摘要
选取茂兰自然保护区4种植被类型(原生林、次生林、灌木林和草地),采集0～15 cm的表层土样,探讨了土壤微生物量碳(BC)、土壤微生物量氮(BN)的变化特征及其与土壤理化特性之间的关系。研究发现:(1)样区内生态系统在正向演替中(草地→灌木林→次生林→原生林),BC、BN含量总体表现为逐渐增大,并且冬季最高,夏季最低,不同样地之间差异显著;土壤有机碳和全氮比值(OC/TN)、BC/OC值呈上升趋势,而BC/BN值和BN/TN值呈下降趋势;(2)BC对OC的贡献率为0.8%～1.8%,BN对TN的贡献率为4.1%～7.8%;(3)BC、BN与土壤pH值、OC、TN、碱解氮(AN)、土壤粉粒(0.002～0.02 mm)和<0.25 mm的团聚体之间的相关性达到极显著(p<0.01)或显著水平(p<0.05),且BC、BN之间极显著正相关(p<0.01)。说明研究区BC、BN在冬季是植物生长可利用养分的重要储备库,而夏季是源;并且BC、BN可以作为表征本研究区土壤肥力的敏感因子。
Soil microbial biomass carbon（BC）,nitrogen（BN） and their correlations with soil physico-chemical properties were studied in four sites of the Maolan karst area： virgin forest,secondary forest,shrubbery and grassland.The data from the surface soil samples（the soil depth was 0～15cm） showed that：（1） with positive succession（from grassland to shrubbery,then to secondary forest,and then to virgin forest）,BC and BN increased,and tended to be highest in winter and lowest in summer.Besides,there were significant differences among the four sites.Furthermore,the ratios of soil organic carbon（OC） to total nitrogen（TN） and BC to OC both showed an ascending trend while BC to BN and BN to TN both showed a descending trend;（2） the contributions of BC to OC and BN to TN were 0.8%～1.8% and 4.1%～7.8%,respectively;（3） BC and BN had significant（p0.05） or very significant（p0.01） correlations with soil pH,OC,TN,available nitrogen（AN）,silty particles（0.002～0.02 mm） and microaggregates（0.25 mm）,respectively.Moreover,there was a significantly（p0.01） positive correlation between BC and BN.On the whole,these results suggested that BC and BN acted as the reservoir of plant available nutrients during winter and as the source in summer.In addition,they could be considered as sensitive indicators of soil fertility in the experimental sites.
出处
《地球与环境》
CAS
CSCD
北大核心
2011年第2期188-195,共8页
Earth and Environment
基金
贵州省科技基金资助项目(黔科合J字[2008]2014)
国家自然科学基金创新群体项目(40721002)
中国科学院知识创新工程方向性项目(KZCX2-YW-306)
关键词
喀斯特
土壤微生物量碳
土壤微生物量氮
植被演替
karst
soil microbial biomass carbon
soil microbial biomass nitrogen
vegetation succession
