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1.
Forest management can seriously modify the biodiversity of forest dwelling species, but the consequences are poorly known for certain taxa, particularly soil fauna, for which few studies have been published. We compared the biodiversity of dictyostelids cellular slime moulds in a managed and an unmanaged forest in the French Alps and analysed the influence of environmental factors on species richness and abundance of dictyostelids. To our knowledge, this study is the first one undertaken in the European Alps. We must better understand the influence of various environmental factors on the biodiversity of these organisms if we want to accurately define their functional role in the soil. In our study, dictyostelids showed lower levels of diversity compared to previously published results. The mean species richness of dictyostelids was marginally higher in unmanaged than in managed forests and biodiversity indices were significantly correlated with elevation and pH. This suggests that environmental factors have a predominant effect on the biodiversity of dictyostelids and that the effect of forest management is secondary. 相似文献
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Maintenance and monitoring of soil fertility is a key issue for sustainable forest management. Vital ecosystem processes may
be affected by management practices which change the physical, chemical and biological properties of the soil. This study
is the first in Europe to use electrical resistivity (ER) as a non-invasive method to rapidly determine forest soil properties
in the field in a monitoring purpose. We explored the correlations between ER and forest soil properties on two permanent
plots of the French long-term forest ecosystem-monitoring network (International Cooperative Program Forests, Level II). We
used ER measurements to determine soil-sampling locations and define sampling design. Soil cores were taken in the A horizon
and analysed for pH, bulk density, residual humidity, texture, organic matter content and nutrients. Our results showed high
variability within the studied plots, both in ER and analysed soil properties. We found significant correlations between ER
and soil properties, notably cation exchange capacity, soil humidity and texture, even though the magnitude of the correlations
was modest. Despite these levels of correlations, we were able to assess variations in soil properties without having to chemically
analyse numerous samples. The sampling design based on an ER survey allowed us to map basic soil properties with a small number
of samples. 相似文献
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Dianne Baunbk Nolwenn Trinkler Yoan Ferandin Olivier Lozach Poonsakdi Ploypradith Somsak Rucirawat Fumito Ishibashi Masatomo Iwao Laurent Meijer 《Marine drugs》2008,6(4):514-527
Lamellarins, a family of hexacyclic pyrrole alkaloids originally isolated from marine invertebrates, display promising anti-tumor activity. They induce apoptotic cell death through multi-target mechanisms, including inhibition of topoisomerase I, interaction with DNA and direct effects on mitochondria. We here report that lamellarins inhibit several protein kinases relevant to cancer such as cyclin-dependent kinases, dual-specificity tyrosine phosphorylation activated kinase 1A, casein kinase 1, glycogen synthase kinase-3 and PIM-1. A good correlation is observed between the effects of lamellarins on protein kinases and their action on cell death, suggesting that inhibition of specific kinases may contribute to the cytotoxicity of lamellarins. Structure/activity relationship suggests several paths for the optimization of lamellarins as kinase inhibitors. 相似文献
4.
A quantitative assessment of the ecological value of sycamore maple habitats in the French Alps 总被引：1，自引：0，他引：1
Yoan Paillet Frédéric Archaux Vincent Breton Jean-Jacques Brun 《Annals of Forest Science》2008,65(7):713-713
5.
1. A total of 655 mule ducklings were produced in three hatches by artificial insemination of common duck females Brown Tsaiya and Pekin “Alienor” and of their 2 reciprocal crossbreds with Muscovy semen.
2. They were fed ad libitum until 6 weeks, then restricted to one meal per day until day 75 and afterwards preforce fed until day 84 and subsequently force fed by 2 crammers, twice a day, from the age of 85 d and for a maximum of 13 d.
3. Body weight at hatching, 28 d, 56 d, 75 d, 84 d and at slaughter, the number of force‐fed meals, the “paletot” weight, the fatty liver weight, the fat release rate after sterilisation of a 60 g portion of liver and the serous melting rate were measured individually.
4. Significant dam genotype and hatch effects were present for all traits. The crammer effect on force feeding traits was also significant. For mule ducks from Brown Tsaiya, Tsaiya X Pekin, Pekin X Tsaiya and Pekin dams respectively, mean body weight was 2356, 3219, 3137 and 3801 g at 12 weeks, “paletot” weight was 1585, 2111, 2110 and 2470 g, fatty liver weight was 441, 585, 563 and 641 g, fat release rate was 35·1, 40·5, 38·2 and 46·0%.
