华北刺槐林与自然恢复植被土壤微生物量碳、氮含量四季动态  

Seasonal Dynamics of Microbial Biomass Carbon and Nitrogen in Soil of Robinia pseudoacacia Forests and Near-Naturally Restored Vegetation in Northern China

作　　者：王风芹[1] 田丽青[1] 宋安东[1] 桑玉强[2] 张劲松[3] 高峻[3] 

机构地区：[1]河南农业大学生命科学学院农业部农业微生物酶工程重点实验室,郑州450002 [2]河南农业大学林学院,郑州450002 [3]中国林业科学研究院林业研究所国家林业局林木培育重点实验室,北京100091

出　　处：《林业科学》2015年第3期16-24,共9页Scientia Silvae Sinicae

基　　金：林业公益性行业科研专项项目(201404206-03;201104008)

摘　　要：【目的】土壤微生物量碳、氮是植被所需碳、氮的重要＂源＂或＂库＂,是公认的综合评价土壤质量或肥力的重要指标,也是土壤生态系统变化的预警及敏感指标,研究其动态变化,可为退耕还林及后期管理决策提供科学依据,并为深入研究林地碳氮循环及温室气体排放提供参考。【方法】以农田（FL）为对照,研究华北土石山区10年生刺槐林、43年生刺槐林、自然恢复植被（NRV）土壤微生物量碳、氮的四季动态变化,并对各样地微生物量碳、氮对土壤营养库的贡献率进行对比研究。【结果】各样地微生物量碳、氮随土层加深而逐渐下降,其季节动态变化差异显著;农田、自然恢复植被、10和43年生刺槐林地0-20 cm土层微生物量碳、氮含量四季均值分别为251.94,290.68,150.66,197.34 mg·kg^-1和30.95,46.46,36.55,45.27 mg·kg^-1。其中：自然恢复植被的微生物量碳、氮含量四季均值最高,其微生物量碳含量分别是农田、10和43年生刺槐林的1.15,1.93和1.47倍,微生物量氮含量分别是它们的1.50,1.27和1.03倍;土壤微生物量碳、氮含量随刺槐树龄增大而升高,43年生刺槐林0-20 cm土层的微生物量碳、氮含量是10年生刺槐林的1.31和1.24倍。各植被样地不同层次土壤微生物量碳氮比季节差异明显,农田、自然恢复植被、10年和43年生刺槐林0-20 cm土层碳氮比四季均值分别为8.64,6.26,4.12和4.36;10,43年生刺槐林碳氮比分别是农田的0.48和0.50倍,是自然恢复植被的0.66和0.70倍。在0-20 cm土层中,农田、自然恢复植被、10和43年生刺槐林地微生物量碳对土壤有机碳平均贡献率分别为1.88%,2.00%,1.54%和1.24%,土壤微生物量氮对土壤全氮的平均贡献率分别为1.21%,5.44%,3.55%和2.26%。【结论】各样地土壤微生物量碳、氮之间显著相关,它们与土壤全氮、有机质和速效钾含量均显著相关;除此之外,土壤微生物量碳还与土壤硝态氮�【Objective】Microbial biomass carbon and nitrogen are an important ＂source＂or ＂storeroom＂for vegetation＇s requirements. They are important index of comprehensive evaluation of soil quality or fertility,and also sensitive earlywarning indicators of soil ecosystem. This study aims at providing a scientific basis for converting farmland to forests and making decisions of forest management,and providing basis for further study on the C and N cycle and greenhouse gas emission at forestland. 【Method】Seasonal dynamics of soil microbial biomass C and N and their contribution rates to soilnutrition pools in the Robinia pseudoacacia plantation land with tree ages of 10-year-old（ RP10） and 43-year-old and naturally restored vegetation（ NRV） were studied and compared to those of the farmland（ FL） in the rocky mountain region of northern China. 【Results】Microbial biomass C and N of all lands were sharply decreased with increasing soil depth. Seasonal dynamics of microbial biomass C and N contents were different significantly among all these lands. Soil microbial biomass C and N contents in 0- 20 cm soil layer of FL,NRV,RP10 and RP43 were 251. 94,290. 68,150. 66,197. 34 mg·kg^-1and 30. 95,46. 46,36. 55,45. 27 mg·kg^-1,respectively. Soil microbial biomass C and N contents of NRV were much higher than that of other lands,1. 15,1. 93,1. 47 times,and 1. 50,1. 27,1. 03 times of that in FL,RP10 and RP43,respectively. Microbial biomass C and N contents in 0- 20 cm soil layer in RP43 were significantly higher than that of RP10（ 1. 31 and 1. 24 times,respectively）,indicating an increase with forest age.Seasonal dynamics of microbial biomass C- N ratio were different significantly among all lands,and the seasonal means of FL,NRV,RP10 and RP43 were 8. 64,6. 26,4. 12 and 4. 36,respectively. Soil microbial biomass C-N ratio of RP10 and RP43 were 0. 48 and 0. 50 times of that of FL,0. 66 and 0. 70 times of NRV. The average contribution rates of soil microbial biomass C to soil organic carbon in FL,NRV,

关 键 词：华北土石山区 退耕还林 刺槐 自然恢复植被 微生物量碳/氮 

分 类 号：S718.5[农业科学—林学]