Guillen, G 2011, 'Progressive reclamation in a tropical rainforest – French Guiana', in AB Fourie, M Tibbett & A Beersing (eds), Proceedings of the Sixth International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 239-243, https://doi.org/10.36487/ACG_rep/1152_26_Guillen
Reclaiming impacted mining areas in a rainforest is a challenging endeavour. There are two commonly held and conflicting beliefs around this subject: the first is that reclamation in tropical zones is not necessary as disturbed areas quickly revegetate on their own. The second commonly held idea is that disturbed jungle sites cannot be properly rehabilitated, due to poor soil conditions. The case presented in the paper refutes both of these ideas and illustrates how with little money and the right species, successful reclamation is possible, even in the most challenging conditions.
There are few examples of reclamation projects in French Guiana, let alone successful ones. Facing the need to establish a reclamation strategy for its proposed project Camp Caïman in French Guiana, IAMGOLD Corporation created its own pilot project to establish the baseline information for its reclamation approach. The company chose an exploration site where mining operations had ceased 15 years prior. Similar to other sites, top soil have been removed and/or eroded and little natural succession of the surrounding rainforest had occurred.
Undertaken between 2008 and 2009, the project was designed to document the rehabilitation progress from start to finish. The first step for successful reclamation is to regenerate microbiologial activity in the soil by planting pioneer, nitrogen-fixing species. These grow quickly and provide shade and debris that favour local species. The operation’s success depends on the diversity of species that could be planted and would survive, ultimately allowing a gradual recolonisation by animals. The key to success was finding the right mix of pioneer species that were both nitrogen fixing and non-invasive.
More than two years after the plantation was established, success was confirmed by strong plant growth. The site enables thriving plantation of 5 ha, with the use of cuttings from pioneer species, seeds and plants from the IAMGOLD tree nursery, and, without addition of top soil. With a ratio of 2,000 plants and 100 different species per hectare, the project became an example of best practice for encouraging biodiversity in former mining sites and has been visited by many stakeholders in French Guiana.