To evaluate reforestation in farms: a tool for smallholders and the sustainability of their initiatives (EvaRefo)

Despite consensus on the necessity to reforest agricultural landscapes for climate change mitigation and adaptation, the experiences of many small landholders in reforestation are tarnished by difficulties leading to disillusionment and abandonment of initiatives. After clarifying with stakeholders of reforestation efforts in Balalaica, a biological subcorredor in Costa Rica, it became clear that the sustainability of an initiative depends on clear objectives, and a series of corresponding factors and well-timed decisions. In response to these needs, we elaborated a simple evaluation tool, EvaRefo. On the basis of indicator development, EvaRefo accounts for the different dimensions of reforestation sustainability as perceived by small landholder reforestation initiatives (ecological, economic, social and cultural). It distinguishes the potential of a reforestation initiative (whether favorable conditions are gathered) and its performance (how well are the trees growing and fulfilling expectations). The tool makes the most of scientific and technical knowledge on reforestation conditions and processes, while remaining operationally simple so that small landholders can use it without specific investment nor high-level technical knowledge. The self-evaluation of initiatives facilitates learning and capacity-building directly from field experience. EvaRefo was applied to six types of reforestation initiatives, focusing on different primary objectives, to visualize the kinds of tradeoffs that are involved by focusing on one goal rather than another: timber production, water conservation, ecological conservation, rural and scientific tourism, agroforestry, and payments for environmental services. Consistently low scoring indicators corresponded to aspects of associative and technical capacities, self-sufficiency, and species suitability, revealing that the farmer involved in reforestation often finds himself isolated to successfully manage his reforestation initiative. (Résumé d'auteur

Non-CO2 greenhouse gas emissions from agriculture: analysing the room for manoeuvre for mitigation, in case of carbon pricing

Relationships between the greenhouse effect and agricultural activity are usually and firstly considered in terms of the impact of climate change on agriculture. But in reverse, farmers and herders may react to a climate policy imposing a carbon price to GHG-emitting activities, and possibly contribute to the emissions mitigation as well as to carbon sequestration. The degree of efficiency of the reactions will vary across regions of the world and across activities. A methodology considering risk associated with technology changes is proposed for estimating and accounting these reactions under production and resource constraints. For a business-as-usual scenario quantified by the integrated assessment model Image, decisions concerning land-use and alternative practices are modeled. Results indicate that main agricultural activities provide little room for manoeuvre for emissions mitigation.Environmental Economics and Policy,

Trade-offs among ecosystem services and productivity in coffee-based agroforestry systems in Nicaragua

Many studies have measured biodiversity loss across the coffee intensification gradient; some studies have shown, with contradictory results, the trade-offs between biodiversity loss and coffee production increments. Plot assessments of tree diversity, soil conservation, carbon sequestration and coffee production are lacking. We characterized the structure, productivity, diversity, soil conservation and carbon sequestration of 40 coffee agroforestry systems in two different areas in Northern Nicaragua. Coffee management, environmental conditions and soils properties were also characterized to better understand the trade-offs among services within the plots and their dependence on the local environment. These agroforestry systems were chosen to maximize contrasts in terms of biophysical context, botanical composition and management practices. Results (preliminary) showed significant differences in the vegetation structure that enabled us to identify main clusters: CAFS with dense and diverse overstorey canopy, CAFS with high Musa density and CAFS with low density of overstorey canopy. Changes in vegetation structure reflected differences in farmers' strategies but did not affect the overall coffee yield or the conservation of soils. Coffee yields had strong variations among the plots, and this was mainly related to the amount of fertilizer applied. Neither carbon sequestered, soil conserved nor tree diversity have a significant negative relationship with coffee productivity. However, coffee yields were low comparing with other coffee areas in the region. These results open new perspectives to improve coffee agroforestry systems' structural complexity and their relative ecosystem services without affecting their overall productivity. Further investigations and a more stratified sampling to get a good grasp of the whole range of variability (in highly productive areas with less shade canopy) are needed to fully understand the mechanisms involved in trade-offs

