large and long-lived relative to the magnitude of the initial effects and lifespan of the plants. Guo et al. recently explored quantitative aspects of pedodiversity for the USA based on the State Soil Geographic database (STATSGO). They found that the West USDA-NRCS geographical region has the highest soil taxa richness, followed by the Northern Plains. The South Central region has the highest taxa evenness, while taxa evenness in the West region is the lowest. The West or the South Central regions have the highest overall soil diversity in the four highest taxonomic categories, while the West or Northern Plains regions have the highest diversity in the two lowest taxonomic levels. The high diversity index in the West region results from high taxa richness while the high diversity index in the South Central region results from an evenness of taxa. As the taxonomic level decreases, the pattern of taxa abundance approaches a lognormal distribution. One of the key findings of this research is that at lower levels of soil taxonomic divisions (especially the series level), soil taxa increase continuously with increasing area, indicating considerable soil endemism in the USA (and likely around the world), a key consideration in conservation and preservation planning. However conventional diversity measures, only measure the relative abundance of soil classes, and there is no information on the taxonomic similarity or differences between soil classes. New measures of pedodiversity, such as the mean soil taxonomic distance, which considers both information on the relative abundance and the taxonomic differences between soil classes have been developed and shown to be a better measure. The diversity of soils and landforms has hardly received any attention although their spatial and temporal variation may produce important quantitative and qualitative changes in the landscape. It is only in the last few years that the term diversity has also caught the attention of scientists working on soils and other fields within the earth sciences which creates a forum and research projects on geodiversity. Measurements of diversity were introduced to pedology few years ago. The concept of pedodiversity is now widely accepted within the soil science community. Pedodiversity, as well as biodiversity, may be considered as a framework to analyze spatial patterns, being recognized as a novel pedometric tool. Pedodiversity is a measure of soil variation and also a function of soil formation and development or evolution. Pedodiversity is introduced to pedology to analyze soil spatial