【摘要】 对地处我国西北干旱地区新疆、甘肃、宁夏三省（区）内的１１ 个自然保护区——哈纳斯、小叶白蜡、天山云杉、野核桃、塔里木、东大山、贺兰山、六盘山、崆洞山、兴隆山、莲花山等自然保护区采集的２６０ 个森林土壤样品，进行了生态因子调查；分析了土壤ｐＨ、含水量、水解Ｎ、有效Ｐ、速效Ｋ、全Ｎ、有机质；研究了芽孢杆菌、苏云金芽孢杆菌数量和种类生态分布。共分离苏云金芽孢杆菌４２株，其出土率和分离率分别为１１．５３％ 和２．１８％ 。更多还原

【Abstract】 The 260 forest soil samples were collected from 11 natural reserves of the northwest arid region in China. The soil pH,moisture content,hydrotytic N,efficient P,availabe K, total N, and organic matter of the soils were determined. The ecological factor of 11 natural reserves were also investigated. The number and distribution of both Bacillus and Bacillus thuringiensis were surveyed.The 42 strains of B.thuringensis were isolated from the soil samples.The ratio of the number of the soil samples containing B.thuringensis to number of total soil samples tested is 11.53%. The ratio of the number of B.thuringensis isolated to the number of sporoforming Bacillus examed is 2.18%.更多还原