Multi-scale impacts of urbanization on species distribution within the genus Tetramorium     

Cordonnier  Marion  Gibert  Corentin  Bellec  Arnaud  Kaufmann  Bernard  Escarguel  Gilles 《Landscape Ecology》2019,34(8):1937-1948

Landscape Ecology - Urbanization is a global change which deeply impacts landscapes. Long studied through transects along urbanization gradients, ecological response to urbanization can now be...  相似文献   

Climate change will affect the ability of forest management to reduce gaps between current and presettlement forest composition in southeastern Canada     

Boulanger  Yan  Arseneault  Dominique  Boucher  Yan  Gauthier  Sylvie  Cyr  Dominic  Taylor  Anthony R.  Price  David T.  Dupuis  Sébastien 《Landscape Ecology》2019,34(1):159-174

Landscape Ecology - Forest landscapes at the boreal–temperate ecotone have been extensively altered. Reducing the gap between current and presettlement forest conditions through...  相似文献   

Study of Resistance to Orobanche ramosa in Host (Oilseed Rape and Carrot) and Non-host (Maize) Plants     

Naïma Zehhar  Pascal Labrousse  Marie-Claire Arnaud  Christian Boulet  Driss Bouya  André Fer 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):75-82

Orobanche ramosa is a parasitic Angiosperm responsible for severe yield losses in several economical crops. It is a serious threat in oilseed rape in France and Morocco and is appearing in carrot crops in Morocco. In this study, several varieties of oilseed rape and carrot were screened in order to identify resistant cultivars and to characterize the resistance mechanisms involved. All the 15 oilseed rape varieties tested were susceptible. In carrot, the varieties 'Colmar à coeur rouge' and 'Nantaise demi-longue' were susceptible, whereas 'Palaiseau' and 'Buror' were resistant. In the susceptible 'Colmar à coeur rouge' carrot no defence reactions were found and the development of the parasite inhibited carrot tap root formation. In the resistant carrot varieties, the parasite germinated, became attached to the host root but became necrotic before emergence. In 'Buror' carrot, formation of a mechanical barrier was associated with the restriction to the cortex of the parasite. In maize cv. 'Vigni', a non-host of O. ramosa, thickening of xylem vessels, cell divisions in the central cylinder and formation of an encapsulation layer were observed in association with restricted development of Orobanche haustoria.  相似文献   

Management of yellow dwarf disease in Europe in a post‐neonicotinoid agriculture     

Louise Mc Namara  Kevin Gauthier  Lael Walsh  Gaël Thbaud  Michael Gaffney  Emmanuel Jacquot 《Pest management science》2020,76(7):2276-2285

Barley/cereal yellow dwarf viruses (YDVs) cause yellow dwarf disease (YDD), which is a continuous risk to cereals production worldwide. These viruses cause leaf yellowing and stunting, resulting in yield reductions of up to 80%. YDVs have been a consistent but low‐level problem in European cereal cultivation for the last three decades, mostly due to the availability of several effective insecticides (largely pyrethroids and more recently neonicotinoids) against aphid vectors. However, this has changed recently, with many insecticides being lost, culminating in a recent European Union (EU) regulation prohibiting outdoor use of the neonicotinoid‐insecticide compounds. This change is coupled with the growing challenge of insecticide‐resistant aphids, the lack of genetic resources against YDVs, and a knowledge deficit around the parameters responsible for the emergence and spread of YDD. This means that economic sustainability of cereal cultivation in several European countries including France and United Kingdom is now again threatened by this aphid‐vectored viral disease. In this review, we summarize the current knowledge on the YDV pathosystem, describe management options against YDD, analyse the impacts of the neonicotinoid ban in Europe, and consider future strategies to control YDV. © 2020 Society of Chemical Industry  相似文献   

Naturally transmitted herpesvirus papio-2 infection in a black and white colobus monkey     

Troan BV  Perelygina L  Patrusheva I  Wettere AJ  Hilliard JK  Loomis MR  Voe RS 《Journal of the American Veterinary Medical Association》2007,231(12):1878-1883

