陆地生态系统中的磷元素在土壤肥力保持和生态环境保护方面起着重要的作用,但以往国家或区域尺度磷储量估算并没有考虑不同尺度土壤数据库所造成的差异.文章以江苏北部29个县(市)390多万hm2旱地为例,分析了17 000多个图斑和963个剖面组成、能详尽反映土壤属性空间异质性的1∶50 000数据库与目前国内同类研究使用最多的1∶1 000 000和1∶4000000土壤数据库对磷储量估算的影响.结果表明,不同制图尺度土壤数据库估算的全磷密度和储量差异很大,1∶50000土壤数据库下的全磷密度和储量分别为1.34 kg·m-3和10.52 Tg,而1∶1 000 000和1∶4 000 0002个土壤数据库下磷密度和储量分别为0.79 kg·m3和6.02 Tg、0.77 kg·m-3和6.26 Tg,远小于1∶50 000土壤数据库的全磷密度和储量.从不同土壤类型看,褐土受制图比例尺影响最大,1∶1 000000和1∶4000000土壤数据库下与1∶50000土壤数据库全磷密度和储量相对偏差分别在80%～90％和7％～130％之间,面积最大的潮土在1∶1 000 000和1∶4 000 000土壤数据库下与1∶50 000全磷密度和储量相对偏差也分别达到38％～39％和21％～23％.从各个县(市)来看,1∶1 000000和1∶4 000 000土壤数据库下与1∶50 000土壤数据全磷密度和储量相对偏差大多超过40％.这也说明使用不同制图尺度土壤数据库将对旱地磷储量和磷密度的估算结果造成很大的影响.因此,在今后的国家和区域尺度全磷密度和储量估算研究中使用更详细的土壤数据库是非常必要的.%Phosphorus plays a central role to maintain soil fertility and protect the ecological environment, but previous studies were primarily limited to single mapping scale, the influence of usage of different series mapping scale databases on soil total phosphorus storage was not clear. For this application, three types of spatial soil databases of 1 : 50 000, 1 : 1 000 000 and 1 : 4 000 000 were used to support soil total phosphorus storage estimates. The soil database of 1 : 50 000 contained 17 024 polygons of upland soils representing 963 upland soil profiles, which is the most detailed soil data for the 3.9 Mha of upland soils in the north of Jiangsu province. The soil databases of 1 : 1 000 000 and 1 : 4 000 000 was widely used and coarsed soil data source when soil total phosphorus storage estimates was applied to the national or regional scale in China. Results showed that the phosphorus density and phosphorus storage were 1.34 kg·m-3 and 10.52 Tg, 0.79 kg·m-3 and 6.02 Tg, 0.77 kg·m-3 and 6.26 Tg, of soil database of 1 : 50 000 1 : 1 000 000 and 1 : 4 000 000 respectively. As for soil subgroups, the highest relative deviation of was linked to brown soil accounting for about 80%-90% and 7%-130% of phosphorus density and phosphorus storage at different mapping scales, respectively. The most common soil in the area was moisture soil, which accounted for about 53% of the total area of upland soils with the relative deviation of 38%-39% and 21%-23% of phosphorus density and phosphorus storage at different mapping scales, respectively. As for administrative area, the relative deviation of most counties was high 40% of phosphorus density and phosphorus storage at different mapping scales. This indicated that the more precise soil database was necessary to better estimate phosphorus density and phosphorus storage from upland soils at the regional or national scale.
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