北京市平原造林典型困难立地土壤质量评价

Soil Quality Evaluation for Typical Difficult Sites of Afforestation in Beijing Plain

积极开展困难立地土壤质量评价、分析林分持续健康经营的关键限制性因子,是实现平原造林低维护高服务可持续健康经营的现实需求,可为北京市平原区困难立地的土壤改良提供科学依据。通过取样调查典型困难立地的土壤样本,获取土壤样品,室内测定土壤物理、化学因子共19项指标,运用矩阵加权以及常用函数得出典型困难立地土壤质量评价与各地区相对应的限制性因素分析。结果表明:(1)北京平原地区土层薄,部分地区土层仅有20～30 cm;(2)土壤黏性差,保水保肥性差;(3)土壤质量指数总体排序为通州台湖>顺义顺平路>大兴瀛海>密云西田各庄>丰台槐房>房山长阳>怀柔北房>通州西集>大兴北臧村。可见:(1)大兴北臧和房山长阳的土壤质量限制因子为土壤质地,怀柔北房和密云西田的是土层厚度,大兴瀛海和丰台槐房的为土壤密度,通州西集和顺义顺平的为土壤养分,通州台湖为饱和导水率;(2)北京地区平原造林立地条件相差较大,需针对不同限制性因子,采取对应性措施予以改良。

Actively carrying out soil quality assessment of difficult sites and analyzing the key restrictive factors of sustainable health management of forest stands are the practical needs for achieving low-maintenance and high-service sustainable and healthy management of plain afforestation, and can provide scientific basis for soil improvement in difficult sites in the plain area of Beijing. Soil samples from typical difficult sites were sampled, soil samples were obtained, and 19 indicators of soil physics and chemical factors were determined indoorally. Matrix weighting and common functions were used to obtain soil quality assessment of typical difficult sites and corresponding restrictive factors in each region. analysis. The results show these as follows.① The soil layer in the plain of Beijing is thin, and the soil layer is only 20~30 cm in some areas;② The soil viscosity is poor, and the water retention and fertility are poor;③ The overall ranking of soil quality index is Tongzhou Taihu>Shun Yishun Ping Road>Daxing Bohai>Miyun Xitian Grange>Fengtai Yifang>Fangshan Changyang>Huairou North Room>Tongzhou Xiji>Daxing Beijiao Village. It can be seen that:① The soil quality limiting factor of Daxing Beibei and Fangshan Changyang is soil texture, the thickness of soil layer in Huairou Beifang and Miyun Xitian, the soil density of Daxing Bohai and Fengtai boudoir, Tongzhou Xiji and Shunyi Shunping, the soil nutrient is the saturated water conductivity of Tongzhou Lake;② The conditions of the afforestation site in Beijing area are quite different, and corresponding measures should be taken to improve the different restrictive factors.