冻融作用对土壤微团聚体特征及分形维数的影响  

EFFECTS OF FREEZING-THAWING ON CHARACTERISTICS AND FRACTAL DIMENSION OF SOIL MICROAGGREGATES

作　　者：王展[1] 张玉龙[1] 虞娜[1] 邹洪涛[1] 

机构地区：[1]沈阳农业大学土地与环境学院,沈阳110866

出　　处：《土壤学报》2013年第1期83-88,共6页Acta Pedologica Sinica

基　　金：国家973项目(No.2004CB418504)资助

摘　　要：为了研究冻融作用对土壤微团聚体特征和分形维数的影响,本试验以东北地区典型土壤-棕壤为研究对象,通过室内人工控温冻融培养,测定分析不同含水量条件下,不同冻融频次处理后土壤水稳性微团聚体组成、平均质量比表面积(MWSSA)、平均质量直径(MWD)和分形维数(D)等特征指标。结果表明:供试土壤经冻融循环处理后,不同粒级微团聚体含量的变化趋势不尽相同,除0.005～0.001 mm外,含水量对其他粒级微团聚体含量的影响均达到了显著或极显著影响,冻融次数对各级微团聚体含量均达到了显著或极显著影响;土壤平均质量比表面积随着冻融次数和土壤含水量的增加先减小后增加;土壤平均质量直径随冻融次数的增加先增加后减小,随土壤含水量的增加先减小后增加;分形维数随着冻融次数的增加先减小后增加,随土壤含水量的增加呈波动式变化。冻融处理使土壤微团聚体的稳定性先增强后减弱,适宜含水量可增加土壤微团聚体的稳定性。In order to study effects of freezing-thawing on characteristics and fractal dimensions of soil microaggregates, samples of brown soil, typical of Northeast China, were collected and subjected to an indoor artificial freezing and thawing test for analysis and determination of composition, mean weight soil surface area （MWSSA） , mean weight diameter （MWD） and fractal dimension （D） of soil microaggregates as affected by frequency of freezing and thawing and water content. Results show that changes in these characteristics of soil microaggregates after the treatment varied from fraction to fraction of particle-size. The effect of water content on content of soil microaggregates was significant or extremely significant in all fractions, except the fraction of 0. 005 - 0. 001 mm, and so was the effect of the frequency of freezing and thawing. WMSSA first decreased and then increased with increasing freezing-thawing frequency and soil water content. WMD first increased and then decreased with increasing freezing-thawing frequency, but went the other way round with increasing soil water content. And D first decreased and then increased with increasing freezing-thawing frequency, and fluctuated with increasing soil water content. It was found that the treatment first enhanced and then undermined the stability of soil microaggregates and a proper soil water content could improve the stability.

关 键 词：冻融作用 土壤 微团聚体 分形维数 

分 类 号：S152.4[农业科学—土壤学]