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The forest floor of boreal forest stores large amounts of organic C that may react to a warming climate and increased N deposition. It is therefore crucial to assess the impact of these factors on the temperature sensitivity of this C pool to help predict future soil CO2 emissions from boreal forest soils to the atmosphere. In this study, soil warming (+2-4°C) and canopy N addition (CNA; +0.30-0.35 kg·N·ha-1·yr-1) were replicated along a topographic gradient (upper, back and lower slope) in a boreal forest in Quebec, Canada. After nine years of treatment, the forest floor was collected in each plot, and its organic C composition was characterized through solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Forest floor samples were incubated at four temperatures (16, 24, 32 and 40°C) and respiration rates (RR) measured to assess the temperature sensitivity of forest floor RR (Q10 = e10k) and basal RR (B). Both soil warming and CNA had no significant effect on forest floor chemistry (e.g., C, N, Ca and Mg content, amount of soil organic matter, pH, chemical functional groups). The NMR analyses did not show evidence of significant changes in the forest floor organic C quality. Nonetheless, a significant effect of soil warming on both the Q10 of RR and B was observed. On average, B was 72% lower and Q10 45% higher in the warmed, versus the control plots. This result implies that forest floor respiration will more strongly react to changes in soil temperature in a future warmer climate. CNA had no significant effect on the measured soil and respiration parameters, and no interaction effects with warming. In contrast, slope position had a significant effect on forest floor organic C quality. Upper slope plots had higher soil alkyl C:O-alkyl C ratios and lower B values than those in the lower slope, across all different treatments. This result likely resulted from a relative decrease in the labile C fraction in the upper slope, characterized by lower moisture levels. Our results point towards higher temperature sensitivity of RR under warmer conditions, accompanied by an overall down-regulation of RR at low temperatures (lower B). Since soil C quantity and quality were unaffected by the nine years of warming, the observed patterns could result from microbial adaptations to warming.

In the last two decades, partnership research has been rediscovered. The renewal of this interest is directly linked to a positive change of attitudes of researchers, in response to an increase of requests from practitioners for University conducted research and a change of priority in organizations providing research funds. In this article, we will examine this research model in the light of work done in the Réseau québécois de recherche partenariale en économie sociale (RQRP-ÉS). We recently have done an inquiry with practitioners who where partners in research done in the RQRP-ÉS. We present here the results from those interviews in terms of their motivations to work in the context of an academic process of producing new knowledge, the kind of participation they were involved in the research process and finally the conditions of success in conducting that kind of research.

L’article qui suit présente le cadre de réalisation des travaux de l’ARUC-ÉS. Cette section rappelle la genèse du programme de recherche, ses objectifs, le partenariat qu’il implique et la façon dont les travaux sont conduits. Nous concluons cette section en présentant les principales leçons qui se dégagent de notre expérience et les défis qui sont toujours à relever. Au nombre de ces défis, nous retrouvons la question liée à l’éternel débat sur la finalité de l’économie sociale et la place et la fonction qu’elle occupe eu égard à la transformation d’ensemble du système socioéconomique de la société québécoise. Nous développerons quelques éléments de réflexion sur cette question, ce qui nous permettra de présenter les trois éléments clés qui structureront les travaux de l’ARUC-ÉS au cours des cinq prochaines années.