On diversity of human-nature relationships in environmental sciences and its implications for the management of ecological crisis.

Decision makers addressing the ecological crisis face the challenge of considering complex ecosystems in their socioeconomic decisions. Complementary to ecological sciences, other scientific frameworks, grouped under the umbrella term environmental sciences, offer decision makers the opportunity to pursue sustainable paths. Because the environmental sciences are drawn from different branches of science, environmental ethics must go beyond the legacy of ecology and the life sciences to describe the contribution of scientific knowledge to addressing the ecological crisis. In this regard, I analyze and compare three environmental sciences based on their seminal articles: Conservation Biology, Sustainability Science, and Sustainability Economics. My analysis shows that conservation biology and sustainability economics share strong similarities despite their different disciplinary backgrounds (life versus social sciences). Both seek to contrast a biocentric and an anthropocentric perspective. The goal of sustainability is therefore understood as a balance that must be found between these two perspectives. If the issue of balancing human and non-human interests is still relevant to sustainable science, it is more likely to take place in an ecocentric perspective based on alternative ontological and normative prescriptions. Based on this analysis, I distinguish between 'proscriptive value-based' scientific work that cannot be used for policy advice but is flexible to different value systems, and 'prescriptive value-based' scientific work that can be used for policy advice but is fixed within a given value system. Conflicting recommendations from environmental scientists therefore result from the coexistence of multiple 'prescriptive value-based' scientific approaches based on different conceptions of the relationship between humans and nature.

From population viability analysis to coviability of farmland biodiversity and agriculture.

Substantial declines in farmland biodiversity have been reported in Europe for several decades. Agricultural changes have been identified as a main driver of these declines. Although different agrienvironmental schemes have been implemented, their positive effect on biodiversity is relatively unknown. This raises the question as to how to reconcile farming production and biodiversity conservation to operationalize a sustainable and multifunctional agriculture. We devised a bioeconomic model and conducted an analysis based on coviability of farmland biodiversity and agriculture. The coviability approach extended population viability analyses by including bioeconomic risk. Our model coupled stochastic dynamics of both biodiversity and farming land-uses selected at the microlevel with public policies at the macrolevel on the basis of financial incentives (taxes or subsidies) for land uses. The coviability approach made it possible for us to evaluate bioeconomic risks of these public incentives through the probability of satisfying a mix of biodiversity and economic constraints over time. We calibrated the model and applied it to a community of 34 common birds in metropolitan France at the small agricultural regions scale. We identified different public policies and scenarios with tolerable (0-0%) agroecological risk and modeled their outcomes up to 2050. Budgetary, economic, and ecological (based on Farmland Bird Index) constraints were essential to understanding the set of viable public policies. Our results suggest that some combinations of taxes on cereals and subsidies on grasslands could be relevant to develop a multifunctional agriculture. Moreover, the flexibility and multicriteria viewpoint underlying the coviability approach may help in the implementation of adaptive management.

How does economic risk aversion affect biodiversity?

Significant decline of biodiversity in farmlands has been reported for several decades. To limit the negative impact of agriculture, many agro-environmental schemes have been implemented, but their effectiveness remains controversial. In this context, the study of economic drivers is helpful to understand the role played by farming on biodiversity. The present paper analyzes the impact of risk aversion on farmland biodiversity. Here "risk aversion" means a cautious behavior of farmers facing uncertainty. We develop a bio-economic model that articulates bird community dynamics and representative farmers selecting land uses within an uncertain macro-economic context. It is specialized and calibrated at a regional scale for France through national databases. The influence of risk aversion is assessed on ecological, agricultural, and economic outputs through projections at the 2050 horizon. A high enough risk aversion appears sufficient to both manage economic risk and promote ecological performance. This occurs through a diversification mechanism on regional land uses. However, economic calibration leads to a weak risk-aversion parameter, which is consistent with the current decline of farmland birds. Spatial disparities however suggest that public incentives could be necessary to reinforce the diversification and bio-economic effectiveness.