Agricultural, forest and rural policy sectors' receptiveness to agroforestry intercropping systems in Quebec (Canada)

PosterIn Quebec (Canada), intercropping trees and crops is a new practice in the agricultural landscape dominated by conventional monocropping systems. As research goes on and slowly reveals the potential of these systems to address some key issues in agriculture, forestry and rural development, and as farmers’ awareness increases, there is a pressing need to find public support for these systems. In order to help the promoters of agroforestry intercropping systems in their search of support in the political arena, we conducted a comparative study of the receptiveness of the agricultural, forest and rural policy sectors to these systems. As the literature on public policy processes has stressed the importance of policy stakeholders’ ideas in the implementation of new policies, we used a conceptual framework based on cognitive schemes to compare the ideas driving these policy sectors with the ideas supporting agroforestry intercropping systems. Results based on the analysis of formal publications and semi-directed interviews conducted with agroforestry experts and policy stakeholders underline that agroforestry intercropping systems are mostly featured by their promoters as sustainable and multifunctional systems. The rural policy sector has proven to be the most receptive and the forest sector the less receptive, while the agricultural sector lies in-between, offering small-scale support to agroforestry intercropping systems. The analysis highlights that policy sectors integrating multifunctionality in their core ideas are supportive of agroforestry intercropping systems, while sectors remaining largely focused on specialization and productivity are less receptive. Our study also shows that public incentives might not be sufficient to drive the adoption of agroforestry intercropping systems since major barriers to their implementation remain in some policy sectors. Featuring these systems as productive might be a necessary argument shift to tear down policy barriers and increase public support

Budgeted Reinforcement Learning in Continuous State Space

A Budgeted Markov Decision Process (BMDP) is an extension of a Markov Decision Process to critical applications requiring safety constraints. It relies on a notion of risk implemented in the shape of a cost signal constrained to lie below an - adjustable - threshold. So far, BMDPs could only be solved in the case of finite state spaces with known dynamics. This work extends the state-of-the-art to continuous spaces environments and unknown dynamics. We show that the solution to a BMDP is a fixed point of a novel Budgeted Bellman Optimality operator. This observation allows us to introduce natural extensions of Deep Reinforcement Learning algorithms to address large-scale BMDPs. We validate our approach on two simulated applications: spoken dialogue and autonomous driving.Comment: N. Carrara and E. Leurent have equally contribute

Revégétalisation de sites miniers et valorisation de boues de stations d'épuration : cas de la Nouvelle-Calédonie

En Nouvelle-Calédonie, le développement économique est grandement lié à l’exploitation du nickel. Cette dernière possède en effet près du dixième des richesses mondiales. L’extraction intensive exercée au cours du 20è siècle a toutefois laissé des cicatrices importantes à travers le paysage et causé de nombreux dégâts environnementaux, notamment sur la faune et la flore des maquis miniers ainsi que sur la vie aquatique des rivières et lagons calédoniens. Afin de réparer ces torts, plusieurs efforts sont aujourd’hui réalisés par l’industrie minière et les collectivités. La réhabilitation des sites passant par leur revégétalisation, de nombreux essais de plantation ont été réalisés. Le rétablissement d’un couvert végétal sur sol minier se bute cependant à plusieurs difficultés liées principalement au faible pouvoir agronomique de ces sols. Afin de surmonter ces difficultés, l’apport d’un amendement organique constitue une solution particulièrement intéressante. Par ailleurs, la Nouvelle-Calédonie produit près 600 tonnes de biosolides/an qui, à défaut d’être valorisées, doivent être éliminées à grand coût dans les sites d’enfouissement. Alors que l’enfouissement des boues STEP comporte de nombreux inconvénients, leur valorisation comme amendement organique en restauration minière pourrait offrir des bénéfices considérables. L’objectif de l’essai consiste à démontrer l’intérêt de cette voie de valorisation ainsi qu’à réaliser une liste exhaustive des autres amendements et engrais organiques qui pourraient potentiellement être utilisés. Il vise également à fournir des recommandations sur l’encadrement de la revégétalisation, la fertilisation des sols miniers et sur l’application des biosolides. L’essai aura pu démontrer que des amendements au Code minier, notamment en ce qui concerne la réhabilitation de sites, sont nécessaires afin d’assurer une meilleure protection environnementale. Aussi, l’adoption de textes législatifs et règlementaires permettant d’encadrer l’application des boues STEP en restauration minière est une condition importante à la réussite de cette voie de valorisation. Finalement, l’essai aura permis de confirmer le potentiel intéressant des biosolides pour la revégétalisation, mais aussi que ces dernières devraient idéalement subir un traitement tel que le compostage et un apport en engrais organiques riches en phosphore et en calcium afin de mieux répondre aux besoins des sols latéritiques et des plantes ainsi que d’assurer la sécurité de la population

