中国东部海岛植物功能性状及其影响因子

研究海岛植物功能性状及其影响因子,有助于理解植物在海岛环境中的适应策略。以中国东部近海7个海岛典型植物群落为研究对象,测定群落内每种植物的6个功能性状(胸径、株高、平均单叶面积、比叶面积、小枝密度和小枝含水率),比较植物功能性状在不同气候带间的差异,探讨功能性状对气候因子(年均温、年降水和年平均风速)和土壤因子(土壤含水率、土壤总碳、土壤总氮和土壤总磷)的响应关系,并分析影响这些性状的主要驱动因子。研究结果表明:(1)所测功能性状中除比叶面积外,其他性状在不同气候带间差异显著,但常绿和落叶植物的功能性状在不同气候带间的差异不同,表明不同生活型植物对环境的响应程度和适应能力不同。(2)海岛植物功能性状对气候和土壤因子均有不同程度的响应,气候因子是影响中国东部海岛植物功能性状的重要因子,其中水热条件(年均温和年降水)是主导因子,在水热资源丰富的南方海岛,植物具有较大的胸径和小枝含水率、较小的叶片和小枝密度,北方海岛反之。此外,海岛植物的小枝性状(小枝密度和小枝含水率)受年平均风速的影响显著。该研究结果可为海岛植被恢复重建中物种的选择及植被布局规划提供一定的参考。

Plant functional traits and the factors influencing them in the islands of eastern China

Plant functional traits can be used to reflect the responses of plants to environmental changes. In order to understand how plant functional traits change along the environmental gradients and to find the factors driving such changes, especially in the islands of eastern China, six plant functional traits, including diameter at breast height (DBH), tree height (H), mean leaf area (MLA), specific leaf area (SLA), twig wood density (TWD), and twig water content (TWC), were measured in typical plant communities in seven islands. One-way analysis of variance was used to compare the variations in traits among different climatic zones. Stepwise regression analysis was used for quantifying relationships between traits and seven environmental factors (soil total carbon, soil total nitrogen, soil total phosphorus, soil water content, mean annual temperature, mean annual precipitation, and mean annual wind speed). The results showed that:(1) Significant differences exist in most plant functional traits among different climatic zones except SLA, but the functional traits of evergreen and deciduous plants differ among climatic zones, which indicated that plants of different life forms have different reaction and adaptation to the environment. (2) Climatic factors, rather than soil factors, are the main controllers of trait differences along the gradient. Plants in the southern islands have higher DBH and TWC, lower MLA and TWD. The results in northern islands are opposite. Moreover, twig wood traits (TWD and TWC) are significantly influenced by mean annual wind speed in the islands. These results may offer a reference for selecting suitable species for afforestation and reforestation programs in the islands.