7 documents found, page 1 of 1

Ocorrência e distribuição de pteridófitas na reserva florestal Walter Egler, Am...

Na Reserva Florestal Walter Egler, localizada a 64 km de Manaus, no município de Rio Preto da Eva, foi investigada a ocorrência de Pteridófitas ao longo de uma toposseqüência. O grupo ocorre nos três ambientes observados na área (baixio, vertente e platô) com diferença tanto qualitativa quanto quantitativa. Foram registrados 375 indivíduos, distribuídos em oito famílias, 10 gêneros e 17 espécies; entre epífitas...

Estimating the global conservation status of more than 15,000 Amazonian tree sp...

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red ...

Species Distribution Modelling: Contrasting presence-only models with plot abun...

Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on ...

Floristic composition and vegetation cover of the savannas in the "Alter do Chã...

In this study, we determined the floristic composition in 38 plots of 3.75 ha (250 m x 150 m) distributed throughout 30.000 ha of savannas of "Alter do Chão", Santarém Municipality. Our surveys revealed 130 species in 45 families. The only species of dicotoledons that covered 1% or more of the area in the herb-shrub layer were Dioclea bicolor Benth. and Lafoensia pacari A. St.-Hil. Most of the area was covered ...

Structure et dynamisme de la forêt

Résumé Les auteurs comparent la structure de la végétation de deux toposéquences choisies dans les bassins versants de la ZF-02. Pour ce faire, ils utilisent une méthode de description morpho-structurale de la végétation dont ils rappellent I'essentiel. Ils discutent des variations selon la position sur la toposéquence et de leurs causes. Ces résultats sont comparés à deux autres séquences. Répartition en class...

Disentangling structural patterns of natural forest fragments in a savanna matr...

Fragmentos naturais constituem importante fonte de recursos para o manejo e conservação da flora local. Este trabalho avaliou o efeito da fragmentação sobre a estrutura e a composição das comunidades de plantas de fragmentos florestais (FF), em Alter do Chão, na Amazônia oriental brasileira. Foram amostrados 25 sítios em FF e nove em floresta contínua (CF). Analisamos a diferença na densidade de plantas e na ri...

Composição florística e cobertura vegetal das savanas na região de Alter do Chã...