以重庆四面山不同林地为研究对象,通过亮蓝野外染色示踪实验观测大孔隙流,结合Adobe Photoshop、ERDAS和ArcGIS的图像处理技术分析了阔叶林、针叶林和针阔混交林3种林地的土壤大孔隙分布特征,并探究其影响因子.结果表明:不同林地的大孔隙流形态特征有所不同,大孔隙流的存在使水分在土壤中的运移深度大幅度提高,运移深度规律为阔叶林>针阔混交林>针叶林;不同林地的染色面积比均随着土层深度的增加而减少;较大的孔隙(1级和2级)主要存在于0-20 cm土层,随着土层深度的增加,小孔隙(4级和5级)所占百分比变大;土壤容重、有机质含量、根重密度和根孔数对大孔隙分布均有较大影响,其中,土壤容重与大孔隙数量呈负相关关系,有机质含量、根重密度和根孔数与大孔隙数量呈正相关关系.
Different forest lands on Simianshan mountain in Chongqing were taken as the study objectives. Firstly, by applying brilliant blue dye tracing method, macropore flow was observed and then through using image processing technology such as Adobe Photoshop, ERDAS and ArcGIS, the distribution characteristics of soil macropore in different forests(broadleaf forest, conifer forest and conifer-broadleaf mixed forest) and their influencing factors were analyzed. The results showed that the morphological characteristics of macropore flow of different forests were different. The existence of macropore flow greatly improved the depth of water migration in soil, and the water migration depth in different forests listed in the following order: Broadleaf forest〉conifer-broadleaf mixed forest〉coniferous forest. The proportions of dyeing areas of different forests decreased with the increase of soil depth. Large pores(level 1~2) mainly existed in 0-20 cm soil layer, but with the increase of soil depth, the percentage of small pores(level 4~5) increased. Soil bulk density, organic matter content, root weight density and the number of root holes all showed significant effects on macropore distribution. The number of macropore negatively correlated with soil bulk density, while positively correlated with organic matter content, root weight density and the number of root holes.