational variations in the range sizes of vascular plants with different life forms and biogeographical affinities and explored the main drivers underlying these variations in the longest valley in China's Himalayas, the Gyirong Valley. Elevational range sizes of vascular plants were documented in 96 sampling plots along an elevational gradient ranging from 1,800 to 5,400 m above sea level. We assessed the elevational variations in range size by averaging the range sizes of all recorded species within each sampling plot. We then related the range size to climate, disturbance, and the mid-domain effect and explored the relative importance of these factors in explaining the range size variations using the Random Forest model. A total of 545 vascular plants were recorded in the sampling plots along the elevational gradient. Of these, 158, 387, 337, and 112 were woody, herbaceous, temperate, and tropical species, respectively. The range size of each group of vascular plants exhibited uniform increasing trends along the elevational gradient, which was consistent with the prediction of Rapoport's rule. Climate was the main driver of the increasing trends of vascular plant range sizes in the Gyirong Valley. The climate variability hypothesis and mean climate condition hypothesis could both explain the elevation-range size relationships. Our results reinforce the previous notion that Rapoport's rule applies to regions where the influence of climate is the most pronounced, and call for close attention to the impact of climate change to prevent species range contraction and even extinction due to global warming.
生物地理学中一个基本但存在争议的话题是物种分布范围大小如何以及为何会沿着空间梯度变化。为了增进我们对这些问题的理解，并为生物保护提供见解，我们评估了中国喜马拉雅山脉最长的山谷——吉隆沟中不同生活型和生物地理亲缘关系的维管植物分布范围大小的海拔变化，并探究了这些变化背后的主要驱动因素。在海拔从1800米到5400米的海拔梯度上的96个采样点记录了维管植物的海拔分布范围大小。我们通过平均每个采样点内所有记录物种的分布范围大小来评估分布范围大小的海拔变化。然后，我们将分布范围大小与气候、干扰和中间区域效应相关联，并使用随机森林模型探究这些因素在解释分布范围大小变化中的相对重要性。在沿海拔梯度的采样点共记录了545种维管植物。其中，分别有158种、387种、337种和112种为木本、草本、温带和热带物种。每组维管植物的分布范围大小沿海拔梯度均呈现出一致的增加趋势，这与拉波波特法则的预测相符。气候是吉隆沟维管植物分布范围大小增加趋势的主要驱动因素。气候变异性假说和平均气候条件假说都能解释海拔-分布范围大小的关系。我们的结果强化了之前的观点，即拉波波特法则适用于气候影响最为显著的地区，并呼吁密切关注气候变化的影响，以防止物种分布范围因全球变暖而收缩甚至灭绝。
