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Mention de date : 2012
Paru le : 01/01/2012 |
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Ajouter le résultat dans votre panierPlant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review / Alain Ratnadass in Agronomy for sustainable Development, 32 (2012)
Titre : Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review Type de document : Imprimé Auteurs : Alain Ratnadass Année de publication : 2012 Article en page(s) : 273-303 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Diversité botanique
[CBNPMP-Thématique] Agroécologie
[CBNPMP-Thématique] Agroécologie et écologie forestière généraleRésumé : Farmers are facing serious plant protection issues and phytosanitary risks, in particular in the tropics. Such issues are food insecurity, lower income in traditional low-input agroecosystems, adverse effects of pesticide use on human health and on the environment in intensive systems and export restrictions due to strict regulations on quarantine pests and limits on pesticide residues. To provide more and better food to populations in both the southern and northern hemispheres in a sustainable manner, there is a need for a drastic reduction in pesticide use while keeping crop pest and disease damage under control. This can be achieved by breaking with industrial agriculture and using an agroecological approach, whose main pillar is the conservation or introduction of plant diversity in agroecosystems. Earlier literature suggest that increasing vegetational biodiversity in agroecosystems can reduce the impact of pests and diseases by the following mechanisms: (1) resource dilution and stimulo-deterrent diversion, (2) disruption of the spatial cycle, (3) disruption of the temporal cycle, (4) allelopathy effects, (5) general and specific soil suppressiveness, (6) crop physiological resistance, (7) conservation of natural enemies and facilitation of their action against aerial pests and (8) direct and indirect architectural/physical effects. Here we review the reported examples of such effects on a broad range of pathogens and pests, e.g. insects, mites, myriapods, nematodes, parasitic weeds, fungi, bacteria and viruses across different cropping systems. Our review confirms that it is not necessarily true that vegetational diversification reduces the incidence of pests and diseases. The ability of some pests and pathogens to use a wide range of plants as alternative hosts/reservoirs is the main limitation to the suppressive role of this strategy, but all other pathways identified for the control of pests and disease based on plant species diversity (PSD) also have certain limitations. Improving our understanding of the mechanisms involved should enable us to explain how, where and when exceptions to the above principle are likely to occur, with a view to developing sustainable agroecosystems based on enhanced ecological processes of pest and disease control by optimized vegetational diversification. Identifiant : DOI : 10.1007/s13593-011-0022-4 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=150285
in Agronomy for sustainable Development > 32 (2012) . - 273-303Ratnadass, Alain 2012 Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review. Agronomy for sustainable Development, 32: 273-303.Documents numériques
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Titre : Factors and processes affecting plant biodiversity in permanent grasslands. A review Type de document : Imprimé Auteurs : Etienne Gaujour ; Bernard Amiaud ; Catherine Mignolet ; Sylvain Plantureux Année de publication : 2012 Article en page(s) : 133-160 Langues : Anglais (eng) Résumé : Research has delivered convincing findings on the effect of biodiversity on ecosystem functioning and humankind. Indeed, ecosystems provide provisioning, regulating, supporting, and cultural services. The global value of annual ecosystem services of grasslands and rangelands is about US$ 232 ha−1 year−1 . Nevertheless, the precise evaluation of biodiversity benefits remains challenging. This issue is due to valuation methods, subjective assumptions, and complexity of drivers of plant community dynamics. Here, we review the primary factors that influence plant diversity of permanent grasslands, and we describe underlying processes. These factors must indeed be identified to focus policies meant to preserve and restore plant diversity and to advise farmers about efficient decision rules. We show that plant dynamics of permanent grasslands cannot be explained simply by agricultural management rules, e.g., grazing, fertilization, and mowing, implemented at the field scale. The configuration of the surrounding landscape, e.g., landscape heterogeneity, habitat fragmentation, and connectivity, acts as a species filter that defines the regional species pool and controls seed flow. The regional species pool often contains higher species richness in a heterogeneous landscape, because of a higher diversity of suitable habitats. This regional pool could be a major species sources for permanent grasslands according to the seed flow. We discuss the need to consider all of these factors to understand plant species composition of permanent grasslands and the necessity to study plant communities using both taxonomic and functional approaches. In order to report this integrative approach, we propose a conceptual model based on three ecological challenges— dispersal, establishment, and persistence—that are considered to act as filters on plant diversity, and a graphical representation of the complexity of such studies due to the interaction effects between plant dispersal abilities, forage productivity, disturbances induced by farming practices, and landscape heterogeneity on plant diversity. Last, we discuss the ability of farmers to manage each factor and the necessity of such study in the improvement of the current agro-environment schemes efficiency for farmland biodiversity restoration or preservation. Identifiant : DOI : 10.1007/s13593-011-0015-3 / HAL : hal-00930482
Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155389
in Agronomy for sustainable Development > 32 (2012) . - 133-160Gaujour, Etienne, Amiaud, Bernard, Mignolet, Catherine, Plantureux, Sylvain 2012 Factors and processes affecting plant biodiversity in permanent grasslands. A review. Agronomy for sustainable Development, 32: 133-160.Documents numériques
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Titre : A trait-based approach to comparative functional plant ecology: concepts, methods and applications for agroecology. A review Type de document : Imprimé Auteurs : Éric Garnier (1959-) ; Marie-Laure Navas Année de publication : 2012 Article en page(s) : 365-399 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Agroécologie
[CBNPMP-Thématique] BiodiversitéRésumé : Comparative functional ecology seeks to understand why and how ecological systems and their components operate differently across environments. Although traditionally used in (semi)-natural situations, its concepts and methods could certainly apply to address key issues in the large variety of agricultural systems encountered across the world. In this review, we present major advances in comparative plant functional ecology that were made possible over the last two decades by the rapid development of a trait-based approach to plant functioning and prospects to apply it in agricultural situations. The strength of this approach is that it enables us to assess the interactions between organisms and their environment simultaneously on a large number of species, a prerequisite to address questions relative to species distribution, community assembly and ecosystem functioning. The trait concept will be first defined, before presenting a conceptual framework to understand the effects of environmental factors on plant community structure and ecosystem properties via plant traits. We will then argue that leading dimensions of variation among species can be captured by some selected traits and show that a combination of three easily measured traits—specific leaf area (the ratio of leaf area to leaf dry mass), plant height and seed mass—enables us to assess how different species use their resources, interact with neighbours and disperse in time and space. The use of traits to address central questions in community ecology will be reviewed next. It will be shown that traits allow us to (1) understand how plant species are sorted according to the nature of environmental gradients, (2) evaluate the relative importance of habitat filtering and limiting similarity in the process of community assembly and (3) quantify two main components of community functional structure, namely, community-weighted means of traits and community functional divergence. The relative impacts of these two components on ecosystem properties will then be discussed in the case of several components of primary productivity, litter decomposition, soil water content and carbon sequestration. There is strong support for the biomass ratio hypothesis, which states that the extent to which the traits of a species affect those ecosystem properties depends on the abundance of this species in the community. Assessing the role of functional divergence among species on ecosystem properties will require major methodological breakthroughs, both in terms of metrics and statistical procedures to be used. In agricultural situations, we show that trait-based approaches have been successfully developed to assess the impacts of management practices on (1) the agronomic value of grasslands and (2) the functional composition and structure of crop weed communities and how these could affect the functioning of the crop. Applications in forestry are still poorly developed, especially in temperate regions where the number of species in managed forest remains relatively low. The last decades of research have led to the constitution of large data sets of plant traits, which remain poorly compatible and accessible. Recent advances in the field of ecoinformatics suggest that major progress could be achieved in this area by using improved metadata standards and advancing trait domain ontologies. Finally, concluding remarks, unanswered questions and directions for research using the functional approach to biodiversity made possible by the use of traits will be discussed in the contexts of ecological and agronomical systems. The latter indeed cover a wide range of environmental conditions and biological diversity, and the prospect for reducing environmental impacts in highly productive, lowdiversity systems will certainly imply improving our skills for the management of more diverse systems prone to a trait-based approach as reviewed here.
Identifiant : DOI : 10.1007/s13593-011-0036-y Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155390
in Agronomy for sustainable Development > 32 (2012) . - 365-399Garnier, Éric (1959-), Navas, Marie-Laure 2012 A trait-based approach to comparative functional plant ecology: concepts, methods and applications for agroecology. A review. Agronomy for sustainable Development, 32: 365-399.Documents numériques
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