北京东灵山不同坡位辽东栎(Quercus liaotungensis)叶属性的比较

植物在山地环境中生存不仅受到海拔等大尺度地形因子的影响,坡位等小尺度地形因子也会对植物产生影响.不同坡位上光照、温度、土壤养分和水分等均会影响到植物的资源利用策略.为比较不同坡位对辽东栎资源利用策略的影响,在北京东灵山海拔1000～1800 m的辽东栎分布范围内针对比叶面积、叶氮含量和叶干物质含量3个重要的叶属性进行了研究.ANOVA统计分析发现,地形和土壤养分及水分等环境因子在不同坡位上出现变化,但只有土壤有机质含量有显著差异.在叶属性中,干物质含量在上坡位最高,下坡位最低,在坡位间差异极显著.比叶面积与叶干物质含量在不同坡位间均成反比关系,在上坡位比叶面积变化一定的情况下,叶干物质含量的变化幅度最小;而比叶面积与叶氮含量仅在上坡位成反比关系.这些结果说明坡位对辽东栎的叶属性有一定的影响,尤其是上坡位的影响最大.

Comparisons on leaf traits of Quercus liaotungensis Koidz. on different slope positions in Dongling Moutain of Beijing

Plant survival in mountain environments is determined by both macro-and micro-scale topographical factors,such as altitude and slope positions.However,how do slope positions affect leaf traits along altitudinal gradient is remained unknown.Specific leaf area,mass-based leaf nitrogen concentration,and leaf dry matter content of Quercus liaotungensis Koidz.were investigated on different slope positions along the altitudinal distribution gradient of the species.The result of ANOVA showed that there were no significant differences of topographical factor and soil nutrient conditions among slope positions,except soil organic matter content.Remarkable distinctions of leaf dry matter content were found among slope positions,and the highest value appeared on top slopes,whereas the lowest on bottom slopes.There were no significant differences of specific leaf area and leaf nitrogen concentration on different slope positions.Specific leaf area had negative correlations with leaf dry matter content on all slopes,however,leaf dry matter content varied least per unit specific leaf area on top slopes.Unlike previous results,specific leaf area correlated negatively with leaf nitrogen concentration on top slopes,while no obvious relationships were found between them on middle and bottom slopes.Slope positions may affect leaf traits and their relationships of Q.liaotungensis,especially top slopes in Dongling Mountain.