Socioecological metabolism of livestock areas : an environmental accounting approach

The development of the livestock sector in the past century undergone a strong intensification. The current heterogeneity of livestock areas in France may have arisen from a spatial differentiation of intensification process. Different degrees of disconnection between livestock and land have resulted in contrasted levels of performance and impacts across areas. To date, a lot of research effort has been directed at measuring environmental impacts and economic performance of livestock systems at the farm level. Insufficient attention has been paid to the three dimensions of sustainability and to trade-offs among them. Existing livestock heterogeneities across areas also deserve more research. An approach that enables connecting livestock to land and resources, at regional level, could bring novel insights on the role of livestock in use and transformation of resources. The goal of this PhD was to develop a holistic assessment of livestock areas using multimetric indicators encompassing positive and negative contributions. We compiled three databases at the department level: i) database 1 was related to socioeconomic, land use, and production characteristics of 88 French departments, within an extensive time frame (1938-2010); ii) database 2 included data on crop, fodder and livestock production for year 2010; iii) database 3 included measures of provision of cultural, environmental and social services for 60 departments. With the first database, we created a typology of intensification trajectories based on a multivariate approach. With the second database, we assessed the nitrogen metabolism of livestock areas, based on the material flows accounting (MFA) approach, from which we derived indicators of performance and impacts to study synergies and trade-offs. With the third database, we studied the influence of past intensification on the current provision of services by the livestock sector. A multivariate approach was used to assess how different rates of change in intensification variables determined contrasted levels of services. First, we showed that the intensification of the French livestock sector was spatially differentiated and based on four trajectories, ranging from extensive to intensive livestock areas, and from crop specialized to areas where livestock had a small share of national production. Livestock productivity and stocking rates had a 3 fold increase in intensive areas, whereas extensive areas had a 1.6 fold increase. Crop specialized areas lose more than half of their original fodder area, and tripled the average farm size and more than quadrupled their labor productivity. Non-dominated livestock areas lose 30% of initial livestock population, and half of their initial fodder area. Second, the study of synergies and trade-offs revealed that gains in efficiency and economies of scale, often compromised other dimensions, e.g. through increased environmental impacts. The spatial analysis of relationship between performance and impacts revealed two types of synergies linked to the type of impact, either land or product-based. Both of which were in trade-off. Third, we showed that the provision of services was spatially structured and based on three types of service bundles, determined by different rates of change in intensification variables. Changes towards grazing systems resulted in higher provision of environmental and cultural services, whereas changes towards intensive systems resulted in higher levels of social services; but this was achieved at the cost of environmental services. This PhD thesis furthered the understanding on the temporal trajectories of livestock sector across areas in France. This knowledge could help to improve livestock sustainability. Our work provided knowledge on the drivers that shaped current intensification patterns and the provision of cultural, environmental and social services. It could be used to examine options for desirable longterm changes of the livestock sector.