Mine rehabilitation is not just earthworks. Mine rehabilitation is a complex, integrated process that involves multiple stakeholders, long-term commitment, and a comprehensive understanding of site-specific conditions. When it comes to the re-introduction of vegetation, increasing the likelihood of successful plant establishment requires the proper implementation of many components including growth media movement, land forming, seedbed preparation, and seed delivery. From a perspective of initiating plant recruitment, best practice use of native seeds is fundamental, and seed technologies can also be coupled with the invention, development and modification of the seeding equipment needed to deliver seeds at scale. Improving seed-use efficiency through seed-enhancement technologies is one approach that has gained recent attention in dryland rehabilitation. Techniques including precision flash flaming, priming, polymer-based seed coating, and extruded seed pelleting all aim to improve the germination and establishment potential of seeds under suboptimal conditions. Along with modifications to existing mechanical seeders or with new builds, these technologies are one potential solution to overcome inefficiencies in dryland seeding efforts. For instance, through the fabrication and engineering of new parts fitted to existing seed-coating equipment, 'flash flaming' is a technique that removes unwanted hairs and appendages off bulky and fluffy seed batches (e.g. spinifex or Triodia species). After removal, seed batch volume is significantly reduced, while the flow properties of seeds through cleaning equipment and mechanised seeders are vastly improved.

The success of mine site rehabilitation using native seeds is hampered by poor seedling establishment. Seed enhancement treatments including seed coatings and pelleting form one strategy to improve establishment. However, for some seeds, particularly those of grasses, irregular shapes and surface features of covering floret structures are difficult to remove at commercial scales and these features hinder both the polymer seed coating process and the 'flowability' of material through mechanical sowing equipment. A flash flaming technique has recently been developed which effectively removes these surface features from Triodia (spinifex) florets. Tests show flaming imparts a significant volume reduction in seed collections, increases the bulk density, and improves the 'flowability' of treated florets, with little to no alteration to the viability of seeds. Current work is extending the application of flaming to additional genera with problematic features including those of Ptilotus, Cymbopogon, Eriachne, Stirlingia, Chloris, Rytidosperma, and Gomphrena. Different methods of flash flaming are being investigated to determine the optimum settings for each species to achieve a balance in 'flowability', seed survivability, and improvement in floret volume and bulk density. Future work is aimed at further improving the flash flaming method and testing the flow of treated seed material through commercial-scale seeding machinery.

Flash flaming has shown promise as a seed enhancement technology that improves the handling properties of bulky or irregularly shaped seed material, which in turn benefits logistical and ecological aspects of large-scale direct seeding. To date, only a small number of grass species, that possess similar morphological characteristics, have been tested. This paper describes the application of flash flaming to diaspores (i.e. the dispersal unit comprising the seed and any surrounding or attached tissues) of 19 diverse dryland species from the Amaranthaceae, Asteraceae, Chenopodiaceae and Poaceae critical to ecological restoration in the mining intensive Pilbara region of Western Australia. Flash flaming parameters for each species were tested to identify and maximise volume and mass reduction, reduce particle cohesiveness and maximise flow through a mechanical seeding device, whilst maximising germination. Flaming of all species resulted in reductions in batch volume and mass, and improvements to flow characteristics. For 17 species, flaming either benefited or did not impact on germinability. For two species in the Amaranthaceae, flaming with the settings tested here resulted in a reduction in germinability; however, flaming enabled the diaspores to pass through a mechanical seeding device enabling mechanical distribution which is critical if the species are to be used in large scale restoration.

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