用空间代替时间的方法采样,对陕北榆林地区不同程度沙漠化土壤理化性质、土壤酶活性及其和植物体有机C、全N的关系进行了研究。结果表明,(1)土壤理化性质随沙漠化过程变化呈现规律性的变化。随沙漠化加剧,同一沙漠化梯度不同剖面的pH值随深度增加基本呈增加趋势。随沙漠化程度加剧,土壤脲酶活性急剧降低,随土壤剖面加深,酶活性也呈现明显下降的趋势;土壤过氧化氢酶活性在整个剖面较高,并随剖面深入先降低后升高。(2)相关性分析表明,研究区土壤pH值与其它因子的相关性均不大,除pH值外的其它各因子间存在着密切的相关性;除植物和土壤C/N、土壤容重与其它各指标存在负相关关系外,其它指标间均存在正相关关系。 Using space sampling instead of time, the relationship between physicochemical properties, soil enzyme activities and organic C, total N in desertified soil was studied. The results showed that: (1) Soil physical and chemical properties showed regular changes with the change of desertification process. As the desertification aggravates, the pH value of different sections of the same desertification gradient basically increases with depth. As the extent of desertification intensified, the soil urease activity drastically decreased, with the deepening of the soil profile, the enzyme activity also showed a downward trend; soil catalase activity in the entire profile is higher, and with the depth of the profile first and then increased. (2) The correlation analysis showed that there was not significant correlation between soil pH value and other factors in the study area, and there was close correlation between other factors except pH value. Except plant and soil C / N, soil bulk density and There is a negative correlation between other indicators, and there is a positive correlation between other indicators.