Дисертації з теми "Diversité agricole"
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Andrieu, Nadine. "Diversité du territoire de l'exploitation d'élevage et sensibilité du système fourrager aux aléas climatiques : étude empirique et modélisation." Paris, Institut national d'agronomie de Paris Grignon, 2004. http://www.theses.fr/2004INAP0027.
Повний текст джерелаMaizeray, Lidwine. "La gestion de la diversité mise à l'épreuve : le cas du groupe Crédit Agricole SA." Thesis, Paris 2, 2014. http://www.theses.fr/2014PA020057/document.
Повний текст джерелаThe institutional pressure of laws and associations, as well as the search for economic performance, combined with various expectations, create a gap of perception between the idea of an ideal policy and the reality of diversity felt by the actors within their organisation.This gap leads to forms of demotivation and demobilisation, unfavourable to the development of a diversity policy which would claim to be efficient. How could we actually limit the unavoidable slowdown of the diversity management? Once the reasons why the actors of an organisation such as Crédit Agricole S.A. are restrained in developing an inclusive type of diversity management are analysed, this thesis brings tangible solutions to manage diversity in a way which is closer from the actors’ expectations.From a triangulation of data analysis within the framework of a qualitative methodology,inclusion has not necessarily appeared as the actors’ main expectation. Participative observation, the main case study highlighted with 3 complementary cases, 55 interviews (15 about diversity + 40 related to the handicap dimension), allow thus to bring managerial propositions to meet the main expectation of the actors which is the need to dialogue, in the sense of talk. The first step involves identifying the actors likely to be demotivated in order to mobilize them by allowing them to speak again afterwards. Allow them to speak does not necessarily involves setting up formal procedures, but more precisely taking time to exchange, creating a sharing time and thus establishing a better quality of life at the workplace
Dembele, Sidi. "Structuration spatiale de la biodiversité agricole dans la zone cotonnière du Mali." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC046.
Повний текст джерелаThe diversity of cropping systems and varieties plays an important role in the ability of family farms to withstand socio-economic and environmental shocks. For better conservation, this agricultural diversity needs to be characterized and monitored in space and time. While they were dominated by elements of price, area and production until recently, agricultural monitoring systems are beginning to integrate diversity issues. The diversity of cropping systems and varieties plays an important role in the ability of family farms to resist socio-economic and environmental shocks, whereas until the end of the 1990s it was considered as a limiting factor in improving the productivity of farming systems in varietal selection processes. In a situation of uncertain rainfall, to reduce the risk of this hazard, farmers use several species and varieties to survive and produce through all the hazards encountered. The peasant strategy consists in cultivating several varieties with different agronomic characteristics (early maturity, yield, resistance to diseases, parasites and drought, etc.) and culinary in the same field or in different fields. This strategy allows farmers to cultivate the varieties best suited to the soil conditions of their fields and to meet their diverse needs.It is in this context that this thesis focuses on the spatial structuring of agrobiodiversity in the cotton zone. To achieve this objective, several methods and approaches have been used. The approach adopted combines the digital analysis of satellite imagery and the use of data from field surveys. The analysis of these data is based on the spatial distribution of biodiversity and its correlation with agro-ecological practices and conditions, agronomic performance and performance.The main results from the analysis of the study data are:a) There is a great heterogeneity and diversity of landscapes in the cotton zone of Mali-Sud with a total of eleven (11) landscape units;b) There is great diversity at the specific level and in cropping systems. The mean values of the most specific indicator of diversity are recorded in villages where the mean rainfall is between 700 and 1000 mm of water followed by villages of less than 700 mm;c) The specific pressure indicator shows a geographical distribution of the pressures of the different crop species. Indeed, in villages where cotton is at the head of rotation, it exerts strong pressure on other species. In these villages, the cotton area is much larger than for the other species;d) For yield, most villages have average yields of cotton above the national average in 2015. Analyzing its evolution between 2013 and 2015, there is a decline in yield in most villages if this decline is very often sawtooth with increases in 2013 and 2014.e) The yield stability indicator shows that yields are stable with all species except maize.These results open the way for a greater contribution of geography in agronomic analysis
Jamin, Jean-Yves. "De la norme à la diversité : L'intensification rizicole face à la diversité paysanne dans les périmètres irrigués de l'Office du Niger (Mali)." Phd thesis, Institut national agronomique paris-grignon - INA P-G, 1994. http://tel.archives-ouvertes.fr/tel-00408411.
Повний текст джерелаCette diversité des réponses nous a conduit à nous interroger sur la diversité des fonctionnements des exploitations agricoles. Celle-ci a été analysée dans une démarche "systèmes de production" prenant en compte aussi bien le riz que les activités non-rizicoles, mais aussi dans une démarche de "recherche-développement" associant étroitement les cadres du développement aux travaux entrepris.
La typologie élaborée met en évidence l'importance des composantes non rizicoles des systèmes de production dans le fonctionnement global de ceux-ci, mais aussi la sensibilité des exploitations de l'Office du Niger aux aléas extérieurs. Les suivis de parcelles effectués montrent que cette diversité des fonctionnements a des conséquences sur la conduite des rizières, puisque l'on retrouve à ce niveau une assez forte variabilité des pratiques culturales. A partir de là, des recherches plus techniques ont été entreprises pour répondre aux problèmes identifiés, avec le souci d'élaborer des références susceptibles de valoriser la diversité des exploitations agricoles et utilisables facilement par des conseillers agricoles.
La typologie n'est pas restée un outil de description de la réalité, elle a pu être utilisée pour définir des actions prenant en compte la diversité des exploitations. Pour les recherches techniques, elle a conduit à mettre l'accent sur la mise au point de modèles d'intensification différenciés, plus souples. Pour le conseil technique rizicole, elle a permis de moduler les conseils en fonction des objectifs et des contraintes des différents types d'exploitations. Elle a aussi permis, en montrant l'importance des activités non-rizicoles dans le fonctionnement de certains types d'exploitations, de développer un conseil sur le maraîchage et l'élevage, auparavant négligés. Enfin, elle fournit aux décideurs politiques et financiers des éléments sur les mesures à prendre en matière de réhabilitation des casiers, de réattribution foncière, d'aménagement de l'espace, d'intégration sociale et d'organisation des producteurs.
Motte-Bienabe, Estelle. "Les politiques de conservation de la diversité biologique : évaluations, critères de décision et incitations." Montpellier 1, 2000. http://www.theses.fr/2000MON10071.
Повний текст джерелаBarnaud, Adeline. "Savoirs, pratiques et dynamiques de la diversité génétique : le sorgho (Sorghum bicolor ssp. bicolor) chez les Duupa du nord Cameroun." Montpellier 2, 2007. http://www.theses.fr/2007MON20103.
Повний текст джерелаMauchamp, Leslie. "Biodiversité et gestion des écosystèmes prairiaux en Franche-Comté." Thesis, Besançon, 2014. http://www.theses.fr/2014BESA2036/document.