5. The estimated differences between Pekin and Tsaiya genetic effects in their mule progeny were significant and in favour of the Pekin, except for the number of force fed meals and for the serous melting rate. Grandmother genetic effects were not significant, but maternal heterosis h m was in general significant and favourable: it was 8·5% for birth weight, about 4% for growth traits and “paletot” weight, 6·2% for fatty liver weight and – 2·8% (not significant) for fat release rate. A crossbreeding system between a heavier Pekin breed and Tsaiya would be worth considering to improve the fatty liver production of mule ducks. 相似文献
6.
Minatchy Nathalie Marie-Magdeleine Carine Calif Valériuse Félicité Yoan Periacarpin Fred Deloumeau Christian Pommier Frederic Archimède Harry 《Tropical animal health and production》2020,52(2):583-589
Tropical Animal Health and Production - Intake, digestion and nitrogen retention were measured in fifteen 1-year-old Black Belly rams that had an average weight of 35.3... 相似文献
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8.
We have built a torsional pendulum based on an individual single-walled carbon nanotube, which is used as a torsional spring and mechanical support for the moving part. The moving part can be rotated by an electric field, resulting in large but fully elastic torsional deformations of the nanotube. As a result of the extremely small restoring force associated with the torsional deformation of a single molecule, unusually large oscillations are excited by the thermal energy of the pendulum. By diffraction analysis, we are able to determine the handedness of the molecule in our device. Mechanical devices with molecular-scale components are potential building blocks for nanoelectromechanical systems and may also serve as sensors or actuators. 相似文献
9.
Aurélie Vuidot Yoan Paillet Frédéric Archaux Frédéric Gosselin 《Biological conservation》2011,(1):441-450
Higher densities of tree microhabitats in unmanaged forests may explain biodiversity differences with managed forests. To better understand the determinants of this potential biodiversity indicator, we studied the influence of tree characteristics on a set of tree microhabitats (e.g. cavities, cracks, bark features) on 75 plots in managed and unmanaged French forests. We hypothesized that the number of different microhabitat types per tree and the occurrence of a given microhabitat type on a tree would be higher in unmanaged than in managed forests, and that this difference could be linked to individual tree characteristics: diameter, vitality and species. We show that unmanaged forests contained more trees likely to host microhabitats (i.e. large trees, snags) at the stand level. However, at the tree level, forest management did not influence microhabitats; only tree characteristics did: large trees and snags contained more microhabitats. The number and occurrence of microhabitats also varied with tree species: oaks and beech generally hosted more microhabitats, but occurrence of certain types of microhabitats was higher on fir and spruce. We conclude that, even though microhabitats are not equally distributed between managed and unmanaged forests, two trees with similar characteristics in similar site conditions have the same number and probability of occurrence of microhabitats, whatever the management type. In order to preserve biodiversity, foresters could reproduce unmanaged forest features in managed forests through the conservation of specific tree types (e.g. veteran trees, snags). Tree microhabitats could also be more often targeted in sustainable forest management monitoring. 相似文献
10.
Tropical mammals represent some of the most threatened species, but also the least known because they tend to be difficult to study. To objectively evaluate the conservation status of these species, standardized methods are urgently required. The sun bear Helarctos malayanus is a case in point: it is cryptic, difficult to detect and consequently classified on the IUCN Red List as Data Deficient, and the highest priority for bear conservation research. In this study, we apply a detection/non-detection sampling technique using camera trap data with environmental covariates to estimate sun bear occupancy from three tropical forest study areas with different levels of degradation and protection status in Sumatra. Sun bear detections, and encounter rates, were highest in one of the primary forest study areas, but sun bear occupancy was highest in the degraded forest study area. Whilst, sun bears were recorded at a greater proportion of camera placements in degraded forest, these records were often on only one occasion at each placement, which greatly increased the final occupancy estimate. Primary forests with their large fruiting trees undoubtedly represent good sun bear habitat, but our results indicate that degraded forest can also represent important habitat. These forests should therefore not be considered as having limited conservation value and assigned to other uses, such as oil palm production, as has previously happened in Sumatra. Estimating occupancy between years will yield information on the population trends of sun bears and other tropical mammals, which can be used to provide more reliable conservation assessments. 相似文献