Genesis and properties of wetland soils by VIS-NIR-SWIR as a technique for environmental monitoring.
Wetlands are important ecosystems characterized by redoximorphic environments producing typical soil forming processes and organic carbon accumulation. Assessments and management of these areas are dependent on knowledge about soil characteristics and variability. By reflectance spectroscopy, information about soils can be obtained since their spectral behaviors are directly related to their chemical, physical, and mineralogical properties reflecting the pedogenetic processes and environment conditions. Our aims were: (a) to characterize the main soil classes of wetlands regarding their spectral behaviors in VIS-NIR-SWIR (350-2500 nm) and relate them to pedogenesis and environmental conditions, (b) to determine spectral ranges (bands) with greater expression of the main soil properties, (c) to identify spectral variations and similarities between hydromorphic soils from wetlands and other soils under different moisture conditions, and (d) to propose spectral models to quantify some chemical and physical soil properties used as environmental quality indicators. Nine soil profiles from the Pantanal region (Mato Grosso State, Brazil) and one from the Serra do Espinhaço Meridional (Minas Gerais State, Brazil) were investigated. Spectral morphology interpretation allowed identifying horizon differences regarding shape, absorption features and reflectance intensity. Some pedogenetic processes of wetland soils related to organic carbon accumulation and oxide iron variation were identified by spectra. Principal Component Analysis allowed discriminating soils from wetland and outside this area (oxidic environment). Quantification of organic carbon was possible with R2of 0.90 and low error. Quantification of clay content was masked by soils with organic carbon content over 2% where it was not possible to quantify with high R2and low error both properties when dataset has soil samples with high organic carbon content. By reflectance spectroscopy, important characteristics of wetland soils can be identified and used to distinguish from soils of different environments at low costs, reduced time, and with environmental quality.
Department of Soil Science, College of Agriculture "Luiz de Queiroz", University of São Paulo, Pádua Dias Avenue, 11, CP 9, Piracicaba, SP, 13418-900, Brazil. Electronic address: jamdemat@usp.br.
José Alexandre Melo
JAM
Demattê
Institute of Agricultural Sciences, Federal University of Jequitinhonha and Mucuri Valleys - Campus Unaí, Vereador João Narciso Avenue, 1380, Unaí, MG, 38610-000, Brazil. Electronic address: ingrid.horak@ufvjm.edu.br.
Ingrid
I
Horák-Terra
Department of Soils and Rural Engineering, Center of Agricultural Science, Federal University of Paraíba - Campus II, Highway BR 079 Km 12, Areia, PB, 58397-000, Brazil. Electronic address: rmbeirigo@yahoo.com.br.
Raphael Moreira
RM
Beirigo
Center for Technological Development/Water Resources Engineering, Federal University of Pelotas - Campus Porto, Street Gomes Carneiro Street, 1, Center, Pelotas, RS, 96010-610, Brazil. Electronic address: fabricio.terra@ufpel.edu.br.
Fabrício da Silva
FDS
Terra
Department of Soil Science, College of Agriculture "Luiz de Queiroz", University of São Paulo, Pádua Dias Avenue, 11, CP 9, Piracicaba, SP, 13418-900, Brazil. Electronic address: karina.marques@usp.br.
Karina Patrícia Prazeres
KPP
Marques
Department of Soil Science, College of Agriculture "Luiz de Queiroz", University of São Paulo, Pádua Dias Avenue, 11, CP 9, Piracicaba, SP, 13418-900, Brazil. Electronic address: caio.fongaro@gmail.com.
Caio Troula
CT
Fongaro
Department of Forest Engineering, Federal University of Jequitinhonha and Mucuri Valleys, Campus JK, Highway MGT 367 - Km 583, nº 5000, Diamantina, MG, 39100-000, Brazil. Electronic address: alexandre.christo@ufvjm.edu.br.
Alexandre Christófaro
AC
Silva
Department of Soil Science, College of Agriculture "Luiz de Queiroz", University of São Paulo, Pádua Dias Avenue, 11, CP 9, Piracicaba, SP, 13418-900, Brazil. Electronic address: pvidal@usp.br.
Pablo
P
Vidal-Torrado
D001938:Brazil; D002244:Carbon; D004784:Environmental Monitoring; D012987:Soil; D053833:Wetlands
D012987:Soil; D002244:Carbon
Environment monitoring; Reflectance spectroscopy; Remote sensing; Soil characterization; Soil spectral behavior; Spectral morphology