Investigating the similarity between above ground vegetation and soil seed bank in order to evaluate the seed bank potential in improving the semi-steppe rangelands of ChaharMahal and Bakhtiari

Soil seed pool is an important source for plant diversity. Evaluating the soil seed bank condition and monitor its changes has high value for conservation, restoration, and management of rangeland ecosystems. This study aimed to investigate the similarity between above ground vegetation and soil seed bank in order to evaluate the possible potential of seed bank for recovering degraded vegetation communities in the semi-steppe rangelands in Karsanak located in Chaharmahal and Bakhtiari province. Three abandoned dry farming fields with different time laps after the last cultivation (3-5, 15-10 and >25 years) and an uncultivated site as control were selected. A systematic random sampling method was used to collect soil samples from two depths 0-5 and 5-10 cm of soil surface in 5 plots established along the transects in winter 2012 and transported to green house for seed germination test. Above ground vegetation of the plots was also studied in the next growth season. Indicator Species Analysis (ISA) was used to determine the indicator plant species in each succession stages. Detrended Corespondance Analaysis (DCA) was used for separating the species groups of the each succession stages. The results showed that the similarity between soil seed bank and above ground vegetation in the abandoned dry farming fields with 3-5 and >25 years after the last cultivation were 18.7% and 9.26% respectively. Results of DCA analysis and ISA analysis revealed that classification of plant communities on the basis of the above ground vegetation data set is more applicable than on the basis of soil seed bank. The majority of soil seed bank belong to the species of early stage of succession, hence soil seed bank is not an appropriate criteria for evaluating above ground vegetation in the abandoned dry farming fields.