中文摘要：

选择不同林龄和栽培代次的杨树人工试验林地，从2009年2月至2009年12月分层采集土壤样品，分析了土壤微生物量磷（SMBP）的年动态变化和剖面垂直分布特征，结果表明，各试验林地SMBP的年动态变化规律相似，即冬、春季节较高，而夏、秋季节较低。1a中，2月SMBP含量最高，各试验林地不同土层的平均含量分别为24．52mg／kg（0～10cm）、17．75mg／kg（10～20cm）和12．19mg／kg（20—40cm）；10月含量最低，平均分别为11．45mg／kg（0—10cm）、7．37mg／kg（10～20cm）和2．66mg／kg（20—40cm）。随着杨树人工林林龄和栽培代次的增加，SMBP的含量呈下降趋势。随着土层的加深，SMBP含量降低，在整个试验期内各试验林地0—10cm土层的SMBP含量分别比10～20cm和20—40cm土层平均高出5．00mg／kg和14．21mg／kg（农田无林地），8．79mg／kg和16．42mg／kg（1代6年生林地），4．87mg／kg和9．80mg／kg（1代10年生林地），7．20mg／kg和9．64mg／kg（2代5年生林地），4．74mg／kg和6．80mg／kg（2代8年生林地）。相关分析显示，SMBP含量与土壤有机质、全氮和全磷呈极显著相关，而与土壤有效磷含量无显著相关。

英文摘要：

Polar plantation sites with different stand ages and rotations were selected to study the dynamics and the distribution characteristics of soil microbial biomass phosphorus （SMBP） from February 2009 to December 2009 in north Jiangsu. The results showed that the annual dynamics of SMBP were similar for all experimental sites, in which the contents of SMBP were higher in winter and spring than in summer and autumn. The contents of SMBP at February were the highest and the average contents of five sites at different soil layers were 24.52 mg/kg （0 - 10 cm）, 17.75 mg/kg （ 10 - 20 cm） and 12.19 mg/kg （20 -40 cm）, while the contents of SMBP at October were the lowest and the average contents of five sites were 11.45 mg/kg （0 - 10 cm）, 7.37 mg/kg （ 10 - 20 cm） and 2.66 mg/kg （20 - 40 cm）. The content of SMBP was decreased with the increase of stand ages and rotations of poplar plantation. The results also displayed that the contents of SMBP were decreased with the increase of soil depth in the profile. The average content of SMBP at 0 - 10 cm was 5.00 mg/kg and 14.21 mg/kg higher than that at 10 - 20 cm and 20 -40 cm for agricultural farm without forest, 8.79 mg/kgand 16.42 mg/kg for the farm with rotation - 1 forest aged 6 , 4.87 mg/kg and 9.80 mg/kg for the farm with rotation - 1 forest aged 10, 7.20 mg/kg and 9.64 mg/kg for the farm with rotation - 2 forest aged 5, 4.74 mg/kg and 6.80 mg/kg for the farm with rotation - 2 forest aged 8, respectively. Analysis indicated that the content of SMBP was significantly correla- ted with the content of soil organic matter, total nitrogen and total phosphorus, but not with the soil available phosphorus.