Floristic, Structural and Phytogeographical Analysis of the Savannas of Humaitá (Amazonas)
1986; Elsevier BV; Volume: 178; Issue: 1 Linguagem: Inglês
10.1016/s0367-2530(17)30203-7
ISSN1618-0585
AutoresGerhard Gottsberger, Wilfried Morawetz,
Tópico(s)Botany, Ecology, and Taxonomy Studies
ResumoThe extensive Puciari-Humaitá savannas in the southern Amazon region were partly investigated in regard to its flora, physiognomy, soils and climate. They can be defined as open tree-woodland which is neither floristically nor ecologically a cerrado. A quantitative floristic analysis revealed ca. 100 species/ha, 40 of them woody and 10 arboreous. The vegetation is usually dominated by 1 to 3 tree species, e.g. Curatella americana and Physocalymma scaberrimum. A low degree of species diversity per genus and/or family is typical. Stronger floristic relations to the surrounding forests and relations to northern and southern savannas are evident. Some species are widespread and common neotropical savanna plants, some are local endemics. The structure of the vegetation is documented by profile diagrams and various quantitative data. Leaves of all trees have a very similar rough silicious surface; 79.5 % are mesophyllic, 18.6 % macrophyllic and 1.9 % microphyllic. The soils are extremely poor in nutrients, rich in exchangeable Al and ill-drained; they are probably mainly responsible for the permanence of the open savannas within the forest region. The climate is humid-tropical with a slightly pronounced dry season. The vegetation is interpreted partly as being an impoverished relic savanna from the former large and species rich, dry pleistocene Amazonian savannas.
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