Rio Tinto commissioned the IUCN Economics Programme to assess the social costs and benefits of conserving Madagascar’s Tsitongambarika forest. The work started in 2009, and was completed following the signing of the IUCN-Rio Tinto agreement.

The largest expanse of lowland rainforest remaining in southern Madagascar, Tsitongambarika is being lost at a rate of 1-2% per annum due to shifting cultivation by poor communities. Rio Tinto has supported the conservation of 60,000 hectares of the forest, with particular focus on the 1,000 hectare Bemangidy forest.

These efforts go above and beyond the investments of QIT Madagascar Minerals (QMM) - which operates Rio Tinto's ilmenite mining operations in the Mandena, Petriky, and Sainte Luce littoral forests adjecent to (but at much lower elevation than) the Tsitongambarika humid forest - towards ensuring that their mining operations have a net positive impact on biodiversity.

The study quantified and valued changes in ecosystem services that would result from this conservation over “business as usual” (continued deforestation and ecosystem degradation). Ecosystem services examined included carbon storage, ecotourism, habitat conservation, and hydrological regulation.

The study found significant economic benefits associated with conservation, mainly linked to carbon storage values. However, these benefits appeared to be global (e.g., climate regulation, existence values for biodiversity) while the costs of conservation were borne predominantly by local communities. The study therefore pointed to the need for, and potential scale of, compensation of local populations, for example through Payments for Ecosystem Services.

The assessment was presented at the 10th Convention on Biological Diversity (CBD) Conference of the Parties (COP) in 2010 and published in 2011. The assessment was also used to road test the WBCSD Guide to Corporate Ecosystem Valuation published in 2011.

Rio Tinto is currently integrating the study methodology and results into its  biodiversity conservation efforts more generally, both in Madagascar and at an operational level.