Environmental Correlation and Spatial Autocorrelation of Soil Properties in Keller Peninsula, Maritime Antarctica

André Geraldo De Lima Moraes,Marcos Gervasio Pereira,Waldir De Carvalho Junior,Marcio Rocha Francelino,André Thomazini,Carlos Ernesto Gonçalves Reynaud Schaefer

doi:10.1590/18069657rbcs20170021

Abstract

The pattern of variation in soil and landform properties in relation to environmental covariates are closely related to soil type distribution. The aim of this study was to apply digital soil mapping techniques to analysis of the pattern of soil property variation in relation to environmental covariates under periglacial conditions at Keller Peninsula, Maritime Antarctica. We considered the hypothesis that covariates normally used for environmental correlation elsewhere can be adequately employed in periglacial areas in Maritime Antarctica. For that purpose, 138 soil samples from 47 soil sites were collected for analysis of soil chemical and physical properties. We tested the correlation between soil properties (clay, potassium, sand, organic carbon, and pH) and environmental covariates. The environmental covariates selected were correlated with soil properties according to the terrain attributes of the digital elevation model (DEM). The models evaluated were linear regression, ordinary kriging, and regression kriging. The best performance was obtained using normalized height as a covariate, with an R2 of 0.59 for sand. In contrast, the lowest R2 of 0.15 was obtained for organic carbon, also using the regression kriging method. Overall, results indicate that, despite the predominant periglacial conditions, the environmental covariates normally used for digital terrain mapping of soil properties worldwide can be successfully employed for understanding the main variations in soil properties and soil-forming factors in this region. Keywords: kriging, geostatistical methods, soil variability.

Highlights

Antarctica, which is the coldest continent, has unique climatic and weathering conditions that lead to unique soil formation in ice-free areas at very slow rates (Simas et al, 2008)
In comparison with continental Antarctica, the Maritime region has higher temperature and precipitation rates, contributing to greater colonization of plant species and soil microorganisms, which favors a higher degree of weathering (Pereira and Putzke, 2013). These factors are frequently associated with terrestrial input of nutrients by marine birds, which are highly important for soil-forming processes in Antarctica, enhancing pedogenesis through the phosphatization process and forming widespread ornithogenic soils (Simas et al, 2008)
The aim of this study was to apply digital soil mapping techniques to analyze the pattern of variation of soil properties in relation to environmental covariates under periglacial conditions at Keller Peninsula, Maritime Antarctica

Summary

Introduction

Antarctica, which is the coldest continent, has unique climatic and weathering conditions that lead to unique soil formation in ice-free areas at very slow rates (Simas et al, 2008). In comparison with continental Antarctica, the Maritime region has higher temperature and precipitation rates, contributing to greater colonization of plant species and soil microorganisms, which favors a higher degree of weathering (Pereira and Putzke, 2013). These factors are frequently associated with terrestrial input of nutrients by marine birds (guano), which are highly important for soil-forming processes in Antarctica, enhancing pedogenesis through the phosphatization process and forming widespread ornithogenic soils (Simas et al, 2008). Antarctic soils have been the subject of several studies (Beyer et al, 2000; Simas et al, 2008; Francelino et al, 2011; Moura et al, 2012) that have promoted an increasing understanding of soil-forming processes and soil distribution and classification

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