【摘要】 【目的】土壤碳氮磷化学计量特征能够有效地指示土壤营养状况以及养分间的耦合关系。旨在探究毛竹扩张及去除过程中土壤养分分布格局及其生态化学计量特征变化，在江西齐云山国家级自然保护区内建立阔叶林、竹阔混交林和纯毛竹林3种林分类型的样地。【方法】采用时空替代法模拟毛竹向阔叶林扩张过程，并通过人工伐除的方式去除混交林和毛竹林内毛竹。采集毛竹扩张及去除过程中样地内0～10 cm和10～20 cm土壤样品，测定其理化性状及碳氮磷化学计量比。【结果】毛竹向阔叶林扩张会导致土壤含水率、pH、NH4+-N含量升高，有效磷含量在0～10 cm土层升高。对竹阔混交林和毛竹林伐竹100%处理后土壤含水率在0～10 cm土层均显著降低。C/N在毛竹扩张和去除过程中均无显著性变化。C/P在纯毛竹林伐竹100%处理后0～10 cm土层显著降低，在竹阔混交林毛竹去除过程中0～10 cm和10～20 cm土层C/P均表现出先升高后降低的趋势。N/P的变化趋势与土壤TN含量变化趋势一致，表明当毛竹扩张样地内N/P<14时，毛竹扩张和去除过程中N/P主要是由土壤氮素进行调控。【结论】以上变化过程探明了毛竹扩张及去除过程的驱动机制，即毛竹通过改变土壤C、N、P化学计量特征进行扩张，引起植物体C、N、P元素及其化学计量比发生转变。为评价毛竹扩张及去除的生态效应以及有效防治扩张具有非凡意义。更多还原

【Abstract】 [Objective]The stoichiometric characteristics of soil carbon,nitrogen,and phosphorus can effectively indicate the soil nutritional status and the coupling relationship among nutrients. To explore the distribution pattern of soil nutrients and the changes in ecological stoichiometric characteristics during the expansion and removal of moso bamboo,sample plots of three forest stand types,namely broad-leaved forest,bamboo-broadleaf mixed forest,and pure moso bamboo forest,were established in the Qiyunshan National Nature Reserve,Jiangxi Province.[Method]The expansion process of moso bamboo into broad-leaved forests was simulated using the space-for-time substitution method,and moso bamboo within mixed forests and moso bamboo stands was removed through manual cutting.Soil samples at depths of 0-10 cm and 10-20 cm within the sample plots during the expansion and removal of moso bamboo were collected,and their physicochemical properties and stoichiometric ratios of carbon,nitrogen,and phosphorus were determined.[Result]The results indicate that the expansion of moso bamboo into broad-leaved forests led to an increase in soil moisture content,pH,and NH4+-N content,and an increase in available phosphorus content in the 0-10 cm soil layer.After 100% bamboo cutting in bamboo-broadleaf mixed forests and moso bamboo forests,the soil moisture content in the 0-10 cm soil layer decreased significantly. There was no significant change in the C/N ratio during the expansion and removal of moso bamboo.The C/P ratio in the pure moso bamboo forest decreased significantly after 100% bamboo cutting in the 0-10 cm soil layer.During the bamboo removal process in the bamboo-broadleaf mixed forest,the C/P ratio showed a trend of first increasing and then decreasing in both the 0-10 cm and 10-20 cm soil layers.The change trend of the N/P ratio was consistent with that of soil TN content,indicating that when the N/P ratio in the moso bamboo expansion sample plots was <14,the N/P ratio during the expansion and removal of moso bamboo was mainly regulated by soil nitrogen.[Conclusion]The above change process has clarified the driving mechanism of the expansion and removal of moso bamboo,that is,moso bamboo expands by altering the stoichiometric characteristics of soil C,N,and P,causing changes in the elements of C,N,and P and their stoichiometric ratios in plants.This is of great significance for evaluating the ecological effects of the expansion and removal of moso bamboo and for effectively preventing and controlling its expansion in the future.更多还原