Fluxes of CO 2 , CH 4 , and N 2 O in tundra-covered and Nothofagus forest soils in the Argentinian Patagonia.

Autor: Sá MMF; Brazilian Agricultural Research Corporation, Embrapa Agrobiology, Rodovia BR 465, km 7, 23891-000 Seropédica, RJ, Brazil., Schaefer CEGR; Department of Soils, Federal University of Viçosa-UFV, Avenida Peter Henry Rolfs s/n, 36570-000 Viçosa, MG, Brazil., Loureiro DC; Department of Agricultural Engineering, Federal University of Sergipe-UFS, Avenida Marechal Rondon s/n, 49100-000 São Cristóvão, SE, Brazil., Simas FNB; Department of Education, Federal University of Viçosa-UFV, Avenida Peter Henry Rolfs s/n, 36570-000 Viçosa, MG, Brazil., Alves BJR; Brazilian Agricultural Research Corporation, Embrapa Agrobiology, Rodovia BR 465, km 7, 23891-000 Seropédica, RJ, Brazil., de Sá Mendonça E; Department of Plant Production, Federal University of Espírito Santo-UFES, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil., de Figueiredo EB; Department of Rural Development - DDR, Federal University of São Carlos-UFSCAR, Rodovia Anhanguera, km 174 - SP-330, 13600-970 Araras, SP, Brazil., La Scala N Jr; Department of Exact Sciences, São Paulo State University-FCAV/UNESP, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884-900 Jaboticabal, SP, Brazil., Panosso AR; Department of Exact Sciences, São Paulo State University-FCAV/UNESP, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884-900 Jaboticabal, SP, Brazil. Electronic address: alan.panosso@unesp.br.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2019 Apr 01; Vol. 659, pp. 401-409. Date of Electronic Publication: 2018 Dec 22.
DOI: 10.1016/j.scitotenv.2018.12.328
Abstrakt: While most soils in periglacial environments present high fluxes of CO 2 (F CO2 ), CH 4 (F CH4 ), and N 2 O (F N2O ), few of them have a tendency to drain greenhouse gases from the atmosphere. This study aimed to assess greenhouse gas fluxes at different sub-Antarctic sites and time periods (at the beginning of thaw and height of summer). To investigate the time of year effect on greenhouse gas emissions, F CO2 , F CH4 , and F N2O were measured at two sites tundra-covered (Ti and Th) and Nothofagus forest soil (Nf) on Monte Martial, at the southernmost tip of South America, Tierra del Fuego, Argentina. F CO2 ranged from 96.33 to 225.72 μg CO 2 m -2  s -1 across all sites and periods, showing a positive correlation with soil temperature (Ts) (4.1 and 8.2 °C, respectively) (r 2  > 0.7; p < 0.05). The highest values of F CO2 were found at Ti and Th (728.2 and 662.64 μg CO 2 m -2  s -1 , respectively), which were related to higher temperatures (8.2 and 8.6 °C, respectively) when compared to those of Nf. For F CH4 , the capture (drain) occurred during both periods at Nf (-26 and -79 μg C-CH 4 m -2  h -1 ) as well as Ti and Th (-21 and 12 μg C-CH 4 m -2  h -1 , respectively). F N2O also presented low values during both periods and showed a tendency to drain N 2 O from the atmosphere, especially at Nf (-2 μg N-N 2 O m -2  h -1 ). In addition, F N2O was slightly positive for Ti and Th (0.3 and 0.55 μg N-N 2 O m -2  h -1 , respectively). Soil moisture did not show a correlation (p > 0.05) with the measured greenhouse gas fluxes. A scenario of increased temperatures might result in changes in the balance between the emissions and drains of these gases from soils, leading to higher emission values of CH 4 and N 2 O, especially for tundra covered soils (Ti and Th), where the highest average fluxes and thermohydric variations were observed over the year.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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