黄土高原子午岭不同森林群落叶功能性状

Leaf functional traits of different forest communities in Ziwuling Mountains of Loess Plateau

对黄土高原子午岭地区5种主要森林群落中重要值>0.1的物种叶功能性状进行了比较,结果表明:1)叶干物质含量(LDMC)与比叶面积(SLA)呈负相关;SLA与叶厚度(LT)呈负相关,但与叶氮含量(LNC)和叶磷含量(LPC)呈正相关;LT与LNC、LPC和叶钾含量(LKC)呈负相关;LNC、LPC和LKC三者之间均呈正相关。2)坡位是影响叶大小(LS)、LT、LNC和LKC的主要地形因子,海拔对LPC和SLA的影响最大,而坡向则是影响LDMC的主要因子。因此,叶功能性状之间所呈现的特征及其对立地条件的适应都表现出了植物的生态策略。3)各群落间的乔木层叶功能性状均有显著差异,灌木层的叶功能性状无显著差异,而草本层除了LDMC无显著差异(P>0.05)外,其他叶功能性状均有显著差异,说明群落的叶功能性状的大小取决于群落内物种的叶功能性状及其重要值。

A comparative study was made on the leaf functional traits of the plant species whose importance value is 〉0. 1 in five main forest communities in Ziwuling Mountains of the Loess Plateau. For the test plant species, their leaf dry matter content （ LDMC ） had significant negative correlation with specific leaf area （SLA） , SAL was significantly negatively correlated with leaf thickness （LT） but positively correlated with leaf nitrogen content （ LNC ） and leaf phosphor- us content （ LPC）, LT was significantly negatively correlated with LNC, LPC, and leaf potassium content （LKC） , and there were significant positive correlations among LKC, LPC, and LNC. Slope position was the main terrain factor affecting leaf size, LT, and LNC, elevation had greater effects on LPC and SLA, while slope direction was the main factor affecting LDMC. The relation- ships among the leaf functional traits and the adaptation of the leaf functional traits to terrain factors showed the ecological strategy of the plant species. The leaf functional traits of the plant spe- cies in tree layers of the forest communities had significant differences, those in shrub layers had little difference, and the leaf functional traits except LDMC of the plant species in herbage layers had significant differences. Our results suggested that the leaf functional traits of forest community depended on the leaf functional traits of the plant species in the community, and on the importance value of the plant species.