Effects of soil moisture content and temperature on methane uptake by grasslands on sandy soils

• Published in: Plant and soil 1998-07, Vol.204 (2), p.213-222
• Main Authors: Pol-van Dasselaar, A. van den, Beusichem, M.L. van, Oenema, O
• Format: Article
• Language: English
• Subjects: ABSORCION DE SUSTANCIAS NUTRITIVAS; ABSORPTION DE SUBSTANCES NUTRITIVES; AEROBIOSE; AEROBIOSIS; Agronomy. Soil science and plant productions; Atmospheric methane; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Climate change; CONTENIDO DE AGUA EN EL SUELO; Evapotranspiration; Forest soils; Fundamental and applied biological sciences. Psychology; Grassland soils; GRASSLANDS; HERBAGE; Instituut voor Agrobiologisch en Bodemvruchtbaarheidsonderzoek; METANO; METHANE; Microbiology; Moisture content; NUTRIENT UPTAKE; Oxidation; PE&RC; Physics, chemistry, biochemistry and biology of agricultural and forest soils; PRADERAS; Research Institute for Agrobiology and Soil Fertility; SANDY SOILS; Sectie Bodemkwaliteit; Soil air; Soil moisture; Soil science; SOIL TEMPERATURE; Soil temperature regimes; Soil water; SOIL WATER CONTENT; Soils; SOL SABLEUX; Spatial variability; Sub-department of Soil Quality; SUELO ARENOSO; TEMPERATURA DEL SUELO; TEMPERATURE DU SOL; TENEUR EN EAU DU SOL; Variability; Water stress
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1023/A:1004371309361

Aerobic grasslands may consume significant amounts of atmospheric methane (CH₄). We aimed (i) to assess the spatial and temporal variability of net CH₄ fluxes from grasslands on aerobic sandy soils, and (ii) to explain the variability in net CH₄ fluxes by differences in soil moisture content and temperature. Net CH₄ fluxes were measured with vented closed flux chambers at two sites with low N input on sandy soils in the Netherlands: (i) Wolfheze, a heather grassland, and (ii) Bovenbuurtse Weilanden, a grassland which is mown twice a year. Spatial variability of net CH₄ fluxes was analysed using geostatistics. In incubation experiments, the effects of soil moisture content and temperature on CH₄ uptake capacity were assessed. Temporal variability of net CH₄ fluxes at Wolfheze was related to differences in soil temperature (r² of 0.57) and soil moisture content (r² of 0.73). Atmospheric CH₄ uptake was highest at high soil temperatures and intermediate soil moisture contents. Spatial variability of net CH₄ fluxes was high, both at Wolfheze and at Bovenbuurtse Weilanden. Incubation experiments showed that, at soil moisture contents lower than 5% (w/w), CH₄ uptake was completely inhibited, probably due to physiological water stress of methanotrophs. At soil moisture contents higher than 50% (w/w), CH₄ uptake was greatly reduced, probably due to the slow down of diffusive CH₄ and O₂ transport in the soil, which may have resulted in reduced CH₄ oxidation and possibly some CH₄ production. Optimum soil moisture contents for CH₄ uptake were in the range of 20 - 35% (w/w), as prevailing in the field. The sensitivity of CH₄ uptake to soil moisture content may result in short-term variability of net atmospheric CH₄ uptake in response to precipitation and evapotranspiration, as well as in long-term variability due to changing precipitation patterns as a result of climate change.