The effect of extreme temperatures on soil organic matter decomposition from Atlantic oak forest ecosystems

Nieves Barros; José Antonio Rodríguez-Añon; Jorge Proupín; César Pérez-Cruzado

doi:10.1016/j.isci.2021.103527

The effect of extreme temperatures on soil organic matter decomposition from Atlantic oak forest ecosystems

iScience. 2021 Nov 27;24(12):103527. doi: 10.1016/j.isci.2021.103527. eCollection 2021 Dec 17.

Authors

Nieves Barros¹, José Antonio Rodríguez-Añon¹, Jorge Proupín¹, César Pérez-Cruzado²

Affiliations

¹ Department of Applied Physics, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
² Department of Crop Production and Engineering Projects, University of Santiago de Compostela, 27002 Lugo, Spain.

Abstract

This work designs a heatwave with a calorimeter to analyze the response of soils from oak forest ecosystems to increasing temperature from 20°C to 60°C and to cooling from 60°C to 20°C. Calorimetry measures the heat rate of the soil organic matter decomposition and the response to increasing and decreasing temperatures directly. It was applied to soil samples representing different soil horizons with organic matter at different degree of decomposition given by their heat of combustion, calculated by differential scanning calorimetry. Results showed temperature-dependent decomposition rates from 20°C to 40°C or 50°C typical for enzymatic activity. From 40°C to 60°C, changes in the rates are less predictable. Data analysis during cooling showed that all samples suffered losses of their enzymatic capacity and that only those with the heat of combustion values close to that of carbohydrates resisted the heat wave.

Keywords: Biogeoscience; Earth-surface processes; Global change; Soil science.