Soil distribution relationships as revealed by a global soil database

摘要

Broad quantitative relationships between the environmental factors of climate, parent material and topography and a range of important soil properties and World Reference Base (WRB) soil types were developed using the ISRIC WISE Global soil database Three different analytical approaches were used in the analysis, involving (i) multiple linear regressions, (ii) fitted decision trees and (iii) categorical analysis with median values. Despite the relatively low to moderate strengths of the derived relationships, they can provide useful first approximations of soil character under different environmental conditions and could be applied in broad quantitative soil modelling and mapping programs. They have the potential for widespread application as they should be universally applicable, are based on readily available data and do not require sophisticated quantitative modelling techniques. Most relationships are in accord with accepted pedological thinking and support the state factor model of soil formation, but some anomalies are observed and deserve further examination. The results reveal the dominant influence of climate and parent material in controlling the distribution of many soil properties, with the influence of topography being less evident, at least at the global scale. The WRB soil classification scheme is shown to be least partly guided by genetic factors.