北京小西山山前洪积扇不同土地利用方式下的土壤微形态特征

通过对北京小西山山前代表性洪积扇的观察研究,探索不同土地利用方式对土壤微形态特征的影响。通过对土壤薄片的观察,分析土壤微形态特征;用ENVI及MATLAB软件处理图片,并对孔隙度进行定量分析。结果表明:1)林地(WL1)剖面表层土壤微结构为海绵状结构,而园地(WL2)和菜地(WL3)的表层土壤多呈整块状结构或孔道结构;2)各采样点土壤矿物成分相近,但骨骼颗粒形态特征有较大差异。3)WL1剖面土壤孔隙度较高,以面状孔隙为主,WL2和WL3剖面土壤孔隙度过低,以中小孔隙居多。研究认为:1)林地的土壤微结构较园地和菜地的好,由于人类的不合理利用和管理,园地和菜地使土壤微结构变差,土壤孔隙度下降。2)各采样点土壤成土母质相似,土壤骨骼颗粒形态差异受到不同土地利用方式下人类干扰程度差异的影响。

Soil micromorphological features in different land use patterns on the proluvial fans in front of Xiaoxishan Mountain of Beijing

In this paper,the effect of different land use patterns on the soil microstructures was studied.Nikon polari-microscope was used to observe the soil regolithes.Observation and quantitative analysis of soil voids were carried out by using the MATLAB and ENVI image processing system.There are 3 results in this study.1)Soil microstructure of profile WL1 which is forest land is spongy,but profile WL1 and WL2 which are garden and vegetable fields are always blocks.2)The mineral composition of the profiles is similar,but the shapes of the soil particles are different.3)Porosity of profile WL1 is higher than that of WL2 and WL3.The former has many area holes,while WL2 and WL3 have many small and medium holes.It is concluded that the soil microstructures of forest are better than that of garden and vegetable fields.The soil microstructures become worse due to unreasonable use and poor management.Parent materials of all the profiles are resemble.The different shapes of soil particles result from the degrees of human interference.