Повний текст джерелаGrassland ecosystems are submitted to human pressure, especially due to agricultural management, preventing their natural succession toward the forest. However, when this pressure become too important, it could lead to a decrease of the diversity of plant communities (especially primary and secondary consumers) and of all communities that depend on them. As biodiversity is recognized to play an important role in the realization of ecosystem functions and services that benefit to human societies every day, important anthropic pressures could alter the maintaining of these services.In order to provide complementary information on the response of plant communities to anthropogenic factors, it is necessary to take into account the complexity of biodiversity, especially by including the various taxonomic, phylogenetic and functional facets of diversity. In addition, the spatial scale has to be taken into account, by comparing alpha (intra-site), beta (inter-site) components of the gamma diversity of a given parcel or region:.In this project, we especially focused on the complementarity of these approaches to diversity in order to assess the response of plant communities of the French Jura Mountains to agricultural practices used in this area. The production of PDO cheese, and especially the Comté cheese, offers an original framework for such investigations as the existence of this production is associated to strict regulations imposed to farmers for the management of their grassland systems. We studied the vegetation of 48 grasslands, split according to an altitudinal gradient (First Plateau, Second Plateau, High Range) by using an original multi-scale sampling design with plot sizes of 0.01, 1, 10 and 1000 m². The agricultural practices used on these 48 parcels have also been recorded by submitting questionnaires to farmers. In addition, we collected data on soil conditions in each parcel, including soil depth and physico-chemical analyses performed on 0 – 10 cm superficial soil samples.[...]The comparison of the species composition of 150 phytosociological relevés recorded in the 1990’s and repeated in 2012 reveals important changes in the floristic composition of grasslands. The general trend observed for the overall set of relevé suggests that contemporary communities are more adapted to frequent and/or intense defoliations, have a higher pastoral value and indicate a higher level of nutrient content in the soil. We also record differences in phylogenetic diversity values between the two sessions of relevés (while the taxonomic diversity of Simpson do not change) and so show that a loss of phylogenetic lineages among time.[...]The accumulation of phosphorous in the soil, associated to increasing nitrogen supply, especially in the form of inorganic fertilizers, can partly explain this trend. Even though we do not record any significant reduction of taxonomic diversity, the functional changes already observed suggest that the diversity could potentially decrease in the future.[...]
Lorel, Claire. "Concilier le développement urbain et agricole avec la conservation de la biodiversité : anticipation de l'empreinte des activités anthropiques sur la biodiversité par une approche fonctionnelle et multi-trophique." Thesis, Paris, Muséum national d'histoire naturelle, 2018. http://www.theses.fr/2018MNHN0009/document.
Повний текст джерелаThe strong growth of Human populations has led to the intensification of land uses and land covers, especially in agricultural lands for food production and livestock, resulting in a higher appropriation of net primary productivity. As primary productivity is the root of food webs and ecological networks, any change in this essential process is likely to have a strong impact on biodiversity. Besides, intensification is a complex process whose three dimensions - inputs, outputs and system - are rarely studied together. The conceptual and methodological framework of HANPP (Human Appropriation of Net Primary Production) proposed by Helmut Haberl and collaborators in 2007, aims to quantify different parameters of intensification. First, I explored the variability of HANPP components and their relationships to other intensification indices (i.e. HNV, IC / ha) to better interpret the variability of HANPP and its components. HANPP seems to be linked to both the "system" and "output" dimensions of land use intensity and appears to complement the other indicators considered. Then, I investigated the relationship between HANPP and biodiversity, focusing on two taxa complementary in their ecosystem functions, i.e. birds and bats. Using data from citizen-science programs occurring in metropolitan France, I showed that intensification: i) decreased species richness, abundance and the average mass of bats, and ii) simplified the structure of avian communities by lowering the average trophic level and functional regularity, to the benefit of farmland specialists. In addition, I observed that the response of biodiversity could widely vary depending on the indicator and / or facet (taxonomic or functional) studied. Through my analyzes, I was able to clarify the conditions of use of the HANPP methodological framework. I also identified areas and types of landscape where land use intensity can coexist with biodiversity. All of these results form the basis for a discussion on opportunities to reconcile conservation efforts with intensification
Sauget, Nicole. "Agro-écosystème et société : la diversité des façons de produire des agriculteurs dans les coteaux de Gascogne." Paris 10, 1996. http://www.theses.fr/1996PA100005.
Повний текст джерелаVillemey, Anne. "Trame verte et papillons de jour en contexte agricole : influence du paysage sur la dispersion, la diversité génétique et la composition des communautés." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2052/document.
Повний текст джерелаThe implementation of the “Green and Blue Infrastructure” in France intends to ensure the functional connectivity of habitats (green veining). It is one of the nature conservation policies which aim to reduce the loss of biodiversity caused by the destruction and degradation of natural habitats. The objective of this work was to quantify the impact of connectivity, in comparison to other environmental factors, on the diversity of butterfly communities and their genetic diversity in three French agricultural regions. Two different approaches were applied to understand the underlying processes driving these diversity patterns: i) the study of the whole community and of the different ecological groups, ii) the study of landscape features resistances to butterfly dispersal using a landscape genetics approach on one species: the Meadow brown (Maniola jurtina L.). Our findings show that although local characteristics play a dominant role, landscape context does have an influence on community composition. Arable land cover decreases species diversity, and the Meadow brown genetic diversity and gene flow. Grasslands support more species rich communities, including non-frequent species. Grassy linear landscape elements host impoverished communities, but improve Meadow brown dispersal and enhance its genetic diversity. Species diversity is higher within grasslands in proximity to woody habitats: butterflies may benefit from resources on forest edges; moreover, woodlands seem to limit Meadow brown dispersal while increasing its genetic diversity. The habitat complementarity we evidenced here led us to question the classic model of ecological continuities as a collection of independent sub-networks, one for each type of habitat. According to conservation issues, species under interest and landscape contexts, we also need to identify situations where, among a broad panel of possible conservation actions, increasing connectivity is the most effective solution
Manusset, Sandrine. "La question des abattis dans le bas Oyapock (Guyane française) : pérennité et diversité d'une pratique agricole en forêt tropicale dense et en contexte multiculturel." Aix-Marseille 3, 2004. http://www.theses.fr/2004AIX32074.
Повний текст джерелаFavreau, Jean-Luc. "Durabilité des exploitations en agriculture biologique : une analyse de la diversité des situations et des trajectoires d'évolution en Midi-Pyrénées." Phd thesis, Université Toulouse le Mirail - Toulouse II, 2013. http://tel.archives-ouvertes.fr/tel-01058072.
Повний текст джерелаDa, Cunha Charlotte. "Quelle prise en compte de la diversité dans les enjeux de performances de l'activité agricole en Ile de France? : expérimentation d'une démarche d'évaluation participative multicritère." Versailles-St Quentin en Yvelines, 2010. http://www.theses.fr/2010VERS020S.
