重庆缙云山典型林分土壤抗冲性的最佳土壤结构指标研究  

Study on Best Soil Structure Indicators Based on Soil Anti-scourability Under Different Forests

作　　者：郭平[1] 王云琦[1] 王玉杰[1] 张会兰[1] 王冉[1] 胡波[1] 唐晓芬[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《土壤》2014年第1期111-118,共8页Soils

基　　金：中央高校基本科研业务费专项(TD2011-01)资助

摘　　要：应用原状土冲刷法和Le Bissonnais(LB)法中的快速湿润法(FW),对重庆缙云山针阔混交林、常绿阔叶林、楠竹林、灌木林和裸地5种样地的土壤抗冲系数、土壤结构以及两者之间的关系进行研究,以期找出表达不同林分土壤抗冲性的最佳土壤结构指标。结果表明:①不同林分间土壤抗冲系数(L·min/g)大小依次表现为:阔叶林(2.719)>针阔混交林(2.431)>灌木林(2.024)>裸地(1.595)>楠竹林(1.096),各林分土壤抗冲系数除楠竹林和裸地外均从表层到底层呈递减趋势;②对于表达土壤结构常用的4个指标,>0.2 mm团聚体累积量、平均质量直径(MWD)、几何平均直径(GMD)和土壤分形维数(D)在表层(A层)土壤中均表现为:针阔混交林最优,阔叶林优于灌木林,楠竹林和裸地较差;③对土壤抗冲系数和4个土壤结构指标作逐步回归分析,最终平均质量直径(MWD)被引入模型,在显著性水平为P<0.05的情形下,可以认为土壤抗冲系数与MWD存在线性关系,线性回归方程为:y=-0.306+1.823x(R2=0.406,n=19,P=0.003),即在研究地区平均质量直径(MWD)可作为表达土壤抗冲性的最佳土壤结构指标。Using undisturbed soil scour method and the fast wetting method （FW） of Le Bissonnais （LB）, the coefficient of soil erosion, soil structure and the relationship between them were studied at mixed forest, broad-leaved forest, bamboo forest, shrub and bare land in Jin-yun Mountain in order to identify the best soil structure indicators under different forests. The results showed that： 1） the order of different forest soil erosion coefficient （L.min/g） was： broadleaf forest （2.719） 〉 mixed forest （2.431） 〉 shrub （2.024） 〉 bare land （1.595） 〉 bamboo forest （1.096）. The stand soil erosion coefficient had a decreasing trend from the surface to the bottom except bamboo and bare land. 2） For four indicators of soil structure, the cumulative amount of 〉0.2mm aggregates, the average mass diameter （MWD）, geometric mean diameter （GMD） and soil fractal dimension （D） in the surface layer （A layer） soil showed： the mixed forest 〉 broad-leaved forest 〉 shrub 〉 bare poor 〉 bamboo; 3） the coefficient of soil erosion and the four soil structure indicators were conducted stepwise regression analysis. Finally, the average mass diameter （MWD） was introduced into the model. In the case with a significance level of P 〈 0.05, it was thought that soil erosion coefficient and MWD had linear relationship, and the linear regression equation was： y = -0.306＋1.823x（R2 = 0.406, n = 19, P = 0.003）. In the study areas, the average mass diameter （MWD） can be the best soil structure indicator as expression of soil erosion resistance.

关 键 词：土壤抗冲系数 平均质量直径 几何平均直径 分形维数 

分 类 号：S157.5[农业科学—土壤学]