南岭国家级自然保护区南坡乔木层物种多样性的垂直分布特征

Vertical Distribution Characteristics of Species Diversity in Canopy Layer in Southern Slope of Nanling National Nature Reserve

摘要:

为探究植物多样性随海拔梯度的变化趋势，了解群落间物种更替规律，以南岭国家自然保护区南坡的植被群落为研究对象，于2018年7月—8月以100 m为梯度沿海拔建立样地进行每木调查，分析300~1 800 m海拔梯度范围内的乔木层植被物种组成、物种多样性和物种更新速率的垂直分布特征。结果表明，随海拔的升高，乔木层物种多样性呈双峰曲线变化，群落间相异性也增大，且随着海拔差值扩大而逐渐增大，而在研究区内，物种更新速率在垂直梯度上表现出不明显的变化。不同海拔区域的群落生产策略有所不同，低海拔地区以中物种数+少个体数+高单株生物量为主，中海拔地区以多物种数+中个体数+中生物量为主，高海拔地区则以少物种数+多个体数+低单株生物量为主。提高物种多样性能为生态系统提高更多生态位和更高的抵抗力稳定性，有益于保护对环境变化敏感的珍稀濒危植物和重点保护植物。

Abstract:

To investigate the changing trend in plant diversity along the altitude gradient and understand the species replacement rules among communities, the vegetation communities on the southern slope of Nanling National Nature Reserve were selected as the research object. From July to August 2018, plots were established at 100 m intervals along the altitude for individual tree surveys. The vertical distribution characteristics of the species composition, species diversity and species renewal rate of the tree layer vegetation within the altitude range of 300-1 800 m were analyzed. The results showed that with the increase of altitude, the species diversity of the tree layer presented a double-peak curve change, and the dissimilarity among communities also increased, gradually increasing with the expansion of the altitude difference. In the study area, the species renewal rate showed no obvious change along the vertical gradient. The production strategies of communities at different altitudes were different. In the low-altitude area, it was mainly characterized by medium species number + few individuals + high individual biomass; in the medium-altitude area, it was mainly characterized by many species+ medium individuals + medium biomass; and in the high-altitude area, it was mainly characterized by few species + many individuals + low individual biomass. Increasing species diversity can provide more ecological niches and higher resistance stability for the ecosystem, which is beneficial to the protection of rare and endangered plants and key protected plants that are sensitive to environmental changes.