¿Por qué se invierte en plantaciones de Jatropha? Respuestas desde Costa Rica

Chapitre d'ouvrage qui sera traduit en portugais du Brésil et publié courant 2014International audienceIn a global context of incomplete information and controversies about the development of Jatropha curcas plantations for biofuel production, we analyze the case of Costa Rica where diverse actors have gotten involved in the promotion and the plantation of Jatropha, and abandoned it quite soon afterwards, without significant production. Trying to explain the renewed interest for Jatropha in spite of the observed disillusions, we identified a specific role for the plant in different strategies. We analyze that for reasons of competition between actors of research on Jatropha, there is little interest in systemizing and sharing knowledge about the plant and its potential for the production of energy. We conclude about the possible evolutions of the Jatropha situation according to alternatives for the different key actors of the plant development.En un contexto de información incompleta y de controversias al nivel mundial sobre el desarrollo de plantaciones de Jatropha curcas (Tempate) para biodiesel, analizamos el caso de Costa Rica donde actores diversos se involucraron en la promoción y plantación del cultivo y varios lo dejaron al poco tiempo por falta de producción significativa. Buscando explicación al interés renovado por la Jatropha, a pesar de las desilusiones observadas, identificamos un rol particular de la planta en estrategias muy distintas. Analizamos que por razones de competencia entre los actores de la investigación sobre Jatropha, no existe interés en sistematizar y compartir conocimiento sobre la planta y su potencial para la producción de energía. Concluimos sobre las evoluciones posibles de la situación de la Jatropha según las alternativas para los diferentes actores claves interesados en la planta

Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments

This publication provides a coherent treatment for the reactor neutrino flux uncertainties suppression, specially focussed on the latest $\theta_{13}$ measurement. The treatment starts with single detector in single reactor site, most relevant for all reactor experiments beyond $\theta_{13}$. We demonstrate there is no trivial error cancellation, thus the flux systematic error can remain dominant even after the adoption of multi-detector configurations. However, three mechanisms for flux error suppression have been identified and calculated in the context of Double Chooz, Daya Bay and RENO sites. Our analysis computes the error {\it suppression fraction} using simplified scenarios to maximise relative comparison among experiments. We have validated the only mechanism exploited so far by experiments to improve the precision of the published $\theta_{13}$. The other two newly identified mechanisms could lead to total error flux cancellation under specific conditions and are expected to have major implications on the global $\theta_{13}$ knowledge today. First, Double Chooz, in its final configuration, is the only experiment benefiting from a negligible reactor flux error due to a $\sim$90\% geometrical suppression. Second, Daya Bay and RENO could benefit from their partial geometrical cancellation, yielding a potential $\sim$50\% error suppression, thus significantly improving the global $\theta_{13}$ precision today. And third, we illustrate the rationale behind further error suppression upon the exploitation of the inter-reactor error correlations, so far neglected. So, our publication is a key step forward in the context of high precision neutrino reactor experiments providing insight on the suppression of their intrinsic flux error uncertainty, thus affecting past and current experimental results, as well as the design of future experiments

Guía metodologica PARDI - Problematica - Actores - Recursos - Dinamicas - Interacciones: Para el análisis de las dinámicas socio-ecológicas

This short guide presents and details the different steps for the participatory construction of a conceptual model that serves the analysis of local socio-ecological dynamics focusing on an issue of natural resource management. This methodological note in spanish compiles different documents and presentations on the ARDI method, participatory modelling and the analysis of socio-ecological dynamics, by Christophe Le Page, Michel Etienne, Jérôme Queste, Guy Trébuil, Julio César Salinas, and Jean-François Le Coq.La guía presenta y detalla brevemente los diferentes pasos para la construcción participativa de un modelo conceptual que facilita el análisis de las dinámicas socio ecológicas a partir de una problemática de manejo de recursos naturales. Esta nota metodológica en español es una compilación de diferentes documentos y cursos sobre el método ARDI, la modelación participativa y el análisis de las dinámicas socio-ecológicas, por Christophe Le Page, Michel Etienne, Jérôme Queste, Guy Trébuil, Julio César Salinas, and Jean-François Le Coq