不同光环境下枫香幼苗的叶片解剖结构

落叶阔叶树种枫香是常绿阔叶林的优势种之一。对比研究了重庆丰都世坪林场不同光环境下枫香幼苗叶片的解剖特征,结果表明:1)旷地枫香叶片的厚度大,气孔个体较大且排列紧密,栅栏组织发达,具有明显的旱生叶特征;而林下的枫香叶片明显变薄,气孔小且排列稀疏,海绵组织发达,具有一定的阴生叶特征;2)不同光环境下,气孔密度、栅栏组织的厚度和层数、栅栏细胞长度以及栅栏组织与海绵组织厚度比(P/S)等具有较高的可塑性,表明这些因素对于枫香适应不同光环境具有较大的作用;3)从叶片解剖特征与功能的统一来看,阳性树种枫香幼苗更适合生长在旷地等高光生境中,而不易生长在郁闭的林下;4)落叶阔叶树种在中亚热带常绿阔叶林群落恢复与演替中具有重要作用。

Responses of seedling leaf anatomical structure of Liquidambar formosana, a deciduous broadleaf tree, to different light regimes

Liquidambar formosana,a deciduous broadleaf tree,is one of the dominant species in evergreen broadleaved forest.A comparative study on its seedling leaf anatomical characteristics under different light regimes in the Shiping Forest Farm of Fengdu County,Chongqing City showed that:(1)In open site,the leaf was thicker,stomatal apparatus was bigger and arranged closely,and palisade tissue was well-developed,demonstrating obvious xerophyte traits;but in understory,the leaf thickness decreased significantly,stomatal apparatus was smaller and arranged sparsely,and spongy tissue was well-developed,showing some shady plants' characters.(2)Under different light regimes,the stomatal density,palisade tissue thickness and layers,palisade cell length,and palisade/spongy ratio had greater plasticity,indicating the greater roles of these anatomical characters in the adaptation of L.formosana seedlings to varied light regime.(3)Based on the relations between leaf anatomical characters and functions,L.formosana seedlings were more adapted to high-light regimes such as open site,but not to understory.(4)Deciduous broadleaved tree played an important role in the community restoration and succession of mid-subtropical evergreen broadleaved forest.