Повний текст джерелаIn this International Year of Biodiversity, biodiversity is more than ever considered in scientific and institutional literature, as an irreducible element of sustainability that must be integrated in all economic sectors. This thesis aims at arguing and testing a participatory multi-criteria approach to understand how the environment, including biodiversity, can be taken into account in agricultural activities. Based on two case studies on different scales (territory and farm), this thesis examines to what extent biodiversity is integrated by actors of agricultural activities. These applications show that the proposed approach is an efficient tool for identification of their issues, which reveal a weak consideration of biodiversity concerns
Peres, Guénola. "Identification et quantification in situ des interactions entre la diversité lombricienne et la macro-bioporosité dans le contexte polyculture breton. Influence sur le fonctionnement hydrique du sol." Rennes 1, 2003. https://tel.archives-ouvertes.fr/tel-00007432.
Повний текст джерелаAlmoussawi, Ali. "Importance relative des processus de dispersion et de recrutement dans la dynamique d'assemblage des communautés végétales en paysage agricole." Thesis, Amiens, 2019. http://www.theses.fr/2019AMIE0043.
Повний текст джерелаThe absence of a species from a focal community may be due to either dispersal limitation or recruitment limitation. The present work aims to assess species behavior in different types of landscapes. I first investigated the relationship between alpha and gamma diversity at different scales and for different fragmentation levels in forest fragments embedded in an agricultural landscape matrix. Results highlight the importance of considering species identity when studying the effect of fragmentation on the plant community structure. I then assessed the germination success and persistence of vascular plant species (weeds and herbaceous plants), using semi-controlled experiments. In the first experiment, I studied the germination and persistence success of sown weed species, and their subsequent effect on crop yield, under contrasted agricultural practices. We evidenced a sorting effect of agricultural practices on local plant species composition. In the second experiment, I assessed the potential of hedgerows to serve as habitats for forest plant species. We sought seeds and transplanted seedlings in both hedgerows and forest to monitor germination and persistence, respectively, each time with and without resident vegetation removal to further assess the role of competition. Our preliminary results show that few species germinate and survive in hedgerows, suggesting that both dispersal and recruitment limitations are at play. Results from this work emphasize the importance of community assembly processes in ecosystem conservation and maintaining its delivered services
Le, Provost Gaëtane. "Effets des changements d'utilisation des terres sur la biodiversité fonctionnelle des prairies en paysage agricole." Thesis, La Rochelle, 2017. http://www.theses.fr/2017LAROS033.
Повний текст джерелаUnderstanding how grassland biodiversity responds to land use intensification is crucial for both biodiversity conservation and the management of key ecosystem services in agricultural landscapes. My PhD aims at (i) identifying and generalising the effects of land use intensification operating at different spatial and temporal scales across multiple taxonomic groups and trophic levels (plants, herbivores, pollinators, predators and top-predators) ; (ii) investigating the underlying mechanisms of biodiversity response, and particularly the role of trophic interactions. We used multiple functional traits related to resource acquisition, the size of the organisms and their mobility. We tested how multitrophic functional trait diversity responded to landscape history, composition and heterogeneity. Considering multiple taxonomic groups simultaneously, our study brings out a clear response of overall biodiversity to land use intensification. We found that legacy effects of land use intensification operating at the landscape scale are major drivers of present-day multitrophic functional trait diversity in agricultural landscapes. By considering a core set of organismal traits reflecting similar functions across trophic levels, our approach reveals multiple dimensions by which land use intensification filters out biodiversity over time and allows us to generalise its effect across multiple trophic levels and trait-spectrum. Finally, trait-based approach allowed us to assess the importance of trophic interactions and their contribution in shaping animal communities in agricultural landscapes
Torres, Alvarez Maria de. "Humains, bovins et prairies naturelles : une histoire commune de réciprocité et d'échange marchand." Thesis, Montpellier 3, 2017. http://www.theses.fr/2017MON30006/document.
Повний текст джерелаThe PhD project will contribute to the understanding of livestock transformations in Uruguay from the anthropological and the micro-ecosystem analysis of human-animal relationships and different types of knowledge associated with development models proposed by public policies. Different types of farming in Uruguay currently coexist and are characterized by specific rules of relationships with animals and the ecosystem based on differentiated knowledge registers. The research hypothesis argues that the intensification process tends to substitute practices and reciprocal relationships through mercantile exchange relationships that increase the vulnerability of the farming system as socio-ecosystems, based on criteria remote technology from the practical experience and local knowledge. The project proposes an ethnography of human-animal-ecosystem relationships and their transformation in the north part of Uruguay and two institutions from the executive that direct public livestock policy
Pujol, Benoît. "Dynamique évolutive de la diversité morphologique et génétique d'une plante domestiquée à "propagation végétative" : Le manioc (manihot esculenta crantz)." Montpellier 2, 2004. http://www.theses.fr/2004MON20125.
Повний текст джерелаMarage, Damien. "Déterminisme, dynamique et modélisation spatiale de la diversité floristique dans un contexte de reprise pastorale : application à la gestion durable des espaces montagnards sous influence méditerranéenne." Paris, ENGREF, 2004. https://pastel.archives-ouvertes.fr/pastel-00000906.
Повний текст джерелаIn European mountain, the pastoral activity decreases unrelentingly. The post-cultural succession modifies the structure and functionning of vegetation, deriving as well in its contents as in its expression, of a traditional use. The sustainable management of this lands in constant change must avoid calling into question their taxonomic and ecological persistence. The study was carried out in a watershed call « Petit Buëch » located in the Hautes-Alpes (France), and registered in the Natura2000 network. To assess, analyse and monitor this site and associated threatened species, we had using statistical modelling techniques, to understand the patterns of plant species and their richness. The explanatory factors used in the models were physical and bioclimatic variables derived from a digital elevation model (DEM) and from land use history, all constructed in a 50 m-resolution GIS environment. GLM (generalized linear models) were used to construct the models using a forward stepwise procedure. The models are discussed in the context of current theories on species richness and vegetation dynamics. Modeling of threatened species, vegetation and plant species richness based on areal photographers and GIS can provide useful information needed in land use planning and policy-makers
Pépin, Antonin. "Performance environnementale de fermes maraichères en Agriculture Biologique." Electronic Thesis or Diss., Rennes, Agrocampus Ouest, 2022. https://tel.archives-ouvertes.fr/tel-04059580.
