降水格局改变背景下基于功能性状的生物多样性变化

Biodiversity Changes Based on Functional Traits Under Context of Changing Precipitation Patterns

摘要:

全球的降水格局正发生改变，更加科学地衡量生物多样性具有紧迫性。功能多样性是生物多样性的重要组成，结合功能性状可更好地衡量植物群落对气候变化的响应。为探究气候变化背景下生物多样性的变化趋势，该研究基于鼎湖山自然保护区内不同演替进程的20 hm²样地和3个卫星样地，通过使用群落加权平均性状值、标准化的种间平均性状距离和标准化的最近种间平均性状距离量化群落功能组成和功能性状多样性的变化，研究了降水格局变化下常绿阔叶林生物多样性的变化趋势。结果表明, 降水格局的改变并未改变各个类型群落的物种多样性(α多样性)格局和物种多样性随着演替进程变化的趋势。针叶林和针阔混交林样地更多地受到演替进程的影响，功能组成向水力效率上升、安全性下降发展；阔叶成熟林和阔叶老龄林可能更多地受到降水格局变化的影响，功能组成表现向水力效率下降、安全性上升发展。针叶林和阔叶成熟林群落的功能空间表现为功能发散；针阔林和阔叶老龄林群落的功能空间表现为功能聚集，降水格局的变化可能在其中贡献了一定作用。这说明特定类型群落的生物多样性在功能组成和功能空间表现方面受到了降水格局改变的影响。

Abstract:

Global precipitation patterns are changing and there is an urgency to measure biodiversity more scientifically. Functional diversity is an important component of biodiversity, and combining functional traits can better measure the response of plant communities to climate change. In order to explore the change trend of biodiversity in the context of climate change and provide scientific support for biodiversity protection, the changes of biodiversity in the subtropical evergreen broad-leaved forest under the change of precipitation pattern were analyzed from the perspective of species diversity and functional diversity, by using community weighted mean, net relatedness index and nearest taxon index, based on the 20 hm² plot and three satellite 1 hm² plots in the succession sequence of “coniferous forest→broad-leaved mixed forest→mature broad-leaved forest→over-mature broad-leaved forest” in Dinghushan Nature Reserve. The results showed that the change of precipitation pattern did not change the pattern of species diversity (α diversity) and the change trend of species diversity with succession. The species diversity of coniferous forest and broad-leaved mixed forest increased with time, while the species diversity of mature broad-leaved forest and over-mature broad-leaved forest decreased with time. The changes of precipitation pattern had different effects on the functional composition of different communities. The coniferous forest and broad-leaved mixed forest were more affected by succession process, and their functional components showed hydraulic efficiency increased and safety decreased. The mature broad-leaved forest and over-mature broad-leaved forest were more affected by the change of precipitation pattern, and their functional components showed decrease of hydraulic efficiency and increase of safety. In terms of community functional diversity, the functional space of coniferous forest and mature broad-leaved forest showed functional divergence. The functional space of the broad-leaved mix forest and over-mature broad-leaved forest was functional converge. Changes in precipitation patterns may have played a role in these results. Therefore, it was suggested that the functional composition and functional space of biodiversity in specific community types were affected by changes in precipitation pattern.