21 research outputs found
Effets d’une attaque de tordeuse des bourgeons de l’épinette sur l’exportation d’éléments au-dessous de la zone racinaire : une étude de cas dans une forêt de sapins baumiers
Diferenças nas propriedades adesivas de Staphylococcus saprophyticus a células HEp-2 e eritrócitos
Modelling critical loads for the Solling spruce site
Critical loads were assessed with a steady-state soil model, a dynamic soil model, and an integrated forest-soil model, using data from the Solling spruce site. The critical loads of sulphur obtained with the dynamic and integrated models are close (within 30%) to the steady-state model calculations. For nitrogen, the spread in the model results is wider owing to the very different criteria (soil solution chemistry versus forest vitality) used for deriving the critical loads. The agreement lends confidence to the simplified critical-load calculations carried out on a European scale
Genetic association analysis of 13 nuclear-encoded mitochondrial candidate genes with type II diabetes mellitus: the DAMAGE study
Profiles of isoprene emission and photosynthetic parameters in hybrid poplars exposed to free-air CO2 enrichment+
Sampling strategies for tropical forest nutrient cycling studies: a case study in São Paulo, Brazil
Species-level effects more important than functional group-level responses to elevated CO2: evidence from simulated turves
Using mixtures of 14 calcareous grassland plant species drawn from three functional groups, we looked at the effects of elevated atmospheric CO2 on contrasting levels of ecosystem performance (species, functional group and community). Experimental communities were subjected to ambient (?350 µmol mol?1) or elevated CO2 (?600 µmol mol?1) in controlled environments, with grazing simulated by clipping at monthly intervals for 546 days.We assessed the effect of elevated CO2 on plant performance by quantifying the productivity (biomass) and cover of component species. We also examined the effect of elevated CO2 on the vertical structure of the plant canopy. Elevated CO2 resulted in a significant increase in total community biomass only following nutrient addition. Within functional groups, non-leguminous forb species had significantly greater biomass and cover in elevated CO2 both before and after nutrient addition, although the effect was mainly due to the influence of one species (Centaurea nigra). Grasses, in contrast, responded negatively to elevated CO2, although again significant reductions in biomass and cover could mainly be ascribed to a single species (Brachypodium pinnatum). Legumes exhibited increased biomass and cover in elevated CO2 (the effects being particularly marked for Anthyllis vulneraria and Lotus corniculatus), but this response disappeared following nutrient addition. Vertical structure was little affected by CO2 treatment.We conclude that due to the idiosyncratic responses of individual species, the categorization of plants into broad functional groups is of limited use in guiding our understanding of the impacts of elevated atmospheric CO2 on plant communities.<br/