闽西南红壤侵蚀区黑莎草功能性状特征及其与土壤因子的关系

Functional Traits of Gahnia tristis and Its Relationship with Soil Factors in the Red Soil Erosion Area of Southwestern Fujian

摘要:

为了解黑莎草(Gahnia tristis)在南方红壤侵蚀区的适应状况，测定了长汀县红壤侵蚀区的黑莎草叶片、根系的功能性状及土壤理化性质，并应用数理统计方法分析了黑莎草叶片与根系功能性状之间的相关性，及其对土壤因子的响应。结果表明，黑莎草叶片表型性状在冬夏季间存在显著差异，叶长、叶宽、叶组织密度和叶绿素表现为夏季显著大于冬季，根系表型性状则更具稳定性，冬季的根系养分含量均高于夏季，养分的分配上叶片养分高于根系养分。叶组织密度与叶绿素含量呈显著正相关，与比叶面积呈显著负相关；根组织密度与比根长和比根面积均呈显著负相关，叶片和根系养分间均呈显著正相关，土壤碳、氮、磷含量是影响黑莎草功能性状主要因子。因此，黑莎草可通过调节功能性状以适应环境变化，可作为地带性植物应用于南方红壤侵蚀区的植被恢复和水土流失治理。

Abstract:

In order to understand the adaptation of Gahnia tristis in the red soil erosion zone of southern China, the functional traits of leaves and roots of G. tristis, and the physicochemical properties of soil were determined and their correlations and the responses of leaves and roots of G. tristis to soil factors were analyzed by using mathematical statistics method. The results showed that there were significant differences in phenotypic traits of Gahnia tristis leaves between winter and summer, leaf length, leaf width, leaf tissue density and chlorophyll content were significantly higher in summer than those in winter, while the root phenotypic traits were more stable. The nutrient content of roots in winter was higher than that in summer, and the nutrient allocation in leaves was higher than that of roots. Leaf tissue density had positive correlation with chlorophyll content and negative with specific leaf area. There was significant negative correlation between root tissue density and specific root length and specific root area, and significant positive correlation between leaf and root nutrients. Soil carbon, nitrogen, and phosphorus contents were the main factors affecting the functional properties of G. tristis. Therefore, it was suggested that G. tristis could adapt to environmental changes by adjusting its functional traits, which could be used as a zonal plant for vegetation restoration and soil erosion control in the red soil erosion areas of south China.