White sand vegetation in an Amazonian lowland under the perspective of a young geological history

Abstract

How to cite: rOSSEttI DF Et AL. 2019. White sand vegetation in an Amazonian lowland under the perspective of a young geological history. An Acad Bras Cienc 91: e20181337.

Geodiversity in the Amazon drainage basin

“…Geology also affects species diversity due to tectonic processes, as tectonic subsidence and the formations of faults cause topographic gradients influencing vegetation diversity and distribution patterns [138,139]. Topography and hydrology also affect species richness and composition [188], and river type has also been shown to influence species richness, as forests along blackwater rivers (called igapó) generally contain a higher number of species and a different species composition compared to whitewater forests (called várzea) [189]. Naturally, fish species distributions are also dependent on the water geochemical properties [28,190].…”

The specialized white-sand flora of the Uatumã Sustainable Development Reserve, central Amazon, Brazil

“…), a possible explanation for the comparatively high number of species may be due the low inclusion crite ria (dbh ≥2.5 cm and ≥1 cm, respectively) which allows sampling of small shrubs to large trees. Therefore, these methodological differences and further characteristics such as conservation status (Adeney et al 2009), distur bance history (Prance and Schubart 1977;Ferreira et al 2013), the geological origin (Rossetti et al 2012(Rossetti et al , 2019, and the size of the sampled campinarana, as well as the connectivity among patches (Fine et al 2010;Costa et al 2020), possibly interfere in the reported species richness.…”

“…In some areas, the podzolization process acts in the impoverishment of lateritic soils, with the leaching promoting a gradual loss of the clay frac tion, leaving primarily the sand fraction which gives the soil greater porosity and favors the migration of organic matter (Klinge 1965;Mendonça et al 2015). Other areas originate from the weathering of sandy rocks, such as sandstones (Rossetti et al 2012), or from reworking sedi ments originating from paleochannels or paleodunes of the Pleistocene-Holocene (Rossetti et al 2012(Rossetti et al , 2019.…”

“…The variation in species composition, structure, and diversity is mainly related to differences in the water table and soil texture, as well as nutritional changes in soils (Tiessen et al 1994;Coomes and Grubb 1996;Coomes 1997;Damasco et al 2013;Targhetta et al 2015;Demarchi et al 2018). However, other factors such as the geological origin (Rossetti et al 2019), fire (Adeney et al 2009), and pre-Columbian and recent anthropic distur bances (Prance and Schubart 1977;Ferreira et al 2013;McMichael 2021) can also play an important role.…”

The vascular epiphyte flora in a white-sand ecosystem of the Uatumã Sustainable Development Reserve, Central Amazon

“…The vegetation that develops on white-sand soils is known in Brazil as campinaranas, which are distributed over approximately 335,000 km 2 and cover about 5% of the Amazon region (Adeney et al 2016). The general characteristics of the campinaranas include sandy, acidic, nutrient-poor soils (podzols) and water saturation or even exposure of the water table during rainy periods, but with a water deficit in dry periods (Rossetti et al 2019;Capurucho et al 2020). These combined characteristics act as environmental filters (Fine and Kembel 2011;Costa et al 2020) which select plants with morphological, anatomical, and/or physiological adaptations, and, thus, there is a high number of endemic lineages and species (Fine et al 2010;Fine and Baraloto 2016;Guevara et al 2016;Capurucho et al 2020).…”