摘要：
The contents,storage and distribution of SOC and TN in the period of successive planting Eucalyptus were studied with the substitution method of space for time based on different generations (first-,second-and third-generations) Eucalyptus plantations and nearby Pinus massoniana plantation at Dongmen Forest Farm in Guangxi as objects.Following results were concluded:(1)The SOC content (0-20 cm) in P.massoniana plantations and the first,the second and third generations of Eucalyptus plantations was 17.06,15.70,14.47 and 13.16 g/kg,respectively,and the TN content (0-20 cm) was 0.895,0.841,0.778 and 0.715 g/kg,respectively.The contents of SOC and TN obviously decreased as continuous planting rotations increased.But there was no significant difference in the content of SOC and TN in the 20-40 cm soil.(2)The SOC storage amounts was 66.84,56.57,52.97 and 50.81 t/hm2,and the TN storage was 3.78,3.33,3.09 and 2.98 t/hm2,respectively.There were significant differences in the SOC and TN storage between P.massoniana plantation and the second and third generations Eucalyptus plantations (p＜0.05).(3)The correlation analysis showed that the SOC content was positively correlated (p＜0.01) with TN content in different generations Eucalyptus plantations,and there was also a significant correlation between SOC,TN and C/N (p＜0.05).%采用时空互换法,以广西东门林场不同栽植代数(1、2和3代)桉树人工林和邻近区域马尾松人工林为研究对象,分析桉树人工林连栽过程中土壤有机碳、全氮含量和储量及其分布特征.结果表明:(1)在0～20 cm土层,马尾松和1代、2代、3代桉树人工林有机碳含量分别为17.06、15.70、14.47和13.16 g/kg,土壤全氮含量分别为0.895、0.841、0.778和0.715 g/kg,均呈现随栽植代数的增加而下降的趋势,但在20～40 cm土层,马尾松和各栽植代数桉树林土壤有机碳和全氮含量无显著差异.(2)马尾松、1代、2代和3代桉树人工林0～40 cm土壤有机碳储量分别为66.84、56.57、52.97和50.81 t/hm2,土壤全氮储量分别为3.78、3.33、3.09和2.98 t/hm2,其中马尾松林和2、3代桉树林有机碳和全氮储量之间存在显著性差异(p＜0.05).(3)相关分析表明,马尾松和不同栽植代数桉树人工林土壤有机碳含量与全氮含量均存在极显著相关性(p＜0.01),土壤有机碳、全氮与C/N之间也存在显著的相关关系(P＜0.05).
