Soil and geomorphology diversity and soil landscape evolution in the arid region of Bam, south-east Iran

Knowledge about spatial soil variation in terms of measured pedodiversity offers the possibility to estimate the quality and variance within a soil map. Diversity indices and abundance distribution models are statistical tools which ecologists have applied for decades for analyzing the intrinsic regularities of various ecological entities. In this study relationships between soils evolution, landscape and geomorphic surface and also pedodiversity index and pedodiversity index–area relationships were investigated in a part of Bam district in Kerman province were investigated. Pedodiversity index was computed at different taxonomy hierarchical levels (From order to family in Soil Taxonomy classification) and geomorphic hierarchical levels (landscape, landform, lithology and geomorphic surface) using appropriate indices including abundance, the Shannon diversity and O’ Neill index. Pedorichness (at family level)–area relationships were investigated to detect which model; power or logarithmic, better fits the observations of area. The results of study indicated that diversity indices such as Shannon and O'Neill indices of the level of classification hierarchy were increased because species richness has increased dramatically. Also diversity and richness indices with time from the old bajada to the younger bajada increased. That indicated taht the age of geomorphic surfaces affected soil development and soil diversity in the study area increased. Results also showed that pedorichness increases with the area of geomorphic surfaces. A logarithmic function gave a good fit for sample areas. Our results showed that increasing entropy versus time indicates the realm of divergent pathway of pedogenesis in studied region.