Fluxes of CO2, CH4, and N2O in tundra-covered and Nothofagus forest soils in the Argentinian Patagonia

Mariana Médice Firme Sá; Carlos Ernesto G R Schaefer; Diego C Loureiro; Felipe N B Simas; Bruno J R Alves; Eduardo de Sá Mendonça; Eduardo Barretto de Figueiredo; Newton La Scala Jr; Alan R Panosso

doi:10.1016/j.scitotenv.2018.12.328

Fluxes of CO₂, CH₄, and N₂O in tundra-covered and Nothofagus forest soils in the Argentinian Patagonia

Sci Total Environ. 2019 Apr 1:659:401-409. doi: 10.1016/j.scitotenv.2018.12.328. Epub 2018 Dec 22.

Authors

Mariana Médice Firme Sá¹, Carlos Ernesto G R Schaefer², Diego C Loureiro³, Felipe N B Simas⁴, Bruno J R Alves¹, Eduardo de Sá Mendonça⁵, Eduardo Barretto de Figueiredo⁶, Newton La Scala Jr⁷, Alan R Panosso⁸

Affiliations

¹ Brazilian Agricultural Research Corporation, Embrapa Agrobiology, Rodovia BR 465, km 7, 23891-000 Seropédica, RJ, Brazil.
² Department of Soils, Federal University of Viçosa-UFV, Avenida Peter Henry Rolfs s/n, 36570-000 Viçosa, MG, Brazil.
³ Department of Agricultural Engineering, Federal University of Sergipe-UFS, Avenida Marechal Rondon s/n, 49100-000 São Cristóvão, SE, Brazil.
⁴ Department of Education, Federal University of Viçosa-UFV, Avenida Peter Henry Rolfs s/n, 36570-000 Viçosa, MG, Brazil.
⁵ Department of Plant Production, Federal University of Espírito Santo-UFES, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil.
⁶ Department of Rural Development - DDR, Federal University of São Carlos-UFSCAR, Rodovia Anhanguera, km 174 - SP-330, 13600-970 Araras, SP, Brazil.
⁷ Department of Exact Sciences, São Paulo State University-FCAV/UNESP, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884-900 Jaboticabal, SP, Brazil.
⁸ 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.

PMID: 31096371
DOI: 10.1016/j.scitotenv.2018.12.328

Abstract

While most soils in periglacial environments present high fluxes of CO₂ (F_CO2), CH₄ (F_CH4), and N₂O (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 CO₂ m^-2 s^-1 across all sites and periods, showing a positive correlation with soil temperature (Ts) (4.1 and 8.2 °C, respectively) (r² > 0.7; p < 0.05). The highest values of F_CO2 were found at Ti and Th (728.2 and 662.64 μg CO₂ 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-CH₄ m^-2 h^-1) as well as Ti and Th (-21 and 12 μg C-CH₄ m^-2 h^-1, respectively). F_N2O also presented low values during both periods and showed a tendency to drain N₂O from the atmosphere, especially at Nf (-2 μg N-N₂O m^-2 h^-1). In addition, F_N2O was slightly positive for Ti and Th (0.3 and 0.55 μg N-N₂O 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 CH₄ and N₂O, especially for tundra covered soils (Ti and Th), where the highest average fluxes and thermohydric variations were observed over the year.

Keywords: Climate change; GHG emissions; Tierra del Fuego.