Towards a multidimensional assessment grid of smallholders' oil palm plantations: a preliminary proposal from SPOP Project

International audienceThis contribution is an intermediate product of the ANR 1 research project, SPOP (Sustainable Palm Oil Production). SPOP project aims at providing scientific knowledge on the diverse oil palm cropping systems in Indonesia and Cameroon, and on their social, economic and environmental impacts. This knowledge should help identify best practices, adaptation strategies, and improvement needs towards sustainability. At this stage of the research programme, we first aimed to present the applied methodology and analyse its relevancy in light of the first field data collection

Assessing learning regimes leading to sustainable intensification at the farm level: a new perspective for management assistance for family farms

To help design advisory approaches tailored to farmers' needs, we propose to highlight the different learning processes that lead to more sustainable farms. To this end, we have defined the concept of 'learning regime' as the set of mechanisms that are triggers for and lead to the acquisition of new knowledge and skill s, allowing the head of the farm to improve his production and management methods. This concept has been tested in the cotton-growing basin of Bobo-Dioulasso in 30 farms considered innovative in five technical areas related to environmental sustainability. The results show that there are four different types of regimes (transformer-observer, reactive-networker, optimizer-self-reliant and imitator-dependent). These results call into question the assumption of homogeneity of farmers' capacities to change their routines to acquire new skills and know-how. However, give n that the nature of technical changes implemented is heavily influenced by the informational context in which the producer operates, supporting the learning of sustainability calls into question, in particular, the ability to empower farmers' vis-à-vis this context. While this work's contributions are currently mainly conceptual and methodological, it opens up new perspectives to improve processes and tools to support the emergence of a more sustainable agriculture

Review of the diversity of palm oil production systems in Indonesia: Case study of two provinces: Riau and Jambi

This paper proposes an overview of the development of oil palm production in Indonesia combining two levels: (i) a national and historical perspective of the development of the sector; (ii) a regional approach considering two contrasting provinces, Riau and Jambi. Starting with colonial times, the national approach deals first with the main periods that punctuate the development of oil palm plantations up to the contemporary period, marked by the liberalization of the economy. It emphasizes several factors that played a strategic role in the development of palm oil production, such as the role of the State and migration. After presenting the different models that structure the relationships among stakeholders and how these relationships have evolved, the role of small family planters is analyzed. This section ends with a review of some controversial issues: livelihood improvement, land tenure and customary rights, inclusion versus exclusion, market risks, forest and environmental threats and governance. The regional approach gives context to the development of palm oil production within two territories that have different historical backgrounds, with Jambi entering into production relatively recently. In each of the two provinces, the themes and issues involved in palm oil development identified at national level are analyzed, with specific emphasis on stakeholders� strategic behaviours. The paper concludes with a comparative perspective on both provinces

Functionalization of organic molecules by transition-metal-catalyzed C(sp3)-H activation.

International audienceTransition-metal-catalyzed C-H activation has recently emerged as a powerful tool for the functionalization of organic molecules. While many efforts have focused on the functionalization of arenes and heteroarenes by this strategy in the past two decades, much less research has been devoted to the activation of non-acidic C-H bonds of alkyl groups. This Minireview highlights recent work in this area, with a particular emphasis on synthetically useful methods

On the mechanism of the palladium-catalyzed β-arylation of ester enolates.

International audienceThe palladium-catalyzed β-arylation of ester enolates with aryl bromides was studied both experimentally and computationally. First, the effect of the ligand on the selectivity of the α/β-arylation reactions of ortho- and meta-fluorobromobenzene was described. Selective β-arylation was observed for the reaction of o-fluorobromobenzene with a range of biarylphosphine ligands, whereas α-arylation was predominantly observed with m-fluorobromobenzene for all ligands except DavePhos, which gave an approximate 1:1 mixture of α-/β-arylated products. Next, the effect of the substitution pattern of the aryl bromide reactant was studied with DavePhos as the ligand. We showed that electronic factors played a major role in the α/β-arylation selectivity, with electron-withdrawing substituents favoring β-arylation. Kinetic and deuterium-labeling experiments suggested that the rate-limiting step of β-arylation with DavePhos as the ligand was the palladium-enolate-to-homoenolate isomerization, which occurs by a βH-elimination, olefin-rotation, and olefin-insertion sequence. A dimeric oxidative-addition complex, which was shown to be catalytically competent, was isolated and structurally characterized. A common mechanism for α- and β-arylation was described by DFT calculations. With DavePhos as the ligand, the pathway leading to β-arylation was kinetically favored over the pathway leading to α-arylation, with the palladium-enolate-to-homoenolate isomerization being the rate-limiting step of the β-arylation pathway and the transition state for olefin insertion its highest point. The nature of the rate-limiting step changed with PCy(3) and PtBu(3) ligands, and with the latter, α-arylation became kinetically favored. The trend in selectivity observed experimentally with differently substituted aryl bromides agreed well with that observed from the calculations. The presence of electron-withdrawing groups on these bromides mainly affected the α-arylation pathway by disfavoring C-C reductive elimination. The higher activity of the ligands of the biaryldialkylphosphine ligands compared to their corresponding trialkylphosphines could be attributed to stabilizing interactions between the biaryl backbone of the ligands and the metal center, thereby preventing deactivation of the β-arylation pathway

Palladium-catalyzed β arylation of carboxylic esters.

International audienc

Do temperature and population size structure influence the quantity of fish eDNA in water?

International audienceVarious factors can influence the concentration of eDNA found in the environment and blur the link between eDNA results and in situ fish abundances, biomasses or even occurrences. We studied the influence of one abiotic factor, the temperature, and one biotic factor, the fish size class, on the amount of fish eDNA detectable in water. To do so, we conducted two controlled experiments using tench (Tinca tinca, L) placed into outdoor mesocosms during 1 week. The quantification of fish eDNA abundances was performed using quantitative PCR after filtrating a large volume of water (30 L). The Bayesian hierarchical ANOVAs performed on qPCR results did not detect the effect of size class on eDNA amount, but fish eDNA concentration was shown to increase significantly when temperature rose by 6 °C (no effect detected at 3 °C). This suggests that fish assemblage quantification of two thermally contrasting sites through eDNA is not directly comparable