南方红壤侵蚀区芒萁叶片对微地形的响应

Responses of Dicranopteris pedata leaves to micro-topographyin red soil erosion region of South China

关键词:  芒萁, 微地形, 功能性状, 环境因子, 南方红壤侵蚀区

Key words:  Dicranopteris pedata, micro-topography, functional trait, enviromental factor, red soil erosion region of South China

摘要:

植物功能性状可以反映植物应对环境变化的响应策略。该文以芒萁为研究对象,主要采用单因素方差分析和冗余分析,比较了3种微地形(沟脊、沟壁、沟底)中环境因子和芒萁叶片功能性状的差异,分析了芒萁对浅沟微地形的响应及其适应策略。结果表明:(1)芒萁叶片功能性状的总体变异程度在0.05～0.47之间,叶厚和叶面积均表现为沟底>沟壁>沟脊(P<0.05),沟壁的叶氮含量显著高于沟脊和沟底,沟脊的叶磷含量显著低于沟壁和沟底,比叶面积和叶碳含量在3种微地形间均无显著差异。(2)沟脊的芒萁通过减小叶面积来降低水分散失进行自我保护,沟壁的芒萁通过增加叶氮含量来提高叶片光合速率而促进生长,沟底的芒萁通过增大叶面积来提高光捕获能力而促进生长。综上结果认为,土壤养分和温湿条件的差异,促使芒萁通过调节营养物质含量和改变叶片形态以更好地适应环境。

Abstract:

Plant functional traits can reflect response strategies of plants to environmental changes. In this study, we used a one-way ANOVA and redundancy(RDA)to compare the differences in leaf functional characters of Dicranopteris pedata in three micro-topographies(ridge, slope and valley of the ephemeral gully)and to analyze the response and adaptation strategy of D. pedata to shallow trench micro-topography. The results were as follows:(1)The overall variation degree of leaf functional characters of D. pedata was between 0.05 and 0.47. Both leaf thickness and leaf area were showed as the order of valley > slope > ridge(P<0.05). The leaf N content at the slope was significantly higher than that at the ridge and valley. The leaf P content was significantly lower at the ridge than those at the slope and valley. There was no significant differences in specific leaf area and leaf C content among three micro-topographies.(2)D. pedata at the ridge reduced water loss to protecte itself by reducing leaf area. D. pedata at the slope increased the photosynthetic rate of leaves to promote growth by increasing the N content of leaves. D. pedata at the valley improved light capture ability to promote growth by increasing the leaf area. The above results indicate that due to the differences of soil nutrients, temperature and humidity conditions, D. pedata can achieve better adaption to the environment by adjusting nutrient content and changing leaf morphology.