作　　者： ; ; ; ;

机构地区： 广东省生态公益林管理中心

出　　处： 《中南林业科技大学学报》 2010年第5期22-28,共7页

摘　　要： 研究不同林龄桉树林土壤有机碳密度和分布对人工林土壤碳汇研究具有重要意义。2008年12月,在粤西肇庆的1年生和3年生桉树人工林分别设置了100个调查样点,研究土壤有机碳密度随林龄、土层、土壤理化性质、坡位、坡向的变化。结果表明:(1)土壤有机碳密度随土层加深而降低,同一土层在各林龄间差异不显著。样点Ⅰ—A、Ⅰ—B、Ⅲ—A、Ⅲ—B有机碳密度分别为6.87±0.23、4.09±0.10、6.99±0.27和4.02±0.12 kg.m-2。(2)有机碳密度在样点Ⅰ—A、Ⅰ—B、Ⅲ—A、Ⅲ—B均服从正态分布,变异系数分别为23.91%、18.14%、27.00%和21.41%,变异程度皆属于中等变异。(3)除自然含水量和石砾含量外,有机碳密度与土壤理化因子相关性显著或极显著,但不同取样点,土壤有机碳密度与土壤密度、电导率、pH值、土壤氮磷钾全量和有效量的相关性不尽一致;坡度和坡向等地形因子对样点Ⅰ—A、Ⅰ—B土壤有机碳密度影响显著,表现出北坡显著高于南坡,下坡显著高于上坡,对样点Ⅲ—A、Ⅲ—B存在一定影响,但差异不显著。(4)主成分分析表明,土壤理化性质和地形因子可解释有机碳密度47%～60%的信息量,各样点的主要决定因子及作用大小不一致。 Soil organic carbon density（SOCD） and distribution in two different ages（1-year and 3-year old） are of great importance to study soil carbon sequestration of eucalyptus plantation.100 sample plots were set up in eucalyptus plantations of different age in western Guangdong,to analyze the variations of SOCD with age,soil depth,soil physical and chemical properties,aspect,and slope position.The results indicated that（1） SOCD decreased with soil depth and the difference was significant,but the difference between the 1-year old and 3-year old stands is not significant,the SOCD of the sample I-A,I-B,III-A and III-B is 6.87±0.23 kg·m^-2,4.09±0.10 kg·m^-2,6.99±0.27 kg·m^-2 and 4.02±0.12 kg·m^-2,respectively.（2） The SOCD of all sample locations followed a normal distribution and middle heterogeneity degree,with an coefficient of variation（CV） of 23.91 %,18.14 %,27.00 % and 21.41 %,respectively.（3） Correlations analysis showed that SOCD was positively correlated with bulk density,total N,total P,available N,available P,available K,but negatively correlated with total K,and was not significantly correlated with soil water content and gravel content.But relevance degree is inconsistency among sites.At the sites of I-A and I-B,the effects of slopes and aspects on SOCD are significant,that is the SOCD of north slope higher than south slope,and downslope higher than upperslope,but there were no significant difference found at the sites of III-A、III-B.（4） Principal Component Analysis（PCA） further showed that the soil physical and chemical properties and topography（aspect,slope position） accounted for 47 %～60 %of the variance of SOCD.

关 键 词： 生态学 桉树人工林 土壤有机碳密度 影响因素 粤西

领　　域： [生物学] [农业科学] [农业科学]