Abstract: In order to investigate the effects of land use patterns on soil properties in the low hilly areas of Northwestern Liaoning Province,we collected soil samples from adjacent grassland,woodland,and cropland in Kazuo,a county of Chaoyang,and measured soil physical and chemical properties and microbial communities. Results showed that grassland soil had the lowest total phosphorus,available phosphorus,and nitrate nitrogen content,while the cropland soil had the lowest total nitrogen,ammonium nitrogen,and total carbon content. For bacteria communities,woodland soil had the highest relative abundance of Rhizobiales,whereas cropland soil had the highest relative abundance of Sphingomonadales. As for fungal communities,woodland soil had the highest relative abundance of Sordariales and cropland soil had the highest relative abundance of Pleosporales. Chao1 index and observed species number of soil bacteria and fungi in cropland were significantly lower than those in woodland (P<0.05). Cropland soil demonstrated higher abundances of the glyoxylate cycle and carbohydrate degradation,but lower abundances of the pentose phosphate pathways and carbohydrate biosynthesis. In conclusion,compared with grassland and woodland soil,cropland soil showed disrupted aggregate structure,serious nitrogen loss,decreased soil microbial diversity,and a microbial structure that favored nitrogen emission and carbon decomposition.

Key words: Land use patterns, Soil physicochemical properties, Soil bacteria, Soil fungi, Function prediction

摘要： 为探究土地利用方式对辽西北低山丘陵区土壤性质的影响，以喀左县为研究样点，采集毗邻草地、林地和农田的土壤，测定其理化性质和微生物群落结构。结果表明：草地土壤的全磷、速效磷和硝态氮含量最低，农田土壤全氮、铵态氮和全碳含量最低。细菌群落中，林地土壤根瘤菌目的相对丰度最高，农田土壤鞘脂单胞菌目的相对丰度最高；真菌群落中，农田土壤粪壳菌目的相对丰度最高，林地格孢腔菌目的相对丰度最高。农田土壤细菌和真菌的Chao1指数和观测物种数显著地低于林地（P<0.05）。农田土壤微生物的乙醛酸循环和碳水化合物降解等途径丰度较高，但磷酸戊糖途径和碳水化合物合成等途径的丰度较低。综上，与草地和林地相比，农田土壤氮素流失严重，土壤微生物多样性下降，微生物群落趋向于增强土壤氮挥发和碳分解，不利于氮积累和碳固存。

关键词: 土地利用方式, 土壤理化性质, 土壤细菌, 土壤真菌, 功能预测