Promoting tree-based intercropping systems in the political arena : a cognitive analysis of public policies in agriculture, natural resources and rural development in Quebec

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.In Quebec, tree-based intercropping (TBI) systems are considered as potential contributors to climate change adaptation as well as ecological goods and services providers. TBI systems are consequently promoted by stakeholders as complex systems accurately addressing issues related to environmental deterioration, landscape degradation and rural devitalization. However, financing the implementation of these systems on farms remains a challenge. In fact, no clear policy on agroforestry or TBI systems has been developed and implemented yet in the province, complicating the work of both receptive farmers and experts. Thus, we could wonder how the arguments put forward by TBI systems promoters are or can be integrated at all in the mainstream ideas now driving three specific public policies (agriculture, natural resources and rural development). Our research uses qualitative methods and a content analysis based on Muller�s notion of referentials to understand how TBI systems can be integrated in the pre-existing referentials of actors in the agriculture, natural resources and rural development public policies. Based on the analysis of formal publications and semi-directed interviews, our preliminary results show that the referentials driving agriculture, natural resources and rural development policies are slowly shifting from strict economic development to multifunctionality and sustainable development. TBI systems may then have the opportunity to be integrated in these policies� referentials, especially when they are promoted as multifunctional and sustainable systems. Nonetheless, the integration of TBI systems is insufficient to produce large-scale policies given the present policies referentials, but may lead to small-scale initiatives support.Genevi�ve Laroche (1), Jean Mercier (2) and Alain Olivier (1) ; 1. D�partement de phytologie, Facult� des sciences de l'agriculture et de l'alimentation, Universit� Laval, Qu�bec, Canada. 2. D�partement de sciences politiques, Facult� des sciences humaines et sociales, Universit� Laval, Qu�bec, Canada.Includes bibliographical references

A Substrate-Independent Benthic Sampler (SIBS) for Hard and Mixed-Bottom Marine Habitats: A Proof-of-Concept Study

Sea cage fish farms are increasingly situated over hard and mixed substrate habitats for production and waste-dispersion reasons; yet in many cases, these installations are not being effectively managed with respect to benthic impacts due to the lack of a practical sampling method. This study presents the first set of results from a newly developed Substrate Independent Benthic Sampler (SIBS) device that captures the unconsolidated organic and inorganic matter that overlies almost all substrates. The contents of the samples were analyzed using extracted environmental DNA (eDNA) followed by metabarcoding of the bacterial 16S rRNA gene. SIBS microbial assemblages reliably changed with proximity to farm and concurred with visual assessments of impact. Moreover, the approach appeared to be very sensitive with respect to the enrichment gradient, being able to discern influences at distances of 500–1500 m from the impact source. Other spatial differences, due to region and farm, were small in comparison, and the effect of the underlying substrate type was minor. The samples contained sufficient previously described bacterial bioindicator taxa from enriched sediments, such that a meaningful biotic index could be calculated, thereby placing them on a well-established benthic enrichment spectrum with established environmental thresholds. SIBS-derived bacterial data provide a powerful new approach for mapping spatial boundaries of farm effects irrespective of substrate type and topography. More importantly, the tool should also permit quantitative assessment of benthic enrichment levels irrespective of substrate type from depths of at least 100 m. It therefore has the potential to solve the hard-bottom problem that has until now prohibited effective environmental monitoring at mixed and hard-bottom locations.publishedVersio

From sea surface to seafloor: A benthic allochthonous eDNA survey for the abyssal ocean

