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| Silva,Igor Aurélio; Cianciaruso,Marcus Vinicius; Batalha,Marco Antônio. |
| We examined the species abundance distribution (SAD) of plant communities in: (1) a wet grassland, waterlogged throughout most of the year; (2) a seasonal savanna, with an annual dry season; and (3) a hyperseasonal savanna, with alternating drought and waterlogging over the year. We searched for differences in the abundance distributions of all species, as well as of the common and rare species. We tested whether the SADs fitted the lognormal, log-series, power fraction, and random assortment models. We found that environmental constraints may reduce the evenness of plant communities and change the SADs in savannas. We observed a lognormal abundance distribution in the wet grassland and a random abundance distribution in the hyperseasonal cerrado. The SAD... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Assembly rules; Cerrado; Environmental filter; Evenness; Relative abundance distribution. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062010000200011 |
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| Gauthier, Olivier; Sarrazin, Jozee; Desbruyeres, Daniel. |
| Our knowledge of species diversity in deep-sea chemosynthetic communities has come a long way since their discovery in the late 1970s, However, their study poses serious challenges that are linked to their remoteness, the variable selectivity and effectiveness of sampling tools in different conditions, a lack of consensus on the size compartments and sieve size used in practice, and the persistent discovery of species that are previously unknown to science. Still, with increasing accessibility and new sampling tools, quantitative data are becoming both more frequent and extensive, reducing limitations in the estimation and comparison of species diversity. Here, we review the literature for common difficulties encountered in the measurement and comparison... |
| Tipo: Text |
Palavras-chave: Deep-sea ecosystems; Chemosynthetic community; Species diversity; Richness; Evenness; Rarefaction; Diversity profiles; Diversity ordering; Alpha diversity; Statistical analysis. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11274/7842.pdf |
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