Stratification of Isfahan province regarding crop plants biodiversity during 2003-2012

Agricultural biodiversity is considered as one of the key factors determining the sustainability of agroecosystems. Preservation of biodiversity and its effective management have an important role in achieving economical, social and environmental measures of agroecosystem sustainability, hence it is essential that through precise evaluation of diversity trend in agricultural landscapes, while its preservation, effective steps also accomplish to proper management of diversity with considering the regional characteristics. Hence, current study was carried out with the aim of evaluation and analysis the changes in crop biodiversity of Isfahan province during 2003-2012 using ecological indices of diversity, including Margalef richness index, Evenness index and Shannon diversity index. Evaluation of variation trends of study indices showed that during 2003-2012 period, crop area, evenness index, Shannon index and beta diversity of Isfahan crops have significantly decreased. The downward trend of Isfahan province’s crop plants Shannon index indicated that during this period, the crop species biodiversity of Isfahan province has decreased. As, the Shannon index value of Isfahan crop species was decreased from about 2.30 in initial years of 2003-2012 period up to 2.15 in its terminal years. Results showed that significant decrease in evenness of crop area distribution and also significant reduction of crop area due to continues droughts and land use changes are among the main reasons for decline in crop diversity of Isfahan province during study period. According to cluster analysis, the townships of Isfahan province were also classified into six groups regarding their ten years average of Shannon diversity index.