都江堰灵岩山3种人工林优势物种叶片的有机组分特征

叶片的有机组分特征不仅是植物光合产物分配策略和养分回收的重要参数,而且是衡量凋落叶分解难易程度的重要指标.为探究不同植物群落叶片间有机组分的差异,以华西雨屏区人工林的优势乔、灌、草植物作为对象,收集其成熟叶及凋落叶,研究其水溶性组分(water soluble component,WSC)、有机溶性组分(organic solvent soluble component,OSC)、酸溶性组分(acid-soluble extractive,ASE)和酸不溶性组分(acid-insoluble residue,AIR)含量特征.结果显示:植物叶片整体的WSC、OSC、ASE和AIR的平均相对含量为分别为25.05%、6.56%、34.30%和35.05%,表现为AIR> ASE> WSC> OSC.成熟叶和凋落叶同种组分的相对含量存在差异,成熟叶中ASE的相对含量(36.34%)最高,凋落叶中AIR含量(39.63%)最高.乔、灌、草层植物成熟叶的WSC、OSC、ASE的相对含量高于凋落叶,而AIR的相对含量低于凋落叶,其中WSC的相对含量在成熟叶和凋落叶间差异显著.不同植物功能群的同一组分间存在差异,木本植物WSC、ASE的相对含量低于草本植物,而OSC、AIR的相对含量高于草本植物.因此,植物叶片的有机组分特征不仅受到叶类型的影响,也受到不同植物功能群的影响;结果可为理解亚热带人工林植物的养分利用效率和凋落物分解机制提供重要理论依据.(图5表1参50)

Characteristics of organic components in the leaves of dominant species in three plantations in Lingyan Mountain of Dujiangyan

The characteristics of organic components in leaves are not only important parameters for the allocation strategy of photosynthetic products and nutrient absorption in plants, but are also important indicators for measuring the difficulty of litter decomposition. We selected the leaves of dominant trees, shrubs, and herbs from the plantations to explore the characteristics of organic components in the leaves of different plant functional groups in the Rainy Area of West China. The mature leaves and senesced leaves of the plants were sampled to analyze the relative contents of water-soluble components(WSC), organic solvent soluble component(OSC), acid-soluble extractive(ASE), and acid-insoluble residue(AIR). The results showed that the relative contents of WSC, OSC, ASE, and AIR in the plant leaves were 25.05%, 6.56%, 34.30% and 35.05%, respectively, and the order ranked as AIR > ASE > WSC > OSC. There were differences in the relative contents of the same component between mature leaves and senesced leaves. The highest relative content of ASE(36.34%) was observed in the mature leaves, while the highest relative content of AIR(39.63%) was observed in senesced leaves. In trees, shrubs, and herbs, the relative contents of WSC, OSC, and ASE in mature leaves were higher than those in senesced leaves, but the opposite situation was observed for the relative contents of AIR. Meanwhile, the relative content of WSC was significantly different between mature leaves and senesced leaves. Additionally, there were differences among the components of different plant functional groups. The relative contents of WSC and ASE in woody plants were lower than those in herbs, while the opposite results were observed in the relative contents of OSC and AIR. These results suggest that the characteristics of organic components in plant leaves are affected not only by leaf type, but also by plant functional groups. This finding can provide an important theoretical basis for understanding the nutrient use efficiency and litter decomposition mechanism of subtropical plantation plants.