Повний текст джерелаFrench organic vegetable farms are diverse, ranging from complex agroecological systems based on biodiversity and producing many different vegetables, to simple systems based on inputs and producing few different vegetables, suggesting different environmental impacts. The objective of the thesis is to assess the environmental performance of contrasting organic vegetable farms, using life cycle assessment (LCA). The thesis is organised as follows: (1) the characterisation of the diversity of organic vegetable farms, using a typology based on surveys and a framework for analysing farming system diversity; (2) the adaptation of a biodiversity assessment method to vegetable farming; 3) the assessment of three contrasting farms using a LCA "system" approach, considering the farm as a whole and in which all inputs, operations and emissions are related to the total annual production. The analysis of the impacts, expressed per kg of vegetable, ha of farmland and economic value expressed in Euro, on climate change, marine eutrophication, biodiversity, cumulative energy demand and plastic use, revealed large differences between the systems for their main impact contributors, but did not allow a clear ranking of the three farms. The LCA "system" approach corresponds to the agroecological functioning and addresses the challenge posed by the complexity of some vegetable farms. The plastic use indicator shed new light on a growing concern
Calbrix, Raphaël. "Impact des intrants organiques et des conduites culturales sur la biomasse microbienne et la diversité des bactéries telluriques." Rouen, 2005. http://www.theses.fr/2005ROUES028.
Повний текст джерелаThe aim of this work is to analyse the effects of four different organic products (turkey manure, compost of turkey manure and ligneous wastes, sewage sludge and compost of sewage sludge) on soil microbial communities in function of agricultural managements, during a 24 months kinetic. The microbial communities were characterised in a quantitative point of view (enumeration of heterotrophic cultivable bacteria, assay of soil total, microbial carbon assay) and in a qualitative one by potential metabolic fingerprinting (Biolog) and genetic structure of soil bacterial communities (T-RFLP 16S rDNA). A transitory impact specific to the different organic products was shown. The impact of organic products on microbial biomass and on bacterial community structure seemed to depend on their rate of lignin (Van Soest) and of mineralisable carbon. The influence of the tillage and the vegetation was revealed by the evolution of bacterial community structure during the 24 months of the experiments
Lavie, Muriel. "Les effecteurs de type III de la famile AvrRxv/YopJ de Ralstonia solanacearum : étude fonctionnelle et contribution à la biodiversité de l'espèce." Toulouse 3, 2003. http://www.theses.fr/2003TOU30166.
Повний текст джерелаTaugourdeau, Simon. "Effects of management and climate on the plant functional diversity related to ecosystem services of permanent grasslands in Europe." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0039/document.
Повний текст джерелаPermanent grasslands can provide a large diversity of ecosystem services. They are found in contrasted conditions in terms of management and climate in Europe. These conditions induce a wide variety of grassland types that differ in their vegetation and are expected to differ with respect to the provision of ecosystem services. Because ecosystem functioning in grassland has been shown to be linked to plant functional diversity criteria, we put forward that these functional diversity criteria can be used to evaluate the provision of ecosystem services. These criteria are influenced by the management and the climate. The overall objective of this PhD program is to assess the effects of management and climate on the plant functional diversity related to ecosystem services of permanent grasslands. The first step of the PhD program was to select 29 functional diversity criteria related to 8 ecosystem services (quantity of forage, forage quality, stability of the forage production, biodiversity conservation, pollination carbon sequestration, dryness resistance and nitrogen fertility). This selection was made using experts' interview and literature survey. The second step was to evaluate inaccuracies in the calculation of the 29 functional diversity criteria from functional trait databases and different sets of botanical surveys. The third step was to estimate the functional diversity criteria from management and climate data using "Random Forests" methodology. The results show that the climatic variables had generally more effect on the functional diversity than the management ones. Furthermore, for some climatic conditions, the management does not affect some functional diversity criteria. Among the 29 functional diversity criteria, only 8 have more than 40 % of their variance explained by the management and climate variables
Vaquié, Agathe. "Diversité intra- et interspécifique dans les systèmes céréaliers et ses effets sur la régulation des ravageurs." Thesis, Paris, Institut agronomique, vétérinaire et forestier de France, 2019. http://www.theses.fr/2019IAVF0008/document.
Повний текст джерелаIncreasing intrafield plant diversity has been shown to regulate pest populations in various agroecosystems. Polyvarietal mixtures of a crop species (intraspecific diversity) or associations of a crop and a companion plant (interspecific diversity) are both considered as promising agroecological practices for low-input or organic agriculture systems by providing several ecosystem services such as pest, disease and weed control, and nitrogen fertilization. However, combining both diversification practices has not been studied yet in perspective of winter wheat pest control.In organic field experiments over two growing seasons, we combined both practices and examined the direct impact on aphid and natural enemy populations and on wheat production. We also investigated the potential pest regulation service through the assessment of the rate of predation by using sentinel preys.Results show that combining intra- and interspecific diversity did not outperform each practice individually in reducing aphid populations, thus not clearly showing synergetic effects. Taken separately, intercropping tended to have lower aphid infestation, while it the cultivar mixtures was more infested by aphids than the least susceptible cultivar. Yearly variation in climatic conditions strongly impacted wheat and clover development, as well as the appearance of aphid peaks. Wheat yields and grain nitrogen content were reduced in intercropping by 7 to 10%, but not in cultivar mixtures. Functional biodiversity, especially natural enemies such as ground beetles, tended to be positively correlated to the presence of a clover cover in the wheat fields (interspecific diversification), but did not respond to the wheat cultivar mixture (intraspecific diversification). Results varied according to the family of arthropods concerned and their position within the vegetation layer (ground dwelling or foliage dwelling arthropods). The cover of white clover and the field context influenced the community composition of predatory ground dwelling beetles. Rates of predation on sentinel preys were not influenced by any of the diversification practices.Under laboratory conditions, we evaluated how combining wheat and legumes (clover or pea) modifies the behaviour of the cereal aphid Sitobion avenae in terms of host-plant location, and population growth. We observed that aphids’ residence time on wheat was decreased when this host-plant was intercropped with clover. At the population level, wheat-legume intercrops reduced the number of aphids on wheat plants compared to wheat sole crops but if we take into account plant biomass, only intercropping clover with wheat significantly reduced aphid densities on wheat. The species used as non-host plants and their density are important parameters that should be taken into account in studies on intercropping systems and that may explain the large variability in the results observed in the literature.Our findings suggest that intrafield diversification may regulate wheat aphids to some extent, but combining the two diversification practices did not result in an interesting trade-off between pest regulation and wheat production in real farming conditions
Damien, Maxime. "Favoriser les ennemis naturels de ravageurs par la diversité végétale dans un contexte hivernal." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B027/document.
