Characteristics of Soils in Highland Wetlands as a Subsidy to Identifying and Setting their Limits

Abstract

Palustrine areas and wetlands in particular are fragile ecosystems, with high biodiversity and high ecological productivity, and they provide benefits to society. The aim of this study was to describe and classify the main soils occurring in the wetlands of the Southern Plateau of Santa Catarina, and propose criteria for identification of hydromorphic environments as an aid in demarcation of their boundaries. Soils of four wetlands, in the municipalities of Bom Jardim da Serra, Bom Retiro, Lages, and Painel were described, collected, and taxonomically classified. A transection was demarcated in each one in which soils were analyzed in sites with different degrees of hydromorphism, corresponding to the inner, transition, and outer areas. In hydromorphic areas, the content of organic matter in the soil is higher than in non-hydromorphic areas, which influences the color and classification of the soils. In these soils, Aquents, Aquepts, and Histosols predominate, and Udepts predominate in the outer area. The drainage class and the higher chroma in the subsurface horizons of the Udepts indicate that they are outside the boundaries of the wetlands. The dark color in the surface horizons, along with the greyish colors, associated or not with the presence of mottling in the subsurface horizons, were the most obvious characteristics of a hydromorphic condition, indicating that the soil is located in the transitional and inner areas of the wetlands.

Spatial Variability of the Physicochemical Properties of Soils from Seasonally Flooded Forest Fragments on a Tropical Plain

“…Acidity may also be evidence of the oxidation and reduction of Fe under aerobic and anaerobic conditions, common in Ipucas, as described by Faulkner and Richardson [6] and Warmling et al [49]. According to these authors, ferrolysis involves soil acidification and destruction of clays under the influence of exchange reactions involving Fe in alternating cycles of oxidation (dry period) and reduction (flooding period).…”

“…ese acidic conditions may also be related to the insoluble byproducts generated from the OM decomposition and high concentrations of Al [53], which may have promoted a decrease in the availability of other minerals such as P, Ca, Mg, and K [54,55]. Fe and Mg are important elements in the formation of hydromorphic soils by ferrolysis [6,49]. e higher Fe concentrations in the surface layers and in the centre may be related to leaching by rainwater [56], which brings plinthite-rich materials from the uplifted edges of the plain, composed primarily of Petric Plinthosol on a lateritic iron crust (cangas), as discussed by Martins et al [14].…”

Ensino da bioética: avaliação de um objeto virtual de aprendizagem

“…It can be used in regular classes or integrated into different virtual learning environments, according to the teaching intentions of each lecturer. It aims, in the case of academic reading, to attain the levels of an authentic hermeneutic 36 . In the shape of a hypertext, it seeks to explore the complexity facing a linear organization of knowledge and to require the reader to utilize their base of knowledge 37 .…”