Mineralogical and chemical attributes of soils from the Brazilian Atlantic Forest domain

Abstract

The Atlantic Forest is one of the most important and yet the most devastated Brazilian biome, occupying in the past the majority of the East Atlantic Coast. Therefore, a detailed knowledge of the soils near the coastal line influenced by this biome is essential for land use and management of these environments. The aim of this study was to acquire a deeper knowledge of the chemistry, mineralogy and genesis of soils in two micro-watersheds of the Atlantic Forest Biome. Eight soil profiles were sampled and described along one transect. Both young and more developed soils exhibit low fertility and low Fe 2 O 3 content. The Oxic Dystrudepts are less dystrophic than the other soils studied and exhibit greater availability of K + , due to the mixing of weathered material and primary minerals. Transitions from shallow to deep soils are more common in rejuvenated landscapes. All soils are kaolinitic (Kt), with low levels of goethite (Gt) and hematite (Hm), and contain secondary 2:1 minerals such as mica (Mi) and, in the youngest soils, hydroxy-interlayered vermiculite (HIV) and interstratified mica-hydroxy-interlayered vermiculite (Mi-HIV). The widespread presence of gibbsite (Gb) in soils, including the Lithic Udifolist, indicates high rates of both pedogenesis and morphogenesis. The gibbsite showed good crystallinity suggesting that climate, terrain and good drainage favored its formation and stability.

Association of Post-Barreiras and Barreiras Formation strata and influence on soil genesis, Southern Bahia – Brazil

“…On the other hand, sandy clay sub-horizons have more crystallized kaolinite, and there is the presence of hematite, goethite, and gibbsite (P2 and P6). These minerals are common in Brazilian soils, including in Barreiras Formation environments (Moreau et al, 2006a;Cunha et al, 2019). The high regional rainfall also influences the low soil fertility because sandy soils have higher leaching (Rêgo et al, 2019) In the upper horizons, we verified the high presence of Na + , which is explained by the constant action of saline sprays of the coast (Magnago et al, 2013).…”

“…Also, by sedimentary deposition, forming the Post-Barreiras sediments (Tatumi et al, 2008;Rossetti et al, 2011;Gandini et al, 2014). In the literature, there are several pedological studies on sediments from the Barreiras Formation (Demattê et al, 1996;Moreau et al, 2006b;Cunha et al, 2019). However, studies with Post-Barreiras sediments do not focus on pedology.…”

Multifunctional soil recovery during the restoration of Brazil's Atlantic Forest after bauxite mining

“…The study area has an Oxic Dystrudept soil, which is characterized by an incipient B Horizon, clays with low cation exchange capacity and shallow depth (Staff, 2014). This soil type is commonly found in the Atlantic Forest (Cunha et al., 2019).…”

Recovery of soil phosphorus on former bauxite mines through tropical forest restoration

“…Selected sites presented an Oxic Dystrudept (Soil Survey Staff 2014), a soil type that is commonly found in hilly areas of the Atlantic Forest region and is characterized by an incipient B Horizon, low fertility, and shallow depth; salient rocks are commonly observed. The mineral composition of this soil type in another Atlantic Forest site (approximately 640 km apart) was kaolinite (490 g/kg), gibbsite (180 g/kg), goethite (2 g/kg), and mica (1 g/kg) (Cunha et al 2019).…”