Soil Indicators of Eco-geographical Regionalization in Mid-temperate Zone of Eastern China

Eco-geographical region system is an important result of China's regionalizational development quantitatively, systematically and dynamically. In order to probe into the topic thoroughly, based on the data from the second China's national soil survey and the provincial soil resource information, by principal analysis and discriminant analysis, this paper discusses the appropriate soil indicators as the complement of eco-geographical region indicator systems and the relationship between these soil indicators and soil types in regionalization. The results show that five soil indicators are used in eco-geographical regionalization in mid-temperate zone of eastern China, which are the content of organic matter, cation exchange content, pH, clay capacity and soil bulk density in topsoil. With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern China are compiled with a resolution of 1 km in every grid and the indicative meaning of these soil indicators is discussed. By a cluster analysis, it is proved that these soil indicators are better than the soil types and soil regionalization in delineating eco-regionalization zones.