摘要
以受季节性冻融过程影响显著的东北地区的黑土、暗棕壤和水稻土为例,采用实验室模拟的方法,研究交替冻融循环过程(分别在-20℃和20℃下处理)对土壤腐殖质的影响。研究表明:交替冻融后,黑土和暗棕壤松结态腐殖质质量分数分别增加了39%和28%,HA/FA分别上升了45%和35%;水稻土松结态腐殖质质量分数和HA/FA分别下降了18%和31%。三维荧光结果进一步验证,黑土、暗棕壤在交替冻融中土壤芳香化程度增高,HA/FA上升,而水稻土则相反。黑土和暗棕壤松结态腐殖质和HA/FA升高,主要是微生物分解作用和土壤大团聚体破坏等原因造成,水稻土松结态腐殖质和HA/FA降低,主要是水稻土的缺氧环境造成。
In order to study the effects of freeze-thaw cycles(FTCs) on the active humus(AH) and the ratio of humic acids to fulvic acids concentration(HA/FA) in black soil(BS),dark brown soil(DS) and paddy field soil(PS),indoor simulating experiments were carried out.The result showed,after FTCs treated by-20 ℃ to 20 ℃,AH and HA/FA increased 39% and 45% in BS sample.In DS samples,AH and HA/FA increased 28% and 35%.However,AH and HA/FA decreased 18% and 31% in PS sample.The result of EEM fluorescence spectra showed the molecular weight of humic substances in BS and DS samples increased.In contrast,the molecular weight of humic substances in PS samples decreased or changed little.During FTCs,soil organic matter was decomposed by microorganism,which could improve AH and HA/FA.The anoxic conditions was probably the reason why AH and HA/FA decreased in PS samples.
出处
《生态环境学报》
CSCD
北大核心
2010年第12期2870-2874,共5页
Ecology and Environmental Sciences
基金
国家水体污染控制与治理科技重大专项(2009ZX07207-001)
财政部改革启动专项(GGQD2008-04)
关键词
交替冻融
土壤
松结态腐殖质
胡敏酸/富里酸
三维荧光
freeze-thaw cycles
soil
active humus
the ratio of humic acids to fulvic acids concentration(HA/FA)
three-dimensional excitation-emission-matrix fluorescence spectroscopic(EEM)