桂北岩溶区青冈栎-青檀群落植物叶片比叶面积研究

Plant specific leaf areas of Cyclobalanopsis glauca-Pteroceltis tatarinowii community in karst region, northern Guangxi

关键词:  岩溶  生活型  群落  比叶面积  叶片厚度

Key words:  karst  life form  community  specific leaf area  leaf thickness

摘要:

为揭示岩溶地区植物叶片比叶面积变化规律和叶片形态之间的相关关系,研究了桂北岩溶区青冈栎-青檀群落的叶片长/宽(LL/LW)、叶片厚度(LT)和比叶面积(SLA)及其之间的关系。结果表明:群落中常绿树种的LL/LW和LT显著高于落叶树种,而常绿树种的SLA显著低于落叶树种; 乔木和灌木之间的LL/LW存在显著差异,但SLA和LT不存在显著差异。总体上看,SLA与LL/LW、LT之间是显著负相关关系,SLA随着LL/LW、LT的变大而逐渐减小。但LT与SLA负相关趋势比LL/LW与SLA的明显。因此,LT比LL/LW对叶片SLA的影响大,其明显影响了叶片的SLA。SLA的大小是衡量叶片获取光照能力的指标,因此岩溶区植物较厚的叶片对光照的获取能力具有较大的影响,并可导致光合作用效率的降低。

Abstract:

In order to reveal the variable character of plant specific leaf areas and its correlation with leaf shape in karst region,the ratio of leaf length to leaf width(LL/LW),leaf thickness(LT)and specific leaf area(SLA)and its relationship of the leaves of Cyclobalanopsis glauca—Pteroceltis tatarinowii community in northern Guangxi were investigated. The results showed that the LL/LT and LT of evergreen species were significantly higher than that of the deciduous trees,SLA of evergreen species was significantly lower than that of the deciduous trees. And LL/LW was significantly different between the arbors and shrubs,while SLA and LT were not significantly different. While,the coefficient of correlation between LT and SLA was larger than that of between LL/LW and SLA,and LT had larger impact on SLA than LL/LW. Furthermore,LT significantly affected SLA in this study. Previous researches showed that the index of SLA was the indicator measuring the ability of capturing the sun's energy for leaves. The thicker leaves were,the larger impacted on ability of obtaining sunlight. Therefore,it would lead to reduce the efficiency of photosynthesis.