Landscape and soil regionalization in southern Brazilian Amazon and contiguous areas: methodology and relevance for ecological studies

Abstract

Soils of a large tropical area with differentiated landscapes cannot be treated uniformly for ecological applications. We intend to develop a framework based on physiography that can be used in regional applications. The study region occupies more than 1.1 million km 2 and is located at the junction of the savanna region of Central Brazil and the Amazon forest.It includes a portion of the high sedimentary Central Brazil plateau and large areas of mostly peneplained crystalline shield on the border of the wide inner-Amazon low sedimentary plain.A first broad subdivision was made into landscape regions followed by a more detailed subdivision into soil regions. Mapping information was extracted from soil survey maps at scales of 1:250000-1:500000. Soil units were integrated within a homogenized legend using a set of selected attributes such as taxonomic term, the texture of the B horizon and the associated vegetation. For each region, a detailed inventory of the soil units with their area distribution was elaborated. Ten landscape regions and twenty-four soil regions were recognized and delineated.Soil cover of a region is normally characterized by a cluster composed of many soil units. Soil diversity is comparable in the landscape and the soil regions. Composition of the soil cover is quantitatively expressed in terms of area extension of the soil units. Such geographic divisions characterized by grouping soil units and their spatial estimates must be used for regional ecological applications.

Zamia brasiliensis, a new species of Zamia (Zamiaceae, Cycadales) from Mato Grosso and Rondônia, Brazil

“…Habitat, geology and soils:-Zamia brasiliensis occurs in various habitats within the transition zone between the Brazilian Cerrado and the Amazon forest in upland areas of northern Mato Grosso and Rondônia states (Rondônia and North Mato Grosso Uplands Landscape Region, sensu Volkoff et al (2012), including submontane dense and open ombrophilous forests, semideciduous and deciduous seasonal forests, and woodland savannas, also known as Cerradão (IBGE 2012).…”

“…The Cacoal (Rondônia) population studied occurred in a woodland savanna (cerradão) in an area of rolling hills characterized (Figs. 3c, 3d) by a lithology of basement rocks and Paleozoic sediments (Central Rondônia hills sensu Volkoff et al, 2012). The soil is a slightly acidic sandy clay loam (Table 1) with a rocky substratum consisting of arcosean sandstones and ortho-quartzites with lenses of coal and gypsum (Pimenta Bueno formation, CPRM 1999).…”

Consequences of soil attributes on the productivity and eucalypt drought response in two climate types in Brazil

“…Variation of wood productivity in the Eucalyptus grandis plantations, characterized in six soil classes, with total amplitude ranging from 26 to 52 m³ ha -1 yr -1 (2-fold), but in only one place (GONÇALVES et al, 2013). However, regional-scale studies addressing the soils and climate are still poorly studied and require further grounding by soil scientists (VOLKOFF et al, 2012) One of the efficient ways to reduce the cost of wood is to increase forest productivity, and one of the strategies to achieve this goal is to know the main environmental stresses to Eucalyptus that are factors that reduce productivity. Among these, two stand out due to their association with the new forest frontiers, namely: i) Water stress, mainly in the central-west, north, northeast, and part of southeastern Brazil; and ii) Thermal stress related to high temperatures (above 36 °C) in tropical Brazil, or at low temperatures (below 5 °C) in southern Brazil.…”

Spatial Analysis of the Drivers, Characteristics, and Effects of Forest Fragmentation

“…The elevation of each municipality is similar to ensure this has minimal effect on observed fragmentation. Figure 3 demonstrates a map of the forest cover types of both Mato Grosso and Rondônia [41].…”