José-Luis Machado

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• We tested the hypothesis that biological trait-based plant functional groups provide sufficient differentiation of species to enable generalization about a variety of plant ecophysiological traits or responses to nitrogen (N). • Seedlings of 34 North American grassland and savanna species, representing 5 functional groups, were grown in a glasshouse in an(More)
The scaling of respiratory metabolism to body size in animals is considered to be a fundamental law of nature, and there is substantial evidence for an approximate (3/4)-power relation. Studies suggest that plant respiratory metabolism also scales as the (3/4)-power of mass, and that higher plant and animal scaling follow similar rules owing to the(More)
Using a database of 2510 measurements from 287 species, we assessed whether general relationships exist between mass-based dark respiration rate and nitrogen concentration for stems and roots, and if they do, whether they are similar to those for leaves. The results demonstrate strong respiration-nitrogen scaling relationships for all observations and for(More)
The ability to accurately estimate light levels in shaded environments is important for understanding plant adaptations to shade. This study evaluates the effectiveness of three rapid methods of estimating the long-term integrated percentage of above-canopy photosynthetic photon flux density (PPFD) in a deeply shaded conifer-dominated forest understory.(More)
1 Although it is well established that nitrogen and light play major roles in structuring plant communities across the landscape, it is not as clear how they structure communities within forest stands. Virtually nothing is known about within-stand structure of understorey communities of herbs and small shrubs in near-boreal forests. 2 We tested the(More)
Despite many studies of the percent loss of hydraulic conductivity in excised branches, there is doubt as to whether cutting stems in air introduces unnatural embolism into the xylem at the cut surface. To address this question, hydraulic conductivity was measured in seedlings of northern red oak (Quercus rubra L.) and rooted scions of eastern cottonwood(More)
We compared fruiting data derived simultaneously from fruit traps placed on the ground and from canopy-surveyed plots in a terra firme rain forest, Colombian Amazonia. Values derived from the canopy-surveyed plots were higher than fruit-trap estimates. Fruiting patterns obtained throughout both methods were not correlated. Our results showed that the(More)
ATLAS has been successfully collecting 7 TeV pp collision data from the LHC since 2010, at a rate that will ultimately reach 40 MHz for nominal LHC conditions. The ATLAS trigger system, organized in three levels, handles this enormous data flow, providing efficient rejection by reconstructing and selecting high transverse momentum objects and reducing the(More)
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