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131.
Altough peatlands in southern Québec are facing increasing pressure, neither specific nor substantial protection measures have been implemented, partly due to a lack of information on this ecosystem. We determined the contribution of peatlands to bird regional diversity by measuring the difference between peatland and associated regional avifaunas. We sampled 112 peatlands located along the Saint Lawrence River during one breeding season. We used data on regional nesting bird assemblages from the Québec breeding bird atlas. Peatland bird species contrasted increasingly with regional avifauna from north to south or from undisturbed to managed landscapes. Of the 17 bird species found significantly more often in peatlands than in surroundings, some preferred peatlands in the whole study area and others preferred peatlands only in particular regions. Peatland avifaunas within regions were more similar to each other than to their regional avifauna, and differences between regions probably reflected changes in peatland physiognomy. We conclude that peatlands contribute to enrich local and regional avian diversity, particularly in the lowlands of the Saint Lawrence River, where industrial pressure on peatlands is highest. 相似文献
132.
Amaranthus tricolor is a potential accumulator of nitrate but nutrient sufficiency guidelines have not been developed for this vegetable. We investigated whether the shoot stem of A. tricolor is a suitable index for crop nitrate status, and whether freezing the stem, which aids sap extraction, would render it unsuitable for the analysis of nitrate and other nutrients. We grew A. tricolor at two nitrogen (N) rates (100 and 200 mg L?1 as nitrate-N) and established that sap nitrate from both fresh and frozen-thawed stems did not differ but was significantly increased by additional N fertilizer. Shoot growth was correspondingly higher with additional N. Therefore, the stem is a suitable index for crop nitrate. Boron (B), calcium (Ca), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na) and sulfur (S) were significantly affected by frozen storage but potassium (K), phosphorus (P) and zinc (Zn) were not. A single sufficiency guideline is possible for these nutrients, for use with both fresh and frozen-thawed stem sap. 相似文献
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134.
BACKGROUND: Turfgrass management practices, especially the use of chemical pesticides, may be detrimental to beneficial arthropods such as predators and decomposers. However, little is known about the impact of other practices or pest control products on these beneficials. The impact of four different management regimes, consisting of synthetic pesticide cover sprays or combinations of more targeted applications of natural pesticides, on selected groups of non‐targeted arthropods in lawns of different age was studied over 3 years. The short‐term effect of diazinon and carbaryl on Carabidae and Collembola was also evaluated. RESULTS: Formicidae and Araneae were the most abundant taxa at both sites, representing 74–80% of total captures. With a few short‐term exceptions, no persistent and significant difference between turfgrass management regimes on arthropod abundance was observed over the 3 year study. Diazinon and carbaryl significantly reduced Carabidae abundance, but only one year out of three, while Collembola abundance was only transiently affected by carbaryl application in 2003. CONCLUSION: The study showed that practices and products used in the four management regimes did not disrupt the populations of specific groups of arthropods. These results provide useful information to professionals for the development of ecological turf practices to maintain beneficial arthropod abundance and diversity in urban landscapes. Copyright © 2012 Society of Chemical Industry 相似文献
135.
Anne‐Sophie Walker Annie Micoud Florent Rémuson Jacques Grosman Michel Gredt Pierre Leroux 《Pest management science》2013,69(6):667-678
Resistance to fungicides is an evolutionary process resulting from the selection of advantageous genotypes in naturally diverse populations. Seven fungicide modes of action are authorised to control grey mould caused by Botrytis cinerea on grapevine in France, and five of them have encountered specific resistance, with variable frequencies in populations and possible consequences for field fungicide efficacy. Moreover, multidrug resistance is caused by fungicide efflux and allows a weak resistance towards six unrelated modes of action. Here, a review is given of the fungicide resistance status of B. cinerea in France, particularly in the vineyards of Champagne, which are the most affected. Recently developed resistance and recent findings concerning the associated resistance mechanisms are focused upon in particular. Finally, antiresistance strategies are presented, and examples of managed resistance are discussed in a more general manner with the aim of extending this knowledge to other crops and countries undergoing similar resistance problems. © 2013 Society of Chemical Industry 相似文献
136.