Повний текст джерелаIntensive agriculture and global warming induced deep modifications in the agricultural landscapes’ biodiversity and trophic system structures, resulting in the loss of several ecosystem services such as pest biological control. Conservation biological control aims to restore trophic systems’ stability within arable lands by using plant diversity and creating functional habitats for natural enemies. This thesis aimed at identifying how vegetal diversity and its management during the winter season could favor aphids’ natural enemies in cereal intensive agricultural landscapes from the west part of France. Laboratory research and a follow-up of populations over three consecutive winters led to significant results, further developed in this thesis. The experimental laboratory research showed that the selection of the flower diversity used in sown winter cover crops should take into account their functional traits. It is indeed necessary to use a variety of species, thus combining attractiveness and profitability for the aphid’s parasites present in the agricultural mosaic during wintertime. At the field scale, studies demonstrated that warmer winter conditions are also favoring the activity of generalist ground dwelling predators, as well as that of parasitoids. The implementation of functional habitats, through the selection of an adequate plant diversity better adapted to the changing climates and to the aphids’ natural enemies’ needs, allowed to support the ground predators’ activities. Consequently, their increased activity should contribute to the early regulation of aphid populations, allowing to decrease the intensity of their population dynamics during the growing seasons. The results obtained in this thesis suggest that winter constitutes a favorable period/season for the development of new methods within the conservation biological control framework/biological control framework for conservation in temperate climatic areas
Marage, Damien. "Déterminisme, dynamique et modélisation spatiale de la diversité floristique dans un contexte de déprise pastorale. Application à la gestion durable des espaces montagnards sous influence méditerranéenne." Phd thesis, ENGREF (AgroParisTech), 2004. http://pastel.archives-ouvertes.fr/pastel-00000906.
Повний текст джерелаCouly, Claire. "La biodiversité agricole et forestière des Ribeirinhos de la Forêt Nationale du Tapajós (Pará, Brésil) : usages, gestion et savoirs." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2009. http://tel.archives-ouvertes.fr/tel-00597906.
Повний текст джерелаAtiama, Morguen. "Bioécologie et diversité génétique d'Orthops palus (Heteroptera, Miridae), ravageur du manguier à La Réunion." Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0007/document.
Повний текст джерелаMango crops in Reunion Island are threatened by a series of pests, including the bug Orthops palus (Heteroptera, Miridae). This species has only been reported in Uganda and Reunion Island but is considered pest of mango only in Reunion Island. Few studies have therefore been devoted to this bug, which explains the lack of knowledge concerning this pest. The overall aim of my thesis was to acquire knowledge about O. palus, and several specific objectives were pursued. The first was to characterize mirid diversity in the mango orchards of Reunion Island. The second was to characterize the life cycle of O. palus and insect-plant interactions. The third objective was to study the distribution and genetic diversity of the species in Reunion Island and on other islands in the south-west Indian Ocean (SWIO).The main results of these studies are: among the 13 species identified in the community of mirids in mango orchards, O. palus was the most abundant on the mango inflorescences when in flower. Three original tools were built to identify O. palus in the laboratory and to recognize the species in the field: an identification key, COI sequences, and a field recognition card). A method was developed to rear O. palus, which enabled the characterization of its life cycle and the length of the development stages. Meanwhile, the inventory of in situ host plants (15 species in Reunion Island) showed that O. palus is polyphagous. Studies of the diversity and genetic structure of O. palus in SWIO islands also provided significant results. In Reunion Island, the population is structured in two clusters, although the structural factors could not be fully identified. In Mauritius, one cluster was identified and was shown to be different from the clusters in Reunion Island. No host race was found either in Reunion Island or in Mauritius. Population movements in both directions between the two islands were highlighted. Finally, the analysis of the mitochondrial DNA diversity of individuals sampled on four SWIO islands (Reunion, Mauritius, Mayotte, Grande Comore) revealed the presence of at least seven haplotypes whose distribution confirmed exchanges between islands.The dynamics of O. palus in space and over time are discussed in connection with its survival strategy over the course of the year and with population flows across SWIO. The results showed that beyond being a bug that attacks only the mango tree, as the name strongly suggests, O. palus is rather a "flower bug" likely to maintain populations throughout the year by moving from one flowering plant to another according to food availability. Among the plants involved in the annual dynamics of the insect, several species beside mango are of economic interest (lychee, jujube, avocado). Several research topics are proposed to complete the knowledge already acquired on O. palus, including understanding of population dispersion processes at the scale of the agro-ecosystem, and evaluating the presence and the genetic diversity of O. palus in other SWOI territories. Finally, agroecological practices for the local management of O. palus populations are proposed based on the results of the studies that comprise the present dissertation. Recommendations are made for precautionary measures to prevent the flow of O. palus populations between countries located in the Indian Ocean
Bourgeois, Emilie. "Contribution au développement de bioindicateurs microbiens pour l'évaluation de l'impact de pratiques agricoles sur les sols." Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS063/document.
Повний текст джерелаSoil is the support of agricultural production. It performs many functions essential to the provision of ecosystem services necessary for the well-being of our societies. Soil physicochemical and biological properties have been altered by the development of intensive agriculture while it is a non-renewable resource, revealing the need to develop new management practices suitable for the sustainability of soil quality. This also marked the entry into the “Agroecology” era, which promotes the development of new agricultural systems optimizing services provided by biodiversity to reduce the use of inputs and energy use. To achieve this aim, the development of a range of indicators to assess the impact of agricultural practices on the biological quality of the soil is essential. This thesis, which aims to contribute to the development of microbial bio-indicators of soil quality, is a part of this agroecological context. The choice to work on microbial communities is fully justified because they are (i) present with a high abundance and diversity in all environments, (ii) heavily involved in biological functioning and the soil ecosystem services, (iii) they respond very sensitive to changes in environmental conditions in terms of biomass, diversity and activity. They therefore have significant potential in terms of bio-indicators of development. This work has focused specifically on the evaluation of two complementary bioindicators: (i) the microbial molecular biomass and (ii) the microbial taxonomic diversity. In a first part we tested the robustness of these two bioindicators by assessing the biases associated with each of the procedure technical steps used for their measurement. We then used these bioindicators in different agricultural contexts to assess their sensitivity. A first work has followed the rehabilitation of microbial patrimony of a polluted soil irrigated for a hundred years by sewage, by implanting a bioenergy crop. A second application has focused on the impact of different agricultural practices on microbial communities depending on the intensity of tillage (tillage vs. reduced tillage), management of crop residues (export vs. restitution), and the crop type (annual vs. perennial). Results highlighted that microbial molecular biomass and microbial taxonomic diversity achieved by high throughput sequencing are both robust and sensitive bioindicators to describe the microbiological quality of agricultural soils in very different contexts. Both bioindicators allow evidencing soil disturbances but also the positive impact of innovative practices. They may therefore represent powerful tools for the assessment of agricultural systems, helping to improve their long term management, allowing a sustainable use of resources provided by soils
Le, Thi Huong. "Impact of land use change and agricultural practices on aquatic microbial diversity and functioning in a tropical system." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1203/document.
