不同地质背景下土壤溶解有机碳含量的季节动态及其影响因子  

Seasonal change and the influence factors of soil dissolved organic carbon at different geological background

作　　者：黄黎英[1] 曹建华[1] 周莉[1] 徐祥明[1] 莫彬[1] 张佩[1] 

机构地区：[1]国土资源部岩溶动力学重点实验室

出　　处：《生态环境》2007年第4期1282-1288,共7页Ecology and Environmnet

基　　金：国家自然科学基金项目(40372116)

摘　　要：为了解岩溶区和非岩溶区土壤溶解有机碳(DOC)含量及其季节动态是否存在差异,为今后相关研究提供研究依据,作者用0.5mol·L-1K2SO4浸提法分析测定了广西桂林市灵川县潮田乡毛村由泥盆系融县组灰岩(D3r)发育石灰土、砂页岩(D2l)发育红壤中溶解有机碳的含量及其季节动态变化,并分析了其与影响因子的相互关系。结果表明:石灰土中溶解有机碳的质量分数为:19.3675～143.2524mg·kg-1,红壤的为:221.1652～1016.602mg·kg-1,石灰土因其偏碱、高钙镁、高有机质含量的特性而使得DOC含量远低于非岩溶区红壤的含量;石灰土和酸性土DOC含量在秋季都达到最高值,在冬季或春季含量最低;在空间分布上都随土壤深度增加而降低。岩溶区及非岩溶区土壤DOC含量的季节动态变化可以划分为4个阶段:①9—10月高温少雨,植物凋落物增多,DOC含量在一年中最高;②11月-12月,气温迅速降低,微生物活性随之降低,DOC含量下降;③12月底—4月,前期(12月至次年2月)DOC浓度随土壤有机质含量的增加而增加;后期(3—4月)气温回升,降雨频繁,生物复苏,生物活动旺盛,土壤DOC含量迅速增加;④5—8月,高温多雨,DOC转化为CO2释放出来,部分DOC随雨水淋失,土壤中DOC总含量不高。　To understand the dissolved organic carbon’s seasonal dynamic change in the soil of karst and non-karst region,and reveal if there is any difference between the two kinds of soils,we distilled and Determined the concentrations of the dissolved organic carbon （DOC） in lime soil from limestone （D3r） and in red soil from sandstone and shale containing iron ore （D2l） at Mao village,Chaotian town,Lingchuan County,Guilin,Guangxi China with 0.5mol·L^-1 K2SO4,and mensurated the relations between DOC and its influenced factors,so as to provide some scientific foundation for future relational research. The results showed that： the contents of DOC in lime soils were from 19.367 5 to 143.252 4 while in red soils were from 221.165 2 to 1 016.602. With the specialties of high pH,high contents of Ca and Mg,the contents of DOC in lime soils were smaller than that in red soils. The DOC content both had the highest value in the autumn,the lowest level in the winter or spring,and decreased with the increasing of soil depth in spatial distribution in two kinds of soils. The seasonal change of DOC content in lime soil and red soil in a year can both be divided into four stages： （1） September to the middle of October,DOC had the highest value in the year with high temperature,less rainfall and increasing plants litters; （2） November to mid-December,the activity of microbial biomass fell,so result in the decline of DOC content; （3） The end of December to April,the concentration of DOC increased with increasing of soil organic matter content from December to February. In March to April,the temperature rose,rainfall was frequently,all lives came round,microbial biomass decomposed organic matter into DOC,and plant root system excreted more substances,so DOC content in soil increased rapidly; （4） from May to August,it was hot and rainy,DOC was decomposed by microbial biomass and changed into CO2,part of DOC lost with water at heavy rainfall,so the DOC content in soil was not high.

关 键 词：溶解有机碳 石灰土 酸性土 季节动态 影响因子 

分 类 号：X14[环境科学与工程—环境科学]