Relationships between Soil Properties and Plant Species Diversity in Natural and Disturbed Ecosystems (Case Study: Jamilabad Region, Kerman Province, Iran)

Abstract

Abstract. Reduction of species diversity which is a significant threat to the earth has been
found more important and has attracted attention among ecologists over recent years. This
research was carried out to determine the relationships between plant species diversity
indices and soil properties by multivariate regression methods in Jamilabad region, Baft,
Kerman province, Iran in 2016. Different sites of natural ecosystem (including non-grazed,
moderate grazed and over-grazed rangeland) and disturbed ecosystem [including
rangelands plowed to Glycyrrhiza glabra root harvesting and abandoned dry land for ten
years (Fallow) sites] were selected by fieldwork with the same climate, topography and
geological factors. Abundance and canopy of species and soil samples (0-20 cm) were
taken from each site contemporary for multivariate regression model and its validation.
Determination of species diversity indices was done by PAST and BIO-DAP packages.
Results revealed that regression models had higher accuracy in the disturbed ecosystem. In
this regard, soil erodibility factor as well as soil total nitrogen explained 80% and 77%
total variation in both Shannon-Wiener and Margarof indices, respectively. Results showed
that even though the soil erodibility was excluded from the model, its components such as
organic matter (in Berger-Parker index) had an important role in plant diversity. Therefore,
soil erodibility or its components were strongly affected by plowing in the disturbed
ecosystem and led to the formation of strong regression models between soil properties and
species diversity indices.