Vegetation Succession After Bauxite Mining in Western Australia

Abstract

Alcoa World Alumina Australia has been rehabilitating bauxite mines in the jarrah forest of Western Australia for more than 35 years. An experiment was established in 1988 using three different seed treatments (legume and small understorey mix, small understorey mix only, and no seed) and two fertilizer treatments (N and P, and P only). The objectives of this study were to (1) document vegetation changes in the first 14 years after bauxite mining; (2) assess whether the vegetation is becoming more similar to the unmined forest; and (3) gain a better understanding of successional processes. Seed treatments significantly affected 13 of the 14 measured vegetation characteristics. Native species richness was higher in seeded than in unseeded sites at 1, 2, and 5 years of age, whereas diversity and evenness were generally higher at all assessment ages. Exotic species density was higher in unseeded than in seeded sites from 5 years onward, whereas richness was higher from 8 years onward. Nitrogen fertilizer significantly increased exotic species richness, density, and cover. Ephemerals dominated plant density in all rehabilitation treatments over time, whereas seeder species dominated cover. In contrast, resprouting species dominated density and cover in the unmined forest. Orchids were the only species that were not present in the first year in rehabilitated sites but increased in abundance over time. Vegetation composition in rehabilitated areas did not become more similar to the unmined forest during the 14 years since seeding, instead strongly reflected the initial species mix. Rehabilitated bauxite mines appear to follow the initial floristic composition model of succession.

Vegetation and Soil Properties Recovery, Biomass Accumulation after Limestone Quarry Restoration

“…A number of restoration success assessments have been conducted around the world evaluated the extents of native plants community re-establishment following quarry reclamation treatments. Some of the findings were indicative of successional shift of community in the direction of the pre-mining conditions [4], while other results were contrary to established ecological understanding. In south western Virginia for example, although the research by [5] recorded increases in pioneer native species in nurse-trees reclaimed coal mines, the study did not report a corresponding increase in intermediate and late succession trees or shrubs species in same area.…”

“…3) To evaluate and compare soil seed bank, soil depth and soil organic matter accumulation under the different nurse-plants. 4) To compare species richness and evenness between plots of different rehabilitation ages 2 -45 years after quarry restoration, irrespective of treatment type.…”

Dynamics of plant species during phytostabilisation of copper mine tailings and pyrite soils, Western Uganda

“…This was mainly due to the remarkable differences that still existed between the remediated soils and those at the undisturbed site. Failure to restore the original community on mine sites has been attributed by other authors to radical changes to almost every component of the landscape as well as persistent non-natural features [8,16,27,40,56]. The radical changes to the landscape and non-natural feature were still characteristic of the area under study.…”

Case Study: Some Lessons From the Early Development of Native Forest Rehabilitation at Three Surface Mine Complexes in Australia

“…In this context, proper assessments can only be a matter of extrapolation and speculation without longer term evidence incorporating species' life cycles and replacements. To this extent, as pointed out by Norman et al (2006) and , the currently used predictive criteria and short monitoring time frames are unlikely to be sufficient in the assessment of rehabilitation success.…”