滇东北4种类型筇竹林分土壤碳氮磷生态化学计量特征研究

以滇东北4种类型筇竹林分的土壤为研究对象，比较分析了各类型筇竹林土壤在0～20、20～40、40～60 cm土层深度中的土壤C、N、P含量及其化学计量比，阐明不同类型筇竹林土壤C、N、P含量及其化学计量比的垂直变化规律，探讨筇竹林生态系统中C、N、P元素的循环及反馈机理。结果表明：4种类型筇竹林土壤C含量无显著差异，N、P含量差异性显著；不同类型筇竹林在各土层的土壤C、N、P含量分别在21.8～75.64、1.56～5.90、0.45～1.35 g/kg之间，且土壤C、N、P含量均表现为筇竹–阔叶树混交林˃筇竹纯林。4种不同类型筇竹林的土壤C、N、P化学计量比具有显著差异性，且土壤C/N、C/P、N/P值的变化范围分别为6.22～18.06、19.46～109.26、1.97～6.05，筇竹纯林土壤C/N、C/P、N/P的比值大于其他3种筇竹–阔叶树混交林。4种不同类型筇竹林的土壤C、C/P间及土壤N、P间呈极显著正相关，土壤C与N、N/P间及土壤N、N/P间则是显著正相关，筇竹–阔叶树混交林中土壤C、C/P间、土壤N、N/P间呈极显著正相关，筇竹纯林中，土壤N、C/P间具有显著相关关系。因此，筇竹–阔叶树混交林的土壤C、N、P肥力高于筇竹纯林，表明筇竹–阔叶树混交林可有效改善林地土壤肥力状况，可作为滇东北地区植被恢复的优良营造模式。本研究有利于揭示滇东北筇竹林生态系统的土壤养分状况，对筇竹林的经营管理、养分调控及生产力提高等具有指导作用。

Ecological Stoichiometry of Soil C,N and P in 4 Different Types of Qiongzhuea tumidinoda Forests in Northeast Yunnan

This paper takes the soil of 4 different types of Qiongzhuea tumidinoda forests in northeastern Yunnan as the research object, and compares and analyzes the soil C, N, and P contents in the soil depths of 0–20, 20–40 cm, and 40–60 cm for each type of Q. tumidinoda forest and its stoichiometric ratio. The vertical variation of soil C, N, P content and stoichiometric ratio in different types of Q. tumidinoda forest was clarified, and the cycle and feedback mechanism of C, N and P elements in Q. tumidinoda forest ecosystem were explored. The results showed that there were no significant difference in soil C content among the 4 types of Q. tumidinoda forests, but significant differences in N and P content. The soil C, N and P contents of different types of Q. tumidinoda forests in each soil layer were 21.8–75.64, 1.56–5.90 g/kg and 0.45–1.35 g/kg, respectively. And soil C, N, and P contents all showed the mixed forest of Q. tumidinoda and broad-leaved tree ˃ the pure forest of Q. tumidinoda. The stoichiometric ratios of soil C, N, and P in the 4 different types of Q. tumidinoda forests were also significantly different, and the variation ranges of soil C/N, C/P, N/P values were 6.22–18.06, 19.46–109.26 and 1.97–6.05, respectively. The soil C/N, C/P, and N/P ratios of the pure forest of Q. tumidinoda were higher than those of the other 3 mixed forests of Q. tumidinoda and broad-leaved trees. There were extremely significant positive correlations between soil C and C/P and between soil N and P in the 4 different types of Q. tumidinoda forests. There were significant positive correlations between soil C and N, N/P and between soil N and N/P. There was a very significant positive correlation between soil C, C/P, soil N, and N/P in mixed Q. tumidinoda and broad-leaved forest, and there was a significant correlation between soil N and C/P in pure Q. tumidinoda forest. Therefore, the soil C, N, and P fertility of the mixed forest of Q. tumidinoda and broad-leaved tree were higher than those of the pure forest of Q. tumidinoda, indicating that the mixed forest of Q. tumidinoda and broad-leaved tree could effectively improve the soil fertility of the woodland, and could be used as an excellent model for vegetation restoration in northeastern Yunnan. This study is beneficial to reveal the soil nutrient status of the Q. tumidinoda forest ecosystem in northeastern Yunnan, and has a guiding role in the management, nutrient regulation and productivity improvement of the Q. tumidinoda forest.