江苏宝华山主要常绿植物叶寿命与虫食频度相关性

Correlation of leaf lifespan of major evergreen trees with herbivory frequency in Baohuashan,Jiangsu Province

研究叶寿命与叶片虫食相关性对揭示常绿树种的生活史特征及生态适应机制具有重要意义。采用静态生命表和野外观测分析江苏宝华山5个主要树种叶寿命及虫食频度,并对叶属性进行室内测定。结果表明：1）5个树种叶预期寿命不同（P〈0.05）,介于1.26-2.47 a,平均1.80 a。2）不同树种叶片虫食频度不同,平均为34.74%,且同一树种现存叶片的虫食频度随叶片龄级的增大而增大。3）5种植物的叶寿命和虫食频度存在显著正相关（P〈0.05）。叶片硬度、厚度、含水量和LMA之间存在显著相关性,其主成分分析结果表明：第1主成分贡献率达92.57%,并且虫食频度与第1主成分呈显著负相关（P〈0.05）。因此推测,亚热带常绿、落叶阔叶混交林中不同常绿植物,其叶寿命越长,虫食频度也越高;其虫食作用不仅与物种的多度有关,而且与不同叶属性的综合作用（而非单一叶属性）有密切关系。

The study of correlation between leaf lifespan and herbivory plays a significant role in reflecting their life history features and ecological adaptive mechanisms. The methods of static life table and field observation were applied to analyze the leaf lifespan and herbivory frequency of five major evergreen broad-leaved species sampled from Baohuashan Nation Forest Park,Jiangsu Province; meanwhile their leaf traits were also measured indoors. The results were as follows： 1）The leaf lifespan of the five species was different（ P 〈0. 05）,varying from 1. 26 to 2. 47 years with an average of 1. 80 years. 2） The herbivory frequencies of the five species were different,with an average of 34. 74%. Moreover,for each species,the herbivory frequencies of extant leaves on one branch increased with increasing the leaf age class. 3） There was a significant positive correlation between the herbivory frequency and the leaf lifespan（ P 〈0. 05）. Significant correlations were found between leaf toughness,thickness,water content and LMA（ leaf mass per area）. Principal component analysis on those leaf traits showed that the first principal component could explain 92. 57% of the total variance. Furthermore,the herbivory frequency had a significant negative correlation with the first component（ P 〈0. 05）. Therefore,it is concluded that the longer the leaf lifespan,the higher the herbivory frequency for woody evergreen species in evergreen and deciduous broad-leaved mixed forests in subtropics,and that the herbivory frequency is not only correlated with abundances of tree species,but also with a range of leaf traits（ rather than a single one）.