Vegetation changes in rangelands with abandoned coal-waste dumps during a 10-year period

Coal mining in rangelands accounts for a considerable amount of waste dumps that can be colonized by local plants over time. A thorough understanding of vegetation changes plays a key role in the management and restoration of such ecosystems.

This study aimed to assess the rangeland plant changes during 10 years on coal-waste dumps.

This study was carried out on three coal-waste dumps which were abandoned between 20 and 30 years in Karmozd mines in Savadkoh County, Mazandaran Province. Vegetation sampling was done in 2012 and 2022, estimating the cover percentage of all species in each 1 m2 plot. Species composition, functional groups, and species richness and diversity were compared between the two years.

Results showed changes in species composition and plant groups after 10 years. Some species were not found in 2022 while some new species were detected. The cover percentage of Bromus briziformis and Melica persica significantly increased but Hordeum vulgare was found to significantly decrease. The cover percentage of annuals and perennials significantly increased by 35.28% and 46.19%, respectively. Over the time, the cover percentage of grasses, forbs, and shrubs significantly increased. The results of ANOVA indicated a significant increase in species richness and diversity.

Vegetation changes during this period have not been affected by age of each dump since abandonment. Restoration treatments and plant species with phytoremediation potential are recommended to accelerate vegetation dynamics and reduce the consequences of coal-waste dump on the surrounding environment.