四川山矾幼树叶功能性状在毛竹干扰下的响应

Response of Leaf Functional Traits of Symplocos setchuanensis Seedling to Different Disturbances Induced by Phyllostachys edulis

设置纯竹林、竹阔林、纯阔林3种毛竹干扰程度的样地,对其内四川山矾幼树叶功能性状的响应进行研究。研究表明:随着毛竹干扰程度的增加,四川山矾幼树比叶面积(SLA)减小,且均达到极显著的水平。从叶片氮(LNC)、磷(LPC)含量来看,随着干扰程度的增加LNC增加,LPC与LNC:LPC总体无显著差异。对叶绿素a(Chla)和叶绿素b(Chlb)的研究表明:随着干扰程度的增加Chla与Chlb减小,Chla/Chlb比值却增加。表明四川山矾幼树叶片功能性状对于毛竹干扰产生一系列适应性变化。从各功能性状间的相关关系来看,毛竹不同干扰程度的样地内Chla与Chlb含量呈极显著的正相关,Chlb和总叶绿素含量均与Chla/Chlb比值呈显著的负相关关系。LNC与SLA,LPC,LNC:LPC呈显著正相关,LPC与LNC:LPC则呈极显著的负相关,说明磷元素在毛竹不同干扰程度的样地中仍是限制元素。试验中叶片氮磷含量与叶绿素含量无明显的相关关系。

Symplocos setchuanensis is a common species in Phyllostachys edulis forests. In order to study the response of leaf functional traits of S. setchuanensis to different disturbances induced by P. edulis, three disturbance degrees （pure bamboo forest, bamboo and broad-leaved forest, and pure broad-leaved forest） of P. edulis were studied. Results showed that specific leaf area （SLA） of S. setchuanensis seedlings decreased significantly with increasing bamboo disturbance degree. Leaf nitrogen content （LNC） increased with increasing disturbance degree, but no significant difference was found between leaf phosphorus content （LPC） and LNC/LPC ratio. In terms of leaf chlorophyll, both chl a and chl b reduced with increasing disturbance degree, whereas an increase in chla/chlb ratio was found. These results showed that leaf functional traits of S. setchuanensis had brought about a series of adaptive changes to disturbances induced by P. edulis. Furthermore, correlation analyses showed that chla and chlb were significantly positively correlated, chlb and total chlorophyll content were significantly negatively correlated with chla/chlb ratio. There was a positive correlation of LNC with SLA, LPC, and LNC/LPC, while LNC/LPC ratio was significantly negatively correlated with LPC, suggesting that phosphorus was still a limiting element in the plots disturbed by P. edulis. However, no correlation was found between LNC or LPC and chlorophyll content in our experiment, and further studies may be needed to explore the reasons.