【摘要】 2022年8月份，在黑龙江省齐齐哈尔市克山县境内的克山农场，选择位置相邻，坡度、坡向、坡长、林龄基本一致的樟子松水土保持林、杨树水土保持林、坡耕地(对照)为研究对象；在选定的坡面上沿着和坡面等高线垂直的方向分别布设3条样线作为3个重复，每2条样线之间间隔3 m,每条样线从坡顶至坡底分别设置10个取样点，每个取样点之间间隔30m;使用环刀法，按照土层深度(h)采集土壤表层(0<h≤15 cm)、下层(15 cm<h≤30 cm)土样，放在通风处自然风干后过2.00、0.15 mm土壤筛，测定土壤微团聚体的粒径分布、比表面积、土壤理化性质；运用体积分布模型计算不同粒径土壤颗粒体积分形维数(D值),比较不同树种水土保持林的土壤微团聚体粒径组成、微团聚体分形维数的坡面分布特征，分析土壤理化性质与土壤微团聚体粒径组成、微团聚体分形维数之间的相关性。结果表明：坡面主要土壤养分质量分数，全磷质量分数(土壤表层、下层),由大到小依次为耕地、杨树林地、樟子松林地；有效磷质量分数(土壤表层、下层),由大到小依次为耕地、樟子松林地、杨树林地；有机质质量分数，土壤表层由大到小依次为杨树林地、樟子松林地、耕地，土壤下层由大到小依次为杨树林地、耕地、樟子松林地。分形维数，与有效磷质量分数、全磷质量分数、微团聚体颗粒比表面积显著相关；分形维数在一定程度上可用于表征土壤的养分状况；土壤下层整个坡面，坡耕地的分形维数明显小于樟子松林地、杨树林地的分形维数，说明水土保持林的林下土壤的土质优于耕地；根据坡面土壤微团聚体分布特征及其趋势、坡面养分分布特征综合对比，杨树林地土质优于樟子松林地。更多还原

【Abstract】 In August 2022, in Keshaan County, Qiqihar City, Heilongjiang Province, China, the study focused on the adjacent locations within Keshaan Farm, with similar slope, slope direction, slope length, and forest age. The study objects included Pinus sylvestris water and soil conservation forest, Populus water and soil conservation forest, and sloping farmland(contrast). Three transects were established along the contour lines perpendicular to the slope, with a spacing of 3m between each pair of transects. Each transect consisted of 10 sampling points, spaced 30 m apart from the top to the bottom of the slope. Using the ring knife method, soil samples were collected at different depths(h) including the surface layer(0<h≤15 cm) and the lower layer(15 cm<h≤30 cm). After naturally drying in a ventilated place, the soil samples were sieved through 2.00 mm and 0.15 mm soil sieves to determine the particle size distribution, specific surface area, and physicochemical properties of soil microaggregates. The volume distribution model was used to calculate the fractal dimension of soil particle volume with different particle sizes(D value). The slope distribution characteristics of soil microaggregate particle size composition and microaggregate fractal dimension of different tree species for water and soil conservation forest were compared, and the correlation between soil physicochemical properties, and soil microaggregate particle size composition and microaggregate fractal dimension was analyzed. The results showed that the content of major soil nutrients and total phosphorus(surface layer and lower layer soil) on the slope were highest in the cultivated land, followed by Populus forest and P. sylvestris forest. The content of available phosphorus(surface layer and lower layer soil) was highest in the cultivated land, followed by P. sylvestris forest and Populus forest. The content of organic matter in the surface layer was highest in the Populus forest, followed by P. sylvestris forest and cultivated land, while in the lower layer, it was highest in the Populus forest, followed by cultivated land and P. sylvestris forest. The fractal dimension was significantly correlated with the content of available phosphorus, total phosphorus, and specific surface area of microaggregate particles. The fractal dimension can be used to some extent to characterize the nutrient status of soil. The fractal dimension of the entire slope in the lower layer was significantly smaller in the cultivated land than in the P. sylvestris forest and Populus forest, indicating that the soil quality of the forest under water and soil conservation was better than that of the cultivated land. Based on the comprehensive comparison of the distribution characteristics and trends of soil microaggregates and nutrient distribution characteristics on the slope, the soil quality of the Populus forest was better than that of the P. sylvestris forest.更多还原