Повний текст джерелаLand use (LU) change towards non-sustainable agricultural practices enhances soil degradation, erosion, and the loss of soil microbial diversity. However, the impacts of LU change on in-stream microbial community structure remain poorly understood, particularly in tropical ecosystems. Through controlled experiments and in situ investigations, I assessed how different LU and agricultural practices, via hydrological processes, affect the quantity and quality of stream dissolved organic matter and associated microbial community structure. The results of this work show the importance of considering both past and present LU along with hydrological processes when assessing stream microbial diversity and metabolic capacities. While the experiments in controlled conditions (micro- and mesocosms) allowed disentangling the relative importance of direct overland flow and soil community on stream bacterial structure, the in situ approach gave an integrated view of these processes at the basin scale. This emphasizes the need to use sustainable LU management practices if we wish to mitigate off-site impacts on downstream aquatic systems
Champagne, Nancy. "Évaluation de la diversité entomologique au sol et effet de la modification de la gestion des végétaux sur les insectes le long d'emprises autoroutières de trois milieux différents (agricole, forestier et périurbain) dans le sud du Québec (Canada)." Thèse, Université du Québec à Trois-Rivières, 2003. http://depot-e.uqtr.ca/4018/1/000104323.pdf.
Повний текст джерелаSergent, Denis. "Etude du comportement du Sauvignon et du Sémillon selon la diversité géologique et agro-pédologique de la région des Graves : incidences du climat et des sols sur le comportement de la vigne, la maturation des raisins et les vins." Bordeaux 2, 1996. http://www.theses.fr/1996BOR20453.
Повний текст джерелаGonzalez, Maya. "Diversité des plantes ligneuses de fragments forestiers dans les côteaux de Gascogne : importance des facteurs locaux et du contexte paysager." Toulouse 3, 2006. http://www.theses.fr/2006TOU30103.
Повний текст джерелаThe woody plants of the forest fragments in agricultural zone partly condition the presence and the diversity of other forest organisms. This work is centred on the study of the diversity of woody species and its determinants on three levels of organization: the wood, the stand and the micro-site of regeneration. On the level of wood, the richness of woody species is mainly related to the surface of wood. Late-successionnal species are sensitive to the distance to wood sources. At stand level, the richness and the composition are connected to the soil quality and the exposure. On the level of regeneration micro-site, the identity of the reproducers and the distance to the edge determine the diversity of woody species under cover. The found relations are improved by using regroupings of species based on their life history traits. The diversities found on these three scales are dependent on the successionnal state of the stands
Msanda, Fouad. "Ecologie et cartographie des groupements végétaux d'Anzi (anti-atlas occidental, Maroc) et contribution à l'étude de la diversité génétique de l'arganier (Argania spinosa (L. ) Skeels)." Grenoble 1, 1993. http://www.theses.fr/1993GRE10084.
Повний текст джерелаFilippi-Codaccioni, Ondine. "Impact des pratiques agricoles et de l’urbanisation sur les communautés d’oiseaux agricoles." Paris 6, 2008. http://www.theses.fr/2008PA066440.
Повний текст джерелаPaut, Raphael. "Analyse des compromis entre diversité cultivée et complexité de gestion à travers le cas d’étude du Verger-Maraîcher : Une approche combinant modélisation et méthodes qualitatives Reducing risk through crop diversification: an application of portfolio theory to diversified horticultural systems Modelling crop diversification and association effects in agricultural systems." Thesis, Avignon, 2020. http://www.theses.fr/2020AVIG0724.
Повний текст джерелаThe need to redesign more sustainable agricultural systems able of producing more, especially through intercropping or agroforestry, cannot be achieved without taking into account the essential aspect of production variability. Yet, although many studies have focused on the effect of intercropping on overall production, the particular issue of production variability in such systems remains relatively unstudied. The approach we propose, for a shift towards a sustainable intensification of agricultural systems, considers the dual dimensions of yield and risk in a combined framework for the assessment and the comparison of two diversification strategies: (i) a simple diversification strategy (SDS) considered as an increasing number of crops grown on separate plots within a farm and (ii) an intercropping strategy (IC) considered as a within-plot increased diversity, where more than one species is grown at the same time and place. The two perspectives examined here were Modern Portfolio Theory and Land Equivalent Ratio. The former quantifies the effect of diversification on risk, the latter measures the effect of association on production. This research merges both approaches in a combined framework in order to assess intercropping system performances. By applying our framework to cases selected from the literature, we explored and compared the potential benefits of these two strategies in terms of yield and risk. Results showed that intercropping, in addition to being interesting with regard to yield, can have an additional risk reduction effect compared to a simple diversification strategy. Conversely, some crop mixtures maintained or even increased yield variability. Our work contributes to a better understanding of the possible impacts of diversification strategies on trade-offs between yield and risk, but also underlines the importance of taking yield variability into account in further studies
Mboka, Ingoli Jean-Claude. "Les champs-écoles paysans en Afrique subsaharienne : une approche d'analyse des réseaux complets." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36943.
Повний текст джерелаFavre-Bac, Lisa. "Rôle de corridor écologique des fossés pour la dispersion des espèces végétales dans les paysages agricoles." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S053/document.
Повний текст джерелаThe establishment of ecological networks is considered as one of the solutions to mitigate the negative effects of fragmentation on biodiversity. In agricultural landscapes, non-crop linear elements may form large networks, and constitute refuge habitats and/or dispersal corridors for plant species. The objective of this study is to understand which role may a dense drainage ditch network play for the maintenance and dispersal of plant species in an intensive agricultural landscape located in northern France. In addition, we also investigated the impact of landscape characteristics, network connectivity and plant species life-history traits on propagule dispersal within the ditch network. Our results indicate that ditches are indeed ecological corridors for plant species. By focusing more specifically on hydrochorous species, we demonstrated that they essentially depend on ditch network composition and connectivity and on elements immediately adjacent to the banks. The network also drives patterns of gene flow for two ditch bank plant species. Finally, our results also indicate that species’ response to ditch network connectivity depends on a combination of dispersal traits, and that connectivity reduction leads to functional convergence of those traits at the metacommunity scale. Together, these results provide a better understanding of the corridor role of ditches for plant species, in order to include these features into ecological network planning in agricultural landscapes
Morales, Sonya. "La qualification et le traitement légal des ressources phytogénétiques au bénéfice de la sécurité alimentaire mondiale durable : regard critique sur leur gestion." Doctoral thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26751.
Повний текст джерелаSausse, Christophe. "L'assolement influence-t-il la qualité des paysages agricoles pour les oiseaux nicheurs ? Estimations à partir de bases de données nationales." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLA009.
