Investigating Species Diversity of Family Brassicaceae along Khorramabad-Andimeshk Highway

To achieve sustainable development as well as the conservation of natural ecosystems and their biodiversity, it is necessary to study ecological foctors and their impacts on plant species diversity. The Khorramabad-Andimeshk highway was selected in the current study to investigate the diversity of the family Brassicaceae. The length of this highway is 100 km and its height ranged from 420 to 1740 m. The altitudinal range was divided into three classes. Sampling was performed separately at each of these classes in six time periods of one month interval. In each month, 300 plots (4 m2) were conducted with a distance interval of 5 km, based on the minimal area method. Data of each class were analyzed, using one-way analysis of variance (ANOVA) to determine the indices of species richness and diversity. A total of 46 species, belonging to 33 genera were identified. The majority of Brassicaceae species, across the study area, were annual plant species (41 species), showing the characteristic of arid and semi-arid environments. Results showed that elevation has no effect on species diversity but it has a significant effect on species richness. In addition, growth time has significant effects on species diversity and richness. The highest level of species richness was observed in the lower altitudes and the highest indices of species diversity and richness were recorded in March and May.