Yunanto, T, Mitlohner, R & Bürger-Arndt, R 2019, 'Vegetation development and the condition of natural regeneration after coal mine reclamation in East Kalimantan, Indonesia', in AB Fourie & M Tibbett (eds), Mine Closure 2019: Proceedings of the 13th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1289-1302, https://doi.org/10.36487/ACG_rep/1915_102_Yunanto
(https://papers.acg.uwa.edu.au/p/1915_102_Yunanto/)
Abstract: As one of the most important mining commodities, coal has been massively exploited as a source of income for the national economy. In general, a coal mining company conducts mining operations in forest areas by employing an open pit mining method. The implementation of an open pit mining method can cause negative environmental impacts, i.e. changes to the forest landscape, reduction in soil quality, reduced biodiversity for both flora and fauna etc. To overcome and mitigate devastating environmental impacts resulting from mining operations in the forest area, land reclamation should be conducted on the ex-mine area. In Indonesia there is still little knowledge on vegetation development and the natural regeneration in mine reclamation areas. Therefore, it is important to understand the stand structure, floristic composition and whether or not the reclaimed mining area can create a good environment for natural regeneration and redevelop into a self-sustaining forest ecosystem. The research was carried out at six stand types, namely five differences age of reclamation areas and secondary natural forest for the comparison. A vegetation inventory was conducted at each stand type covering an area of ±1 ha (total ±6 ha) using a circular plot. Result shows that the stand structure (diameter at breast height, total height, density and basal area) between the reclamation areas were different. Moreover, the reclamation areas with an age greater than four years demonstrate higher mean values for different aspects of stand structure than the secondary natural forest. Conversely, in terms of floristic composition such as species and diversity index, secondary natural forest still had higher mean values than all ages reclamation areas. The older reclamation ages tend to have a higher number of species and diversity index than the younger ages. Natural regenerations were occurred from the first year of reclamation. In general, based on the regression analysis the number of naturally grown species in the seedling, sapling and tree stages tend to increase alongside the rise in reclamation age. These results conclude that the reclamation activities in ex-mine areas have succeeded to create favourable environmental conditions for natural regeneration.

Keywords: coal, mine reclamation, stand structure, floristic composition, natural regeneration