Pascal-Lorber S Despoux S Jamin EL Canlet C Cravedi JP Laurent F 《Journal of agricultural and food chemistry》2012,60(7):1728-1736
This study compared the metabolic fate of [(14)C]-DCP, [(14)C]-residues from radish plants, and purified [(14)C]-DCP-(acetyl)glucose following oral administration in rats. A rapid excretion of radioactivity in urine occurred for [(14)C]-DCP, [(14)C]-DCP-(acetyl)glucose, and soluble residues, 69, 85, and 69% within 48 h, respectively. Radio-HPLC profiles of 0-24 h urine from rats fed [(14)C]-DCP and [(14)C]-DCP-(acetyl)glucose were close and qualitatively similar to those obtained from plant residues. No trace of native plant residues was detected under the study conditions. The structures of the two major peaks were identified by MS as the glucuronide and the sulfate conjugates of DCP. The characterization of a dehydrated glucuronide conjugate by MS and NMR of DCP was unusual. In contrast to soluble residues, bound residues were mainly excreted in feces, 90% within 48 h, whereas total residues were eliminated in both urine and feces. For total residues, the radioactivity in feces was higher than expected from the percentage of soluble and bound residues in radish plants. This result highlighted that less absorption took place when residues were present in the plant matrix as compared to plant-free residues and DCP. 相似文献
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138.
Oldrich Navratil Olivier Evrard Michel Esteves Sophie Ayrault Irène Lefèvre Cédric Legout Jean-Louis Reyss Nicolas Gratiot Julien Nemery Nicolle Mathys Alain Poirel Philippe Bonté 《Journal of Soils and Sediments》2012,12(9):1463-1478
Purpose
Quantifying suspended sediment fluxes and dynamics across mountains, and identifying the origin of sediment in severely eroded areas, are of primary importance for the management of water resources. This contribution aims to generalise previous results from suspended sediment fingerprinting obtained during 2007?C2009 in a mesoscale Alpine catchment (the Bléone River; 905?km2) in France, and to assess variability in sediment sources throughout the second half of the twentieth century.Materials and methods
Sediment fingerprinting, based on elemental geochemistry and radionuclide measurements, was conducted on a sediment core collected in an alluvial floodplain at the basin outlet. This technique was combined with hydro-sedimentary time-series to reconstruct the origin of suspended sediment deposited at this location over the last 50?years.Results and discussion
Interpretation of sedimentation based on historical hydrological databases corroborates core dating obtained with 137Cs and 210Pbxs activity measurements. Black marls and (marly) limestone sources provided the main fraction of sediment throughout the sequence (40 and 22?%, respectively). However, we also found evidence for the occurrence of major floods carrying large quantities of sediment originating from Quaternary deposits and conglomerates (25 and 16?%, respectively). The variability of sediment sources throughout the sequence may reflect the spatial variability of rainfall within the catchment, which in turn reflects its origin. However, the relatively homogeneous sediment composition throughout the sequence confirms that core-derived information is representative of widespread flood events.Conclusions
These results are consistent with those obtained in previous studies. They also outline the need to take into account the entire grain size range of fine sediment in order to provide an overall picture of sediment sources and transfers within highly erosive catchments. This study also emphasizes the importance of using archival data to validate the results of sediment fingerprinting studies conducted during short contemporary monitoring programmes, and to extend fingerprinting of sediment sources over longer time-scales which include large and widespread floods. 相似文献139.
140.
Nogueira SA Torres SM Malone ED Diaz SF Jessen C Gilbert S 《Veterinary dermatology》2006,17(4):259-265
Imiquimod is an immune response modifier with potent antiviral and antitumour activity. The objective of this pilot study was to evaluate the efficacy of an imiquimod 5% cream (Aldaratrade mark: 3M, Saint Paul, MN, USA) as a topical treatment for equine sarcoids. Fifteen horses with a total of 19 tumours were enrolled, including mixed (7), fibroblastic (5), flat (3), verrucous (2), and nodular (2) types. Baseline data included history, physical examination, tumour location, measurement and digital photography. Imiquimod was applied by the owners three times a week until complete resolution of the tumour or 32 weeks, whichever occurred first. Tumours were measured and photographed every 4 weeks. Treatment efficacy was defined as 75% or greater reduction of tumour size by the end of the trial. Four sarcoids were withdrawn from the study. Twelve of the remaining 15 tumours (80%) showed more than 75% reduction in size and nine (60%) totally resolved between 8 and 32 weeks. The most common adverse effects of exudation, erythema, erosions, depigmentation and alopecia were limited to the tumour and adjacent areas. The results suggest that topical imiquimod is a therapeutic option for the treatment of equine sarcoids, although more detailed studies are required to corroborate these initial findings. 相似文献