Environmental DNA (eDNA) metabarcoding could facilitate rapid and comprehensive biotic surveys in the deep ocean, yet many aspects of the sources and distribution of eDNA in the deep sea are still poorly understood. In order to examine the influence of the water column on benthic eDNA surveys in regions targeted for deep-sea polymetallic nodule mining, we investigated the occurrence of pelagic eDNA across: (1) two different deep-sea habitat types, abyssal plains and seamounts, (2) benthic sample types, including nodules, sediment, and seawater within the benthic boundary layer (BBL), and (3) sediment depth horizons (0–2 and 3–5 cm). Little difference was observed between seamounts and the adjacent abyssal plains in the proportion of legacy pelagic eDNA sampled in the benthos, despite >1,000 m depth difference for these habitats. In terms of both reads and amplicon sequence variants (ASVs), pelagic eDNA was minimal within sediment and nodule samples (<2%), and is unlikely to affect benthic surveys that monitor resident organisms at the deep seafloor. However, pelagic eDNA was substantial within the BBL (up to 13% ASVs, 86% reads), derived both from the high-biomass upper ocean as well as deep pelagic residents. While most pelagic metazoan eDNA found in sediments and on nodules could be sourced from the epipelagic, protist legacy eDNA sampled on these substrates appeared to originate across a range of depths in the water column. Some evidence of eDNA degradation across a vertical sediment profile was observed for protists, with higher diversity in the 0–2 cm layer and a significantly lower proportion of legacy pelagic eDNA in deeper sediments (3–5 cm). Study-wide, our estimated metazoan sampling coverage ranged from 40 to 74%, despite relatively large sample size. Future deep-sea eDNA surveys should examine oceanographic influences on eDNA transport and residence times, consider habitat heterogeneity at a range of spatial scales in the abyss, and aim to process large amounts of material per sample (with replication) in order to increase the sampling coverage in these diverse deep ocean communities.publishedVersio

Contexte politique québécois et pratique de l'agroforesterie : état des lieux.

Au Québec (Canada), il n’existe aucune politique globale encadrant la pratique de l’agroforesterie. Paradoxalement, les instruments de politiques publiques ayant un impact sur le déploiement des pratiques agroforestières à l’échelle du territoire sont nombreux. Enchâssés dans un environnement politique et règlementaire à la fois flou, complexe et changeant, ils sont souvent mal connus des forestiers, des agriculteurs et des intervenants qui les accompagnent. Cet article propose un état des lieux de l’influence des instruments de politiques publiques sur les haies brise-vent, les bandes riveraines arborées, les systèmes agrosylvicoles, les systèmes à arbres fruitiers et à noix, les systèmes sylvopastoraux et les cultures en boisé. L’étude exhaustive des politiques a permis de recenser neuf instruments appuyant directement ou indirectement l’implantation de ces systèmes, leur entretien et la récolte de leurs produits et six instruments limitant le déploiement de l’agroforesterie. L’analyse des conséquences de l’implantation d’arbres en champ et de cultures agricoles en boisé sur l’octroi des aides agricoles et forestières a pour sa part révélé que ces conséquences sont relativement mineures. Globalement, l’environnement politique et règlementaire s’avère mal adapté aux particularités des systèmes agroforestiers. Des ajustements aux programmes actuels paraissent nécessaires afin de rendre l’environnement politique plus favorable au développement de ces systèmes.In Quebec (Canada), there is no comprehensive policy governing the practice of agroforestry. Paradoxically, public policy instruments that impact on the deployment of agroforestry practices in the field are many. Embedded in a political and regulatory environment that is both vague, complex and changing, they are often poorly known to foresters, farmers and stakeholders. This paper offers an overview of the influence of public policy instruments on windbreaks, wooded buffer strips, agroforestry systems, fruit and nut tree systems, silvopastoral systems and crops under woody cover. The comprehensive policy review of has identified nine instruments that foster either directly or indirectly the implementation of these systems, their maintenance and harvesting of their products and six instruments limiting the deployment of agroforestry. The analysis of the consequences of introducing trees in a crop field and field crops in woodland on the provision of agricultural and forestry subsidies has revealed that these consequences are relatively minor. Overall, the political and regulatory environment proves unsuited to the particularities of agroforestry systems. Adjustments to current programs appear necessary in order to render the political environment more conducive to the development of these systems

