Dobrowolski, MP 2022, 'Flora Restorer: sowing a diverse ecosystem', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: 15th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 989-998, https://doi.org/10.36487/ACG_repo/2215_72
Seed for restoring natural ecosystems is an expensive and finite resource. Yet seedling emergence is notoriously low in mining rehabilitation and restoration projects more generally. Unlocking this potential in broadcast seed has been critical to restoring a diverse kwongan ecosystem at Iluka’s Eneabba mineral sands mine, in the mid-west of Western Australia.
Using an innovative combination of rehabilitation practices in the sandy soils of Eneabba—seed burial, land imprinting, and an artificial soil crust—two-fold more seedlings emerged from broadcast seed in 2017 than from standard rehabilitation practice of ripping and seed broadcast. To combine and automate these practices in a single pass, we designed, built, and commissioned tractor-drawn equipment named ‘Flora Restorer’. Flora Restorer spreads fertiliser, scarifies the uneven soil, air-seeds a diverse size and shape seed mix, land imprints and thereby buries the seed, and sprays the soil surface with dilute bitumen emulsion forming an artificial soil crust to stop wind and water erosion.
Over the last four years of use, consistently two- to three-fold more seedlings have emerged from broadcast seed using Flora Restorer than from previous rehabilitation practice. Independently, long-term botanical monitoring has also demonstrated revegetation improvement using Flora Restorer, with species richness more than 50% higher and native plant cover more than double compared to rehabilitation at Eneabba over the previous 20 years. Flora Restorer demonstrates that large improvements in revegetation outcomes are possible in mining rehabilitation by automating seed sowing in combination with land imprinting and application of an artificial soil crust.
Keywords: mining rehabilitation, revegetation, ecosystem restoration
Bell, DT, Carter, DJ & Hetherington, RE 1986, ‘Experimental assessment of wind erosion after soil stabilization treatments at Eneabba, Western Australia’, Environmental Geochemistry and Health, vol. 8, pp. 99–104.
Bellairs, SM & Bell, DT 1993, ‘Seed stores for restoration of species-rich shrubland vegetation following mining in Western Australia’, Restoration Ecology, vol. 1, pp. 231–240.
Dixon, RM 1995, ‘Water infiltration control at the soil surface: Theory and practice’, Journal of Soil and Water Conservation, vol. 50, no. 5, p. 450.
Dobrowolski, MP 2019, ‘Combining seed burial, land imprinting and an artificial soil crust dramatically increases the emergence of broadcast seed’, in AB Fourie & M Tibbett (eds), Mine Closure 2019: Proceedings of the 13th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 667–678,
Engeman, RM, Nielson, RM & Sugihara, RT 2005, ‘Evaluation of optimized variable area transect sampling using totally enumerated field data sets’, Environmetrics, vol. 116, pp. 767–772.
Lamichhane, JR, Debaeke, P, Steinberg, C, You, MP, Barbetti, MJ & Aubertot, J-N 2018, ‘Abiotic and biotic factors affecting crop seed germination and seedling emergence: a conceptual framework’, Plant and Soil, vol. 432, pp. 1–28.
R Core Team 2013, R: A language and environment for statistical computing, R Foundation for Statistical Computing, Vienna,
van der Westhuizen, C, Rintoul, L & Baumgartl, T 2011, ‘Mined sand dune rehabilitation success on North Stradbroke Island – a study of the origin and effects of hydrophobicity’, Proceedings of the Royal Society of Queensland, vol. 117, pp. 365–376.
Wilcox, R 2012, Introduction to Robust Estimation & Hypothesis Testing, 3rd edn, Elsevier, Amsterdam.