Making differences legible: Incommensurability as a vehicle for sustainable landscape management

Landscape management involves tackling both systemic and social complexity: the former due to multiple interacting entities, the latter due to incommensurable knowledge and value systems of stakeholders. Current practice in landscape management makes wide use of participatory methods, which helps increase the breadth of our understanding of sustainability problems, e.g. biodiversity loss, agricultural pest damages or water penury. However, this practice also often offers a flat, harmonized picture of the landscape, which precludes observing ambiguities and out-of-the-box arguments and ideas for overcoming problems. In this article, we analyzed two research settings that tended to surface and formalize incommensurability between stakeholders regarding the sustainable management of landscapes - one focused on quantitative water management, the other on agroecological pest control. The objective was to investigate if and to which extent these 'opening-up' exercises, based on a deliberative rationale, were beneficial to landscape sustainability. The results indicated that in both cases, participants strove to position their knowledge and values relative to others: this way, they delineated a negotiation and learning space to invest in, and enhanced the quality of their arguments, allowing new insights on the focus issues. These findings offer an operational counterpoint to the prevalence of 'closing-down' approaches in landscape approaches. In the general context of ecological crisis, these examples promote methodological options that offer space to disruptive narratives, as well as tools that allow a reflexive use of the scientific knowledge, models and indicators traditionally used in sustainability appraisals, without discarding them.