Повний текст джерелаThe management of crop mosaic could improve the quality of agricultural landscapes for birds, and more generally for biodiversity. Knowledge is available at the field (crop suitability) and national scales (trend analysis), but few at the landscape scale. We therefore linked the French Breeding Bird Survey on about 500 landscapes of 400 hectares, with a high-resolution multi-years land use database. Response models linking birds to crop mosaics were set, based on the variations between separate landscapes (synchronic models), and the variations of landscapes from one year to the other (diachronic models). We found that the information on crop suitability did not allow for prediction at the landscape scale and that the synchronic responses were stronger than diachronic ones, sometimes opposite. We deduced a disjunction between the landscape quality for birds and the immediate effect of its attractiveness under crop influence. Synchronic responses were modest, and varied with the landscape and geographical contexts. They were more pronounced in complex landscapes with grass and hedges, and for farmland birds compared to the whole bird community. We found that the responses to crop diversity were positive or neutral. The interest of the models taking into account explicitly the interactions between crops allows us to suggest that the crop suitability is not invariable but depends on the crop combination. The signals detected by this study were low and should be interpreted as trends that do not allow advice in specific situations. However, the results challenge some simple models used to perform biodiversity assessments on territories or agri-food and feed chains
Carrié, Romain. "Hétérogénéité des paysages et des pratiques agricoles - Effets sur la diversité des abeilles sauvages et la pollinisation." Thesis, Toulouse, INPT, 2016. http://www.theses.fr/2016INPT0104/document.
Повний текст джерелаThe ecological and agricultural importance of wild bees in farmlands stresses the needs for management strategies for these insect pollinators. Wild bees use multiple habitats in agricultural landscapes, such as semi-natural habitats (woodlands, hedgerows, permanent grasslands) and crop fields. This study aims to characterize the community structure of wild bees and assess pollination delivery along gradients of landscape heterogeneity – based on the composition and configuration of semi-natural habitats – and landscape-wide intensity of farming practices. Using a trait-based approach, based on traits determining resource-use by wild bee species, we showed that i) the least mobile species, solitary bees and ground-nesting species were more abundant in crop fields surrounded by large amounts of little-fragmented permanent grasslands, ii) crop fields surrounded by high amount of woodland edges supported a greater abundance of little-mobile bee species, late-emerging bees, social bees and polylectic bees, iii) oligolectic bee species were filtered out in highly forested landscapes, because these species could thrive on resources provided by the crop mosaic. We also found that the positive effect of the proportion of semi-natural habitats on bee diversity was greater in landscapes with intensively managed crop mosaic. Moreover, we showed that the local intensity of farming practices had as much influence on bee diversity as the proportion of semi-natural habitats. Finally, we showed that, depending on situations, the abundance fluctuations of dominant bee species or the occurrence of an assemblage of uncommon bee species can explain variations in pollination success. In the cases where pollination success responded to the occurrence of uncommon species, the proportion of semi-natural habitats had a positive influence on pollination delivery provided by wild bees. This study shows the importance of some uncommon species, dependent on semi-natural habitats, for pollination delivery but also the positive relationship between the abundance of some species groups and the proportion of semi-natural habitats. This work therefore confirms the hypothesis that semi-natural habitats sustain the diversity of wild bee communities and pollination delivery. However, the positive effect of semi-natural habitats on bee diversity depends on farming practices at the local and landscape scale. Therefore, recommendations on the management of landscape heterogeneity and changes in farming practices cannot be given independently from each other
Gaujour, Etienne. "Evaluation des sources d'espèces et des déterminants de la diversité végétale des parcelles agricoles : interchamps, stock semencier, pratiques agricoles et paysage de l'Installation Expérimentale Inra ASTER Mirecourt." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL020N/document.
Повний текст джерелаOne of the means to offset the decrease of pesticide use is to favour agro-ecological services of plant diversity. In this aim, farmer will have to adapt its farming management. My work partly answers to the following applied objective: to bring to the farmer some advices for the management of plant diversity on the farm territory. I have two scientific objectives: i) to verify if field boundaries and soil seed bank are potential sources of plant species for field centres; ii) to quantify the relative influence of dynamics of two factor groups, characterized as field paths, on plant diversity: farming practices and characteristics of landscape mosaïc.I have carried out this study on the experimental farm of INRA ASTER Mirecourt. Its farming systems (mixed crop-dairy systems) have been converted to organic farming since 2004. I have characterized vegetation - established vegetation in field boundaries and in field centres, and vegetation in the soil seed bank - of permanent grasslands and arable fields with complementary approaches: taxonomical approach based on the species, and functional approach based on seven functional properties about dispersal, establishment and persistence of plant species. I have characterized field paths, along nine years, either from farming practices set up on field, either from annual characteristics of landscape mosaïc. I have represented this landscape mosaïc as a mosaïc of distinct land-uses. All of them and their spatialization have been determined from farmer surveys or landscape observations.My results show that soil seed bank and field bboundaries are not potential sources of plant species for field centres, in both permanent grasslands and arable fields. On the other hand, they are efficient refuges for a large part of grassland species. According to my results, I hypothesize that field boudaries are species sinks in arable fields. I also highlight that functional gradient of grassland vegetation in the field edge, between field margins and field centres, is spread until 2 m only.Finally, plant diversity in studied fields is mainly influenced by field path according landscape mosaïc and by farming practices set up the same year of vegetation sampling. Soil characteristics have a minor influence. These three groups of influent factors explain more than 75 % of the functional composition variability of the vegetation in field centres.The management of plant diversity in agricultural fields of a given farm can be partly reach by the farmer. However, according to the effects of field paths about landscape mosaïc, it is necessary to set up a collective management of plant diversity with all actors sharing the studied territory
Plassart, Pierre. "Pertinence des indicateurs microbiens dans l'évaluation de l'état des sols agricoles." Rouen, 2010. http://www.theses.fr/2010ROUES048.
Повний текст джерелаMost soils worlwide undergo modifications caused by human activities. For numerous agricultural soils, the intensive practices, as well as the chronical spreading of chemical inputs, lead to a decrease in these soils fertilkity. Yet, while these soils are in danger, only a few relevant soil status evaluation tools exist. The biological component has been neglected for a long time, though soil accomodates a high diversity level of organisms involved in biogeochemical cycles. Among these organisms, microorganisms are likely to be potential bioindicators of soil status. Thus, the aim of this work consists in identifying biological variables describing bacterial diversity that would be sensitive to soil status. Bacterial community structure (abundance, genetic and functionnal diversity) was assessed as a whole, but also through the analysis of Pseudomonas populations, a bacterial genus widely found in soils and sensitive to environmental disturbances. The experimental approach, from the field plot level to the microcosm level, consisted in the confrontation of the impacts of (1) soil copper contamination (agronomical dose x100), (2) natural disturbances (spatial and climatic), and (3) human caused disturbances (agricultural practices) on bacterial communities. The first part of this work was performed in situ on typical silty Haute-Normandie soils managed as grasslands and cultures, in order to define the natural spatial and temporal variation limits of different bacterial descriptors. Besides, this first part enabled the understanding each variable's sensitivity, and validated the different methodological approaches. Thus, the measured variables can be organized in two categories: those which rely on microorganisms cultivation would reflect recent soil disturbances, while those based on molecular approaches would reflect the agricultural history of field plots. In the second part, the impact of a copper contamination on the previously described variables was studied in microcosms. Results showed that variations in the bacterial community structure caused by a single copper contamination were minor, when compared with variations caused by season or agricultural practices. In the same time, a comparative analysis was performed between sieved soil and intact soil microcosms. This revealed that soil status can influence bacterial communities response to a copper contamination; indeed, soil physical disturbance (sieving) induced a transient response of bacterial communities to the copper contamination. This work lead to (1) building, for an agricultural silty soil, a microbiological reference system, which includes spatial and temporal fluctuations of the measured variables, (2) determining for each variable its sensitivity to natural and human impacts, and identifying the limits and complementarities of the cellular and molecular approaches, (3) organizing into a herarchy factors determining the genetic and functionnal sructure of bacterial communities, (4) validating the relevance of using the Pseudomonas genus in the evaluation of the impact of copper on soils
Estébanez, Virginie. "Typologie et activité des populations microbiennes nitrifiantes issues des procédés de traitement biologique des effluents agricoles et industriels." Rennes 1, 2011. http://www.theses.fr/2011REN1S008.