CASE DESCRIPTION: A 6.5-year-old female eastern black and white colobus monkey (Colobus guereza) was evaluated after acute onset of ataxia and inappetence. CLINICAL FINDINGS: The monkey was ataxic and lethargic, but no other abnormalities were detected via physical examination, radiography, or clinicopathologic analyses. During the next 2 days, the monkey's clinical condition deteriorated, and its WBC count decreased dramatically. Cytologic examination of a CSF sample revealed marked lymphohistiocytic inflammation. TREATMENT AND OUTCOME: Despite supportive care, the monkey became apneic; after 20 hours of mechanical ventilation, fatal cardiac arrest occurred. At necropsy, numerous petechiae were detected within the white matter tracts of the brain; microscopic lesions of multifocal necrosis and hemorrhage with intranuclear inclusions identified in the brain and adrenal glands were consistent with an acute herpesvirus infection. A specific diagnosis of herpesvirus papio-2 (HVP-2) infection was made on the basis of results of serologic testing; PCR assay of tissue specimens; live virus isolation from the lungs; and immunohistochemical identification of the virus within brain, spinal cord, and adrenal gland lesions. Via phylogenetic tree analysis, the colobus HVP-2 isolate was grouped with neuroinvasive strains of the virus. The virus was most likely transmitted to the colobus monkey through toys shared with a nearby colony of baboons (the natural host of HVP-2). CLINICAL RELEVANCE: To the authors' knowledge, this is the first reported case of natural transmission of HVP-2 to a nonhost species. Infection with HVP-2 should be a differential diagnosis for acute encephalopathy in primate monkeys and humans, particularly following exposure to baboons.  相似文献   

Distribution of glyphosate and of its target enzyme inside wheat plants     

Laurence Arnaud  Franoise Nurit  Patrick Ravanel  Michel Tissut 《Pest management science》1994,40(3):217-223

Enolpyruvylshikimate phosphate (EPSP) synthase activity has been measured in different organs of 1–14-day-old wheat seedlings growing in culture chambers. Enzyme activity was first detected after two days, and reached its maximum value at day 4. It remained almost unchanged for 14 days thereafter. During germination, one of the most important sources of enzyme was the seed scutellum. Later, the developed leaves contained 43% of the whole stock of enzyme. Although the enzyme distribution was not identical under light or in the dark, there was no evident light induction of EPSP synthase. High enzyme activity was found in the coleoptile, continuing for the whole life-time of this organ, and which might be associated with its lignification. Five to 40% of the total enzyme was found in the roots, reaching a maximum at 14 days. At this stage, glyphosate applied to the first grown leaf was phloem-transported to the sink organs, with no clear relationship being shown between EPSP synthase activity and herbicide quantity in each organ. At day 4, glyphosate treatment, by soaking the seedlings in the herbicide solution, was followed by an active phloem transport from the scutellum to the growing parts. The average internal concentration of radiolabelled compounds (glyphosate plus its possible derivatives) which induced wheat seedling growth decrease, was shown to reach 50 to 100 μM under our conditions.  相似文献   

Éléments de biologie chez Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 (Nematoda: Pratylenchidae): 2 – Capacités de développement sur hôtes en conditions in vivo et in vitro     

G. Anthoine  A. Buisson  J. P. Gauthier  D. Mugniéry 《EPPO Bulletin》2006,36(2):365-372

La présente étude, portant sur quatre populations sud-américaines de N. aberrans , s'est attachée à comprendre les capacités de multiplication de ce nématode en conditions in vitro (plante développée sur milieu gélosé) et en conditions in vivo (plante développée en pot). Le développement in vitro de N. aberrans est possible dans une gamme non exhaustive de température de 10°C à 25°C, avec un optimum à 20°C, sur de nombreuses plantes d'intérêt agronomique. Toutefois, cette capacité in vitro varie d'une population à une autre et est fortement conditionnée par la pénétration du nématode au stade J2 dans les racines. Les essais in vivo ont montré que la betterave et la tomate sont de très bons hôtes pour toutes les populations testées, alors que d'autres cultures sont favorables à certaines populations (pomme de terre et populations «race pomme de terre>>, poivron et populations «race betterave>>). Enfin, certaines plantes bien que ne présentant pas de symptômes de parasitisme (galles) sont capables d'héberger le nématode en lui permettant d'atteindre le stade J4 sans pour autant réaliser son cycle biologique en entier, ni se reproduire (haricot, concombre). Ces éléments biologiques soulignent le risque réel et majeur d'établissement pour la zone européenne de N. aberrans en cas d'introduction, nématode apte à se développer sur de nombreuses plantes, quel qu'en soit le mode de culture et parfois en l'absence de tout symptôme.  相似文献   

