四川盆地西缘不同功能型树种凋落叶功能性状特征

Leaf Litter Traits of Different Functional Tree Types on the Western Edge of the Sichuan Basin

【目的】为了解华西雨屏区亚热带不同植物功能型树种凋落叶功能性状特征,探讨不同植物功能型树种对环境的适应策略。【方法】以四川盆地西缘都江堰灵岩山亚热带森林群落为研究对象,采集了18种树种凋落叶,分为常绿阔叶、落叶阔叶和针叶3个植物功能型,比较分析碳(C)、氮(N)、磷(P)、木质素和纤维素及其化学计量比在不同功能型树种间的变异。【结果】常绿阔叶和落叶阔叶树种凋落叶N含量显著低于针叶树种,C∶N比显著高于针叶树种;常绿阔叶树种凋落叶P含量显著低于落叶阔叶和针叶树种;不同功能型树种间凋落叶C含量、C∶P和N∶P比无显著差异;落叶阔叶树种木质素含量显著低于常绿阔叶和针叶树种,常绿阔叶和落叶阔叶树种凋落叶纤维素:N比显著高于针叶树种;而纤维素含量和木质素:N比在不同功能型树种间无显著差异。【结论】四川盆地西缘不同植物功能型树种之间凋落叶功能性状差异显著,这可能影响区域森林群落养分循环机制。

【Objective】The aim of this study was to investigate the leaf litter traits of different functional types in subtropical regions of rainy area of west China,and to explore their adaptation strategy to environmental conditions.【Method】This study was carried out in a subtropical forest community of Lingyan Mountain in Dujiangyan on the western edge of the Sichuan Basin.Leaf litters of 18 tree species were collected.The investigated trees were divided into three types:evergreen broad-leaved,deciduous broad-leaved and coniferous plant,according to the plant functional types.The differences of carbon(C),nitrogen(N),phosphorus(P),lignin and cellulose content and their stoichiometric ratios among different functional types were compared and analyzed.【Result】Litter of evergreen broad-leaved and deciduous broad-leaved species exhibited lower N content and higher C∶N ratio than those of conifers.Litter of evergreen broad-leaved species relative to deciduous broad-leaved and coniferous species had significantly lower P content.There was no significant difference in litter C content,C∶P and N∶P ratios among three types of trees.Deciduous broad-leaved trees showed lower litter lignin content compared with evergreen broad-leaved and coniferous trees.Litter cellulose:N ratio of evergreen broad-leaved and deciduous broad-leaved trees was significantly higher than that of conifers,while the cellulose content and lignin:N ratio were not significantly different among the three plant functional types.【Conclusion】The litter functional characteristics were significantly different among the plant functional types on the western edge of the Sichuan Basin,which might influence the diverse nutrient cycling mechanism of forest communities in the region.