黄雍容 黄石德 高伟 林捷

摘要：本文以虎伯寮南亚热带季雨林林下植被为研究对象，对灌木层和草本层优势植物各器官C、N和P含量进行测定，对其生态化学计量特征及其养分利用策略进行研究。结果表明，灌木层优势植物C含量显著高于草本层，草本层植被N和P含显著大于灌木层。灌木层优势植物各器官C含量差异不显著，叶的 N含量显著高于其它器官，叶的P含量显著高于干和根。草本层优势植物地上部分的C、N和P含量均高于地下部分，仅N含量差异达显著水平。化学计量结果表明，该群落灌木层优势植物的N、P利用效率较草本层优势植物高，灌木层和草本层植物生长受P元素限制。灌木层优势植物的干器官以及草本层地下部分N、P利用效率较高。

关键词：虎伯寮;灌木层;草本层;器官;化学计量

Abstract：In order to understand the ecostoichiometric characteristics and nutrient utilization strategy of the understory vegetation of south subtropical monsoon forest in Huboliao， the carbon （C）， nitrogen （N）， phosphorus （P） concentrations of different organs of the dominant plants in shrub layer and herb layer were explored. The results show that （1） the C content of the shrub layer was significantly higher than the herb layer， yet the N and P contents of herb layer were significantly higher than the shrub layer. （2）In the dominant plants of shrub layer， the C content of the stem had no significant difference between the organs. the N contents of the leave was significantly higher than that of other organs， and the P content of the leave was significantly higher than that of stem and root. （3） In the dominant plants of herb layer， the C， N and P contents of the upground part were all higher than those of the underground part， but only significant difference in N content. （4） Base on stoichiometry， the N and P’s utilization efficiency of dominant plants in shrub layer were higher than those in herb layer， the growth of plants in shrub layer and herb layer were restricted by P-element， the N and P’s utilization efficiency of the stem of the dominant plants in shrub layer were high， as so as those of the underground part of herb layer.

Key words： Huboliao;shrub layer;herb layer;organ;stoichiometry characteristics;

生態化学计量学是生态学和化学相结合用于研究生态过程中多重化学元素平衡关系的的学科[1]，从元素比率的角度统一不同层次的研究结果[2]，目前已在生态学各尺度（生态系统、区域、群落、种、个体）的研究中广泛应用。内稳性理论和生长速率理论是生态化学计量学的重要基础，研究表明化学计量内稳性与优势物质有显著相关关系，对于生态系统结构、功能和稳定性研究有重要意义[2]。不同研究尺度不同研究对象的生态化学计量特征有差异，目前在区域、群落、功能群等尺度关于生态化学计量学特征已开展大量的工作[3-6]，在限制性养分判断的应用上形成较为一致的认识。……