8,941 research outputs found
The magnitude and extent of edge effects on vascular epiphytes across the Brazilian Atlantic Forest
Edge effects are ubiquitous landscape processes influencing over 70% of forest cover worldwide. However, little is known about how edge effects influence the vertical stratification of communities in forest fragments. We combined a spatially implicit and a spatially explicit approach to quantify the magnitude and extent of edge effects on canopy and understorey epiphytic plants in the Brazilian Atlantic Forest. Within the human-modified landscape, species richness, species abundance and community composition remained practically unchanged along the interior-edge gradient, pointing to severe biotic homogenisation at all strata. This is because the extent of edge effects reached at least 500 m, potentially leaving just 0.24% of the studied landscape unaffected by edges. We extrapolated our findings to the entire Atlantic Forest and found that just 19.4% of the total existing area is likely unaffected by edge effects and provide suitable habitat conditions for forest-dependent epiphytes. Our results suggest that the resources provided by the current forest cover might be insufficient to support the future of epiphyte communities. Preserving large continuous ‘intact’ forests is probably the only effective conservation strategy for vascular epiphytes
Efeito do pH na sÃntese de uma dispersão coloidal de nanopartÃculas de prata utilizando o ácido cÃtrico como agente redutor.
Nutrição de caprinos e ovinos em pastejo.
Exigências nutricionais de caprinos e ovinos em pastejo, Seleção de dietas, fatores morfológicos que interferem na seleção de dietas, volume rumino-reticular, tamanho da boca, correlação entre parâmetros, o manejo das pastagens, sistemas de pastejo, suplementação a pasto
Phase transformation in titania nanocrystals by the oriented attachment mechanism: the role of pH medium.
Pau-rosa - Aniba rosaeodora Ducke.
Pau-rosa: distribuição geográfica; variabilidade, silvicultura, produtividade no Estado do Amazonas (Brasil).bitstream/CPAA-2009-09/4322/1/Folder_Pau-rosa.pd
Susceptibility Amplitude Ratios Near a Lifshitz Point
The susceptibility amplitude ratio in the neighborhood of a uniaxial Lifshitz
point is calculated at one-loop level using field-theoretic and
-expansion methods. We use the Schwinger parametrization of the
propagator in order to split the quadratic and quartic part of the momenta, as
well as a new special symmetry point suitable for renormalization purposes. For
a cubic lattice (d = 3), we find the result .Comment: 7 pages, late
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