Diversity Indices at Different Geomorphic Units Based on Soil Taxonomy and WRB

Pedodiversity is a way to measure the variation of soils that usually uses soil taxa (taxa is the soil position at categories of a classification system). Various methods including taxonomic pedodiversity (variety of soil classes at a region) is used to investigate the pedodiversity. In this research, richness and diversity indices were investigated in two Soil Taxonomy and World Reference Base (WRB) classification systems at rock pediment, mantled pediment, piedmont and alluvial plain geomorphic units. 26 pedons were digged and sampled at the different geomorphic units and classified based on Soil Taxonomy and WRB classification systems. Calculation of diversity indices occurred considering number of soil profiles and their extension area at different categories of Soil Taxonomy System (order to family) and WRB (tier 1 and 2).Results showed that diversity indices increased from higher to lower categories in each two systems and indices based on profile number were higher than those of based on soil type area. Results of this research also showed that pedodiversity is more clear by using soil taxonomy so that it causes higher richness and diversity indices. In the other word, soil taxonomy has more efficiency to diagnose intensity of soil changes and soil complexities at the study area. This result means that at a region with given area, Soil Taxonomy has a higher ability to distinguish between different types of soils and this ability is better shown in areas with high pedological complexity.

Keywords:

Taxonomic Categoties , Diversity Index , Soil Classification Systems , Soil Richness , Geomorphic Unit