Повний текст джерелаThis work describes the characterization of the nitrifying microbial community of nineteen treatment plants treating municipal or industrial food processing wastewaters. Activated sludges were analyzed for their maximal activities of nitritation and nitratation by liquid respirometry. While the activated sludge from municipal and livestock WWTPs exhibit similar activities within each group, the other treatment plants have very different activities. The diversity and quantity of nitrite and nitrate oxidizing communities were studied by T-RFLP and real-time quantitative PCR. Between the sites studied, differences in community structure are shown. The nitrite oxidizing biomass is, for all activated sludges, composed of bacteria and archaea, but with different ratios from one plant to another. The majority of the sludges shows a community of nitrite oxidizing bacteria dominated by the genus Nitrosomonas. The few stations with a dominance of Nitrosospira have activities of nitrite and nitrate oxidation close to zero or very low. This correlation between the presence of Nitrosospira and a potential problem in nitrification activity should be verified on site to quickly detect problems in the treatment of nitrogen. This analysis also shows that half of the stations of this study present a community of nitrite-oxidizing bacteria composed of Nitrospira and Nitrobacter. Among all the quantified populations, only the number of nitrite oxidizing bacteria correlates with the activity of nitrification. These bacteria therefore represent the community responsible for nitrification
Duflot, Rémi. "Hétérogénéité fonctionnelle et biodiversité : quel est le rôle des interfaces ou lisières dans les paysages agricoles ?" Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-01019974.
Повний текст джерелаPortas, Marlène. "Diversité phylogénétique et fonctionnelle des Eumycètes dans les écosystèmes pélagiques." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2010. http://tel.archives-ouvertes.fr/tel-00769938.
Повний текст джерелаMarineau, Annie. "Étude de la diversité entomologique au sol de bandes riveraines situées en zones agricoles dans le sud du Québec." Thèse, Université du Québec à Trois-Rivières, 2000. http://depot-e.uqtr.ca/3085/1/000677382.pdf.
Повний текст джерелаVASILEIADIS, SOTIRIOS. "Riflessione sugli effetti della diversità funzionale dei procarioti e della filogenesi dei suoli agricoli sui servizi ecosistemici. Approcci basati sull’uso di tecniche PCR nello studio dell’ecologia dei procarioti." Doctoral thesis, Università Cattolica del Sacro Cuore, 2012. http://hdl.handle.net/10280/1313.
Повний текст джерелаSoil is a complex environment comprising the basis for several ecosystem services, with many of them being connected to agricultural production. This complexity is reflected on the composition and functions of the hosted microbial life mainly responsible for the acquired services. Aim of the described studies was to explore microbial community responses to ecosystem services related human intervention in agricultural soils. Total prokaryotic diversity was studied in soils of common origin, which diverged in properties during the late 6-7 centuries due to different land use and management. For achieving this, related DNA markers were screened with high throughput sequencing. Cultivated environments had increased diversity compared to more natural soils. Factors potentially affecting the microbial community structure were: soil disturbance events; available nutrients; and microbial dormancy. In a second approach, ammonia oxidizing prokaryotes were used as biomarkers for studying stress effects caused by humidity and increased zinc concentrations and also the presence of organic pesticides in soil and litter respectively. In both referred cases the studied microbial guilds responded to the applied stresses showing strain or taxon level functional redundancy potentials, and tolerance variability. Overall, results show that human intervention is determining for the prokaryotic structure and functions in agricultural soils.
VASILEIADIS, SOTIRIOS. "Riflessione sugli effetti della diversità funzionale dei procarioti e della filogenesi dei suoli agricoli sui servizi ecosistemici. Approcci basati sull’uso di tecniche PCR nello studio dell’ecologia dei procarioti." Doctoral thesis, Università Cattolica del Sacro Cuore, 2012. http://hdl.handle.net/10280/1313.
Повний текст джерелаSoil is a complex environment comprising the basis for several ecosystem services, with many of them being connected to agricultural production. This complexity is reflected on the composition and functions of the hosted microbial life mainly responsible for the acquired services. Aim of the described studies was to explore microbial community responses to ecosystem services related human intervention in agricultural soils. Total prokaryotic diversity was studied in soils of common origin, which diverged in properties during the late 6-7 centuries due to different land use and management. For achieving this, related DNA markers were screened with high throughput sequencing. Cultivated environments had increased diversity compared to more natural soils. Factors potentially affecting the microbial community structure were: soil disturbance events; available nutrients; and microbial dormancy. In a second approach, ammonia oxidizing prokaryotes were used as biomarkers for studying stress effects caused by humidity and increased zinc concentrations and also the presence of organic pesticides in soil and litter respectively. In both referred cases the studied microbial guilds responded to the applied stresses showing strain or taxon level functional redundancy potentials, and tolerance variability. Overall, results show that human intervention is determining for the prokaryotic structure and functions in agricultural soils.
Pervanchon, Frank. "Modélisation de l'effet des pratiques agricoles sur la diversité végétale et la valeur agronomique des prairies permanentes en vue de l'élaboration d'indicateurs agri-environnementaux." Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL061N.
Повний текст джерелаWe set out the hypothesis according which it is necessary to elaborate a mathematical model for the prediction of vegetal diversity and of agronomical value of permanent grasslands. The fmal aim is to set up indicators of permanent grassland management according to the agricultural practices applied there. We demonstrate that multiple regression analysis does not allow obtaining effective models of vegetal diversity. Nevertheless, the prediction of pastoral value is rather effective when considering the environmental factors (pH, moisture, etc. ). However, these results do not concern the mixed grasslands of Lorraine, because of a weak number of available data. Ln order to predict vegetal diversity and agronomic value, we propose a model based on expert systems associated to fuzzy logic. This modelisation is one of the ftrst concrete applications of the theory of functional groups based on life traits of plant species. We show that it is possible to diagnose and predict vegetation (list of vegetal species) and the patrimonial value of grassland, without realizing floristic relevés, by being based only on the life traits already identified in litterature. Lndicators are obtained by reporting the model's results on an abacus ofregional values of vegetal diversity and ofpastoral value