Conservation-with-development landscapes, such as UNESCO's Man and Biosphere Reserves, differentiate between areas of "nature" and "society". In Paraguay's Mbaracayú Biosphere Reserve, as elsewhere, this model has been used to support governance that focuses on conservation in the "core area" and sustainable development in the "buffer zone". Such interventions are supported by evidence of biodiversity and threats to biodiversity. This paper challenges this divide by discussing other evidence relevant to governance: the social, political and economic influences that have shaped the Mbaracayú landscape. Accounting for this kind of evidence is likely to lead to greater appropriateness and acceptance of governance approaches.