International audienceHighlights(3-5 bullets max 85 char each) Abstract (should be 250 words) The current dominance of " ecosystem services " as a guiding concept for environmental management – where it appears as a neutral, obvious, taken-for-granted concept – hides the fact that there are choices implicit in its framing and in its application. In other words, it is a highly political concept.Following a political ecology framework, we investigate the origin and agency of the ecosystem services idea, its relationship to multi-scale power structures that constrain or facilitate certain outcomes, the practical difficulties of applying the idea, and its impacts for different parts of society and the environment.Building on the literature, on an analysis of theMillennium Ecosystem Assessment, and onbrief examples from tropical rain forest contexts such as Brazil and Madagascar, we investigate four moments or processes in the construction and application of the ecosystem services idea:discursive (the emergence of the term), ontological (what knowledge does the concept allow?), scientific (debates and difficulties in its practical application), and political (who wins, who loses?).All four components have ecological and political consequences. First, choices are made during the framing and institutionalization of the concept that mobilize, for example, a human-nature dichotomy and the pre-eminence of ecological and economic perspectives. Second, choices are made in the application of the concept, in terms of the type of service, the scale of analysis, and the kind of market rationality, that create winners and losers.The concept is a boundary object with widespread appeal, used in diverse ways by different interests to justify different kinds of interventions that at times might be totally opposed

Landscape dynamics result from forestry and farming practices, both of which are expected to have diverse impacts on ecosystem services (ES). In this study, we investigated this general statement for regulating and supporting services via an assessment of ecosystem functions: climate regulation via carbon sequestration in soil and plant biomass, water cycle and soil erosion regulation via water infiltration in soil, and support for primary production via soil chemical quality and water storage. We tested the hypothesis that patterns of land-cover composition and structure significantly alter ES metrics at two different scales. We surveyed 54 farms in two Amazonian regions of Brazil and Colombia and assessed land-cover composition and structure from remote sensing data (farm scale) from 1990 to 2007. Simple and well-established methods were used to characterize soil and vegetation from five points in each farm (plot scale). Most ES metrics were significantly correlated with land-use (plot scale) and land-cover (farm scale) classifications; however, spatial variability in inherent soil properties, alone or in interaction with land-use or land-cover changes, contributed greatly to variability in ES metrics. Carbon stock in above-ground plant biomass and water infiltration rate decreased from forest to pasture land covers, whereas soil chemical quality and plant-available water storage capacity increased. Land-cover classifications based on structure metrics explained significantly less ES metric variation than those based on composition metrics. Land-cover composition dynamics explained 45 % (P < 0.001) of ES metric variance, 15 % by itself and 30 % in interaction with inherent soil properties. This study describes how ES evolve with landscape changes, specifying the contribution of spatial variability in the physical environment and highlighting trade-offs and synergies among ES. (Résumé d'auteur

No abstract