热带雨林木质藤本植物叶片性状及其关联

热带雨林中木质藤本植物较为丰富。随着全球气候变化加剧,木质藤本植物的丰富度具有不断增加的趋势,有可能对热带森林的结构、功能和动态产生重要影响。然而,目前对木质藤本响应环境变化的机制所知甚少。本研究以13个科20种热带雨林常见木质藤本植物为材料,测定了冠层叶片的17个形态特征及结构性状,并分析了性状间的相互关系。结果表明,叶片相对含水量的种间变异最小（变异系数为5%）,而上表皮厚度的种间变异最大（变异系数为80%）,其它性状的种间变异系数为24%~61%。木质藤本植物的叶脉密度、叶片密度均与气孔密度呈显著正相关,叶片干物质含量与比叶面积呈显著负相关。与相同生境的树木相比,木质藤本的叶面积更小、气孔密度和叶片密度更低、比叶面积更高,但两种植物类群的叶片横切面组织结构厚度无显著差异。研究结果对理解木质藤本植物的生态适应性具有重要意义。

Leaf Traits and Their Associations among Liana Species in Tropical Rainforest

Lianas are abundant in tropical rainforest. With global climate change, liana density and biomass are increasing. This can significantly influence co-occurring tree recruitment, growth, mortality and survival, which, in turn, may have a significant effect on the structure, functioning and dynamics of tropical forests. In this study, we measured 17 leaf traits of 20 tropical rainforest liana species from 13 families and analyzed trait associations across lianas. Our results showed that relative water content of liana leaves exhibited the smallest interspecific variation, with a coefficient of variation （CV） of 5%, adaxial epidermis thickness presented the largest interspecific variation （CV of 80%）, with the CV of the other 15 traits ranging from 24% to 61%. Across the lianas studied, both vein density and leaf density were positively correlated with stomatal density; and, specific leaf area was negatively correlated with leaf dry matter content. Compared with trees growing in the same habitats, lianas had lower values for leaf area, stomatal density and leaf density, but higher specific leaf area, with no significant differences in leaf anatomical traits between lianas and trees. These results are essential for understanding the ecological adaptation of lianas in tropical rainforest.