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.

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Question Removal of vegetation and disturbance of the soil profile during mining reduce nutrient pools available for plants during mine site restoration. Thus, fertilizer is needed to replace the loss of nutrients available to support vegetation establishment. Yet the application of fertilizer can promote the establishment of competitively dominant species to the exclusion of others, particularly in low‐fertility ecosystems. Here, we test effects of fertilizer application rates on the establishment of jarrah forest. Location Five restored mine pits in the jarrah forest that grows on low‐fertility soils in southwest Western Australia. Methods Nitrogen (0 and 20 kg elemental N·ha−1) and phosphorus (0, 10, 20 and 40 kg elemental P·ha−1) were applied factorially to 20 m × 20 m field plots at five sites restored after bauxite mining with seeds and seedlings of jarrah forest species. Results Two and a half years after the experiment was established, there were no effects of N application rates on species richness, percentage vegetation cover or community composition of the restored jarrah forest. In contrast, P application had a number of effects on the restored jarrah forest. Species richness was highest at intermediate P application rates (10–20 kg·ha−1) and lowest at the two extreme treatments (0 and 40 kg·ha−1). Higher rates of P application resulted in a higher seedling density (2.5 vs 5.0 m−2 for 0 and 40 kg P·ha−1, respectively) and increased plant cover. Fertilizer P also significantly affected community composition, favouring ephemerals and weeds at high application rates and re‐sprouting species at lower application rates. Community composition was more similar to the restoration target (unmined jarrah forest) at 0 kg·P·ha−1 (similarity value of 36%) than at higher P application rates. Conclusions The data suggest that, in terms of maximizing species richness and percentage cover, a P application rate of between 10 kg·P·ha−1and 20 kg·P·ha−1is optimal for jarrah forest restoration after bauxite mining. Additionally, the data suggest no benefit of N application at a rate of 20 kg·N·ha−1.

An integral part of managing dust emissions from bauxite residue storage areas in Western Australia is the establishment of native vegetation and dust control crops. Recent changes to local health department regulations preclude the routine use of poultry manure, the previous standard fertilizer for growing dust control crops on bauxite residue sand. This paper reports on a field evaluation of different forms of inorganic fertilizer, to assess their effectiveness as alternatives to poultry manure for supplying nutrients to dust control crops. We compared plant growth and nutrient uptake under different forms of nitrogen (N) and phosphorus (P) fertilizers with additional potassium (K) and trace elements.A diammonium phosphate (DAP) based fertilizer blend which supplied 270 kg N ha −1 of N and 307.5 kg P ha −1 was found to be more effective than a superphosphate based blend containing the same amounts of these nutrients. The DAP treatment did not respond to topdressing with different N fertilizers, but plant growth in the superphosphate treatment was responsive to topdressing with N. Of the three different nitrogenous fertilizers evaluated for topdressing the superphosphate treatment (ammonium sulphate, diammonium phosphate, and urea), the ammonium based fertilizers were most effective. The DAP blend was the most cost effective of all the fertilizers studied, costing only A$1070 ha −1 compared with A$2473 ha −1 for the superphosphate blend and A$1600 ha −1 for poultry manure. We concluded that the DAP fertilizer blend could be used as an effective replacement for poultry manure for growing dust control crops on bauxite residue sand.

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