摘要
通过原位试验,对华西雨屏区不同密度[833株·hm 2（A1）、1 333株·hm 2（A2）、2 222株·hm 2（A3）]巨桉（Eucalyptus grandis）人工林土壤有机碳和微生物生物量碳氮动态特征进行了研究.结果显示：（1）各密度巨桉林分土壤有机碳含量在夏季和秋季较高,春季和冬季较低,但季节变化相对平稳,而它们土壤有机碳含量年平均值分别为22.54 g· kg 1（A1）、19.76 g·kg 1（A2）、16.84g· kg1（A3）,且密度间差异达到显著水平.（2）各密度林分土壤微生物生物量碳氮呈现出与土壤有机碳相似的规律性季节变化,随着林分密度增加,林下土壤微生物生物量碳氮含量减小.（3）土壤微生物熵一年内的波动较小,分别处于2.30％～2.44％ （A1）、2.14％～2.39％ （A2）、2.47％～2.69％ （A3）之间.（4）各密度林分土壤微生物生物量碳氮含量与其立地土壤有机碳、水解氮、有效磷、速效钾均存在显著相关关系.研究表明,华西雨屏区不同密度巨桉人工林土壤有机碳含量、微生物生物量碳氮含量、微生物熵季节变化相对平稳,但受到人工林密度的显著影响,并随巨桉密度增加土壤有机碳含量、微生物生物量碳氮含量有降低的趋势.
With in situ experiment,the soil organic carbon （SOC）,microbial biomass carbon （MBC） and microbial biomass nitrogen （MBN） were analyzed in Eucalyptus grandis plantations with different stand densities（A1：833 tree· hm-2,A2：1 333 tree· hm-2 andA3：2 222 tree· hm-2） in Rainy Area of Western China.The results were given as follows：（1）SOC in every stand with different densities were higher in summer and autumn,lower in spring and winter,but seasonal changes was relatively stable.The annual average SOC was 22.54 g· kg-1（A1）,19.76 g· kg-1（A2）,16.84 g· kg-1（A3）,andthe difference between the density reached significant level; （2）MBC and MBN exhibited a clear seasonal pattern in every stand with different densities,the same as the SOC,with the increase of the density,soil microbial biomass carbon and nitrogen content were less; （3）The fluctuations of microbial quotient were slightly in the plantations with different densities.The microbial quotient fluctuated between 2.30％-2.44％（A1）,2.14％-2.39％ （A2） and 2.47％ 2.69％0（A3）,respectively.（4）The part of MBC（N） with SOC,available N（P,K） had a significant relation in different densities （P＜0.05）.Consequently,the seasonal changes of the E.grandis plantation SOC,MBC,MBN and the microbial quotient were relatively stable,but the different stand density had a significant effect on them,and with the increase of density,the content of soil organic carbon,microbial biomass carbon and nitrogen decreased in Rainy Area of West China.
出处
《西北植物学报》
CAS
CSCD
北大核心
2014年第7期1476-1481,共6页
Acta Botanica Boreali-Occidentalia Sinica
基金
“十一五”国家科技支撑计划(2006BAC01A11,2008BADC2B01)
关键词
巨桉人工林
土壤有机碳
土壤微生物生物量碳
土壤微生物生物量氮
Eucalyptus grandis plantation
soil organic carbon
soil microbial biomass carbon
soil microbial biomass nitrogen
