Reintroduction of native plants indicates the return of ecosystem services after iron mining at the Urucum Massif

Abstract

Abstract To reduce the net losses of biodiversity and ecosystem services caused by iron ore mining in Brazil, mineland rehabilitation using native plant species is necessary. However, systematic knowledge about which plant species are the best candidates for mineland rehabilitation is lacking. Therefore, iron mining companies working on the Urucum Massif reintroduce as many native herb and shrub species as possible to achieve the rehabilitation of savanna vegetation communities. To this end, seeds are collected from nearby native ecosystems, and seedlings are rescued from logged areas or produced in a local nursery. Monitoring is necessary to assess the persistence of the reinstated communities and their similarity to natural reference conditions. Ideally, monitoring efforts should compare the floristic composition of the rehabilitating sites with that of natural reference ecosystems. Here, we compared sites that had undergone two or three years of rehabilitation after iron ore mining on the Urucum Massif, MS, Brazil, with native reference sites. The species composition as well as structural, taxonomic, and phylogenetic diversity indices were compared between the reference and rehabilitating sites. Despite the differences in species composition between the rehabilitating and reference sites, we found more than 50 native species and partial recovery of the vegetation structure in the rehabilitating sites. Furthermore, we detected similar levels of animal‐dispersed plant species at rehabilitating and reference sites. These environmental indicators indicate that trial‐and‐error approaches are indeed able to establish considerable native species diversity during mineland rehabilitation. Furthermore, the partial recovery of the vegetation structure suggests the gradual return of soil functions in the long term, and the presence of zoochorous species is expected to attract seed‐dispersing animals that enable gene flow as well as the arrival of additional plant species. Nevertheless, the high cover values of alien exotic species, which are negatively correlated with the diversity of the reinstated communities, endanger the success of mineland rehabilitation in the Urucum Massif, and effective control methods for invasive populations are required. These efforts should be accompanied by enrichment plantings to maintain the diversity of native plant communities at the rehabilitation sites and ongoing environmental monitoring.

Keywords

• cangas
• environmental indicators
• environmental monitoring
• ferriferous savanna
• floristic composition
• invasive species