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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∶4 000 000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∶50 000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.m-3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∶1 000 000和1∶4 000 000土壤数据库下与1∶50 000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∶1 000 000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 in terrestrial ecosystems plays an important role in soil fertility conservation and ecological environment protection. However, the past national or regional scale estimates of phosphorus reserves do not consider differences caused by different scales of soil database. Taking a sample of more than 3.9 million hm2 dry land in 29 counties (or cities) of northern Jiangsu as an example, the paper analyzes more than 17 000 plots and 963 profiles and can comprehensively reflect the 1:50 000 database of the spatial heterogeneity of soil attributes and the current domestic Effects of up to 1: 1 000 000 and 1: 4 000 000 soil databases on phosphorus estimates for similar studies. The results showed that total phosphorus density and reserves estimated from different mapping datum soil databases differed greatly. Total phosphorus density and reserves in 1:50 000 soil database were 1.34 kg.m-3 and 10.52 Tg, respectively, while 1: 1 000 000 And 1: 4 000 0002 soils, P density and reserves were 0.79 kg.m-3 and 6.02 Tg, 0.77 kg.m-3 and 6.26 Tg, respectively, far less than 1:50 000 Total phosphorus in soil database . From different types of soils, the cinnamon soil was the most affected by the mapping scale. The relative deviations of total phosphorus density and reserves from 1: 000 000 and 1: 4 000 000 soil databases and 1:50 000 soil databases were 80% -90% and Between 7% and 130%, the relative area deviations from the 1: 50000 total phosphorus density and reserves in the soil samples of 1: 1 000 000 and 1: 4 000 000 soil databases with the largest area reached 38% -39% and 21 % ~ 23%. From each county (city) point of view, the relative deviations of total phosphorus density and reserves from 1:50 000 soil data under the 1: 1 000 000 and 1: 4 000 000 soil databases mostly exceeded 40%. This also shows that the use of different mapping scales of soil database will have a great impact on the estimation of phosphorus reserves and phosphorus in dry land. Therefore, it is imperative to use a more detailed soil database in future studies of total phosphorus density and reserve estimation at the national and regional scales.