Processos pedogeomorfológicos em ambientes periglaciais: o fenômeno patterned groundna Antártica Marítima

Abstract

Patterned ground is a typical landform of periglacial environments. Physicochemical processes driven by freezing and thawing mechanisms are commonof these environments. The present study aimed to analyze soil-landform relationships and processes associated with patterned ground on Snow Island, Maritime Antarctica. Field descriptions were carried out in three areas with PG occurrence. The soils were classified according to the U.S. Soil Taxonomy. Morphological, physical and chemical analyzes were performed.Physical processes such as cryoclastyand cryoturbationwere identified. Marked differences were observed between the central zones and the edges of the circles of the patterned ground surfaces. Central zones show greater pedogenetic development and higher values of sum of bases (SB) and nutrients (K and P). The edges have twice as much coarse fraction (> 2 mm), being more colonized by vegetation and subjected to organic matter illuviation(podzolization).This microscale variation of processes that have adual character (pedogeomorphological) is relevant for a better understanding of Antarctic ecosystems, being of inestimable value for the study of the establishment of periglacial conditions and for monitoring possible alterations in the face of climate change scenarios.