Conifer regeneration in managed temperate mixedwood stands: the balance between release and competition     

Catherine Larouche  Martin-Michel Gauthier  Vincent Roy  Donald Blouin 《New Forests》2015,46(3):409-425

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From small-scale habitat loopholes to decadal cycles: a habitat-based hypothesis explaining fluctuation in pelagic fish populations off Peru   总被引：22，自引：0，他引：22  

Arnaud Bertrand  Marceliano Segura  Mariano Gutiérrez  & Luis Vásquez 《Fish and Fisheries》2004,5(4):296-316

The Peru‐Humboldt Current system (HCS) supports the world's largest pelagic fisheries. Among the world's eastern boundary current systems, it is the most exposed to high climatic stress and is directly affected by El Niño and La Niña events. In this volatile ecosystem, fish have been led to develop adaptive strategies in space and time. In this paper, we attempt to understand the mechanisms underlying such strategies, focusing on the El Niño 1997–98 in Peru from which an extensive set of hydrographic, capture and acoustic survey data are available. An integrated analysis of the data is crucial, as each has substantial shortcomings individually; for example, both catch data and acoustic surveys may easily lead to wrong conclusions. Existing hypotheses on anchovy and sardine alternations lead us to a ‘habitat‐based’ synthetic hypothesis. Using our data, an integrated approach evaluated how fish responded to habitat variation, and determined the consequences in terms of fish‐population variability. Various factors occurring at a range of different spatio‐temporal scales were considered: interdecadal regime (warm ‘El Viejo’/cool ‘La Vieja’ decadal scale); strength and the duration of the El Niño Southern Oscillation event (interannual scale); population condition before the event (interannual scale); fishing pressure and other predation (annual scale); changes in reproductive behaviour (intra‐annual scale); presence of local upwelling (local scale). During El Niño 1997–98, anchovy was able to exploit a small‐scale temporal and spatial ‘loophole’ inside the general unfavourable conditions. Moreover, sardine did not do better than anchovy during this El Niño and was not able to take advantage of the ‘loophole’ opened by this short‐term event. Our results question the traditional view that El Niño is bad for anchovy and good for sardine.  相似文献   

Biodiversity,ecology, fisheries,and use and trade of Tetraodontiformes fishes reveal their socio‐ecological significance along the tropical Brazilian continental shelf     

Leandro Nole Eduardo  Arnaud Bertrand  Thierry Frdou  Alex Souza Lira  Rayssa Siqueira Lima  Beatrice Padovani Ferreira  Frdric Menard  Flvia Lucena‐Frdou 《水产资源保护:海洋与淡水生态系统》2020,30(4):761-774

1. Tetraodontiformes fishes play a critical role in benthic and demersal communities and are facing threats due to anthropogenic impacts and climate change. However, they are poorly studied worldwide. To improve knowledge on the socio‐ecological significance and conservation of Tetraodontiformes a review of literature addressing the diversity, ecology, use and trade, conservation, and main threats of Tetraodontiformes combined with a comprehensive in situ dataset from two broad‐range multidisciplinary oceanographic surveys performed along the Tropical Brazilian Continental Shelf was undertaken.
2. Twenty‐nine species were identified, being primarily found on coral reefs and algal ecosystems. At these habitats, tetraodontids present highly diversified trophic categories and might play an important role by balancing the marine food web
3. Coral reef ecosystems, especially those near to the shelf break, seem to be the most important areas of Tetraodontiformes fishes, concentrating the highest values of species richness, relative abundance and the uncommon and Near Threatened species.
4. Ninety per cent of species are commonly caught as bycatch, being also used in the ornamental trade (69%) and as food (52%), serving as an important source of income for artisanal local fisheries.
5. Tetraodontiformes are threatened by unregulated fisheries, overexploitation, bycatch, and habitat loss due to coral reef degradation and the potential effects of climate change. These factors are more broadly impacting global biodiversity, food security, and other related ecosystem functions upon which humans and many other organisms rely.
6. We recommend the following steps that could improve the conservation of Tetraodontiformes along the tropical Brazilian Continental shelf and elsewhere: (i) data collection of the commercial, incidental, ornamental and recreational catches; (ii) improvement of the current legislation directed at the marine ornamental harvesting; (iii) increase efforts focused on the education and conservation awareness in coastal tourism and communities; and, most important, (iv) creation of marine reserves networks in priority areas of conservation, protecting either the species and key habitats for its survival.

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