SuspensionFeeding Benthic Species’ Physiological and Microbiome Response to Salmon Farming and Associated Environmental Changes

Caged salmon farming is increasingly undertaken in water bodies with strong hydrodynamics where hard and mixed substrate habitats are more prevalent. Yet, these structurally complex and heterogeneous habitats support diverse benthic communities including several cnidarians and sponges that remain poorly characterized. This study used a combination of respirometry measurements, gas chromatography and 16S rRNA metabarcoding to define the respiration rate, stable carbon (δ13C) and nitrogen isotopes (δ15N), fatty acid (FA) and microbial profiles, and assess the impact of salmon farming on four important epibenthic suspension-feeders along the western Norwegian coast: the sponges Craniella and Weberella, the soft coral Duva florida and the anemone Hormathia digitata. Our results showed striking differences in fatty acid profiles and host microbiome communities in terms of identity, functional capabilities and genetic properties across the suspension-feeders. We found evidence of increased mortality rate in specimens located near fish farm activities and of a species-specific effect on respiration rate, with D. florida showing increased activity under the farm. Effects of fish farming on the suspension feeders were also species-specific and particularly evidenced by functional microbial turnover and by alteration of overall FA profiles in the soft coral and sea anemone. In particular, D. florida showed reduced level of FAs close to the farm (0-350 m), with significant difference in composition along a distance gradient. Only H. digitata showed evidence of incorporation of organic material from the fish farm waste via fatty acids trophic markers (FATM) and stable isotope analysis. Overall, our study demonstrates that suspension feeders have taxon-specific sensitivity towards the effect of salmon farming, and identified several potential molecular indicators that could be used as surrogate of impact gradient upon further research and validation. It also provides a wealth of ecological and physiological information on some of the most common sessile epibenthic organisms within Arctic and sub-Arctic regions, enabling us to better understand their response and evaluate their resilience to environmental changes.publishedVersio

Effects of fish farm activities on the sponge Weberella bursa, and its associated microbiota

Sustained growth of world-wide sea farming and the search of optimal growing conditions have driven several countries, including Norway, to establish new finfish sites in more exposed, high current locations. Characterized by a range of gravel, broken rock and/or bedrock, these complex environments and the associated diverse range of epifauna species are not easily monitored via traditional methodologies (e.g. morpho-taxonomic identification and enumeration, and compound analyses of sediment grabs). Consequently, little is known about many of the benthic inhabitants, or how they may respond to fish farming. In this study, we aimed to initiate addressing this knowledge gap by assessing the response of the sponge Weberella bursa (Polymastidea) to salmon aquaculture. Fourteen specimens were translocated along a distance gradient from a salmon farm located along the mid-west coast of Norway. Following 7 months of exposure, their epithelial tissue were analysed for gene expression analysis (mRNA), fatty acid (FA), stable isotope and taxonomic and functional microbiome characterization. Among all datasets, only fatty acid profiles showed significant changes associated with fish farm activities, with higher proportion of terrestrial FAs and long saturated and monounsaturated FAs near the farm. These results suggest that W. bursa sponges may be more resistant to organic enrichment than previously thought. Nonetheless, several putative indicators of non-lethal response could be identified. Specifically, W. bursa specimens located underneath the farm tended to have reduced ribosomal activity while having increased expression of genes controlling cell apoptosis (e.g. caspase-3, cytochrome c oxidase and death domain proteins). Based on predictive functional analysis, specimens near to the farm were also found to be particularly enriched in sulfur and nitrogen cycling bacteria, and in microbial taxa with anti-toxin and xenobiotic biodegradation capability, notably of benzyl benzoate compounds used in sea lice treatments. These results indicate that potentially harmful elements such as sulfite, nitrite and pesticides may be neutralized and degraded by a particularly enriched set of bacteria in W. bursa microbiome. While additional research is needed to validate these putative indicators, our study provides a first glimpse as to how sessile organisms may respond and adapt to environmental changes induced by fin fish farming, and pave the way to the development of novel monitoring tools adapted to mix and hard bottom habitats.publishedVersio