Methanol and other VOC fluxes from a Danish beech forest during late springtime

• Published in: Biogeochemistry 2011-11, Vol.106 (3), p.337-355
• Main Authors: Schade, Gunnar W, Solomon, Sheena J, Dellwik, Ebba, Pilegaard, Kim, Ladstätter-Weissenmayer, Annette
• Format: Article
• Language: English
• Subjects: acetone; Ambient temperature; Animal and plant ecology; Animal, plant and microbial ecology; Biogeochemistry; Biogeosciences; Biological and medical sciences; Canopies; Coniferous forests; Coniferous trees; conifers; deciduous forests; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Ecosystems; Emission measurements; Environmental Chemistry; Exact sciences and technology; Fagus sylvatica subsp. sylvatica; Forest canopy; Forest ecosystems; Forest soils; Forests; Fundamental and applied biological sciences. Psychology; gas emissions; Geochemistry; laboratory experimentation; leaves; Life Sciences; Low temperature; Methanol; Mineral soils; Mixing ratios; Monoterpenes; monoterpenoids; Organic compounds; photosynthesis; Pollutant emissions; Sedimentation & deposition; Soil and rock geochemistry; Soil microorganisms; Soil moisture; Soil water; Soils; spectrometers; spring; stomata; Surficial geology; Synecology; Terrestrial ecosystems; VOCs; Volatile organic compounds
• ISSN: 0168-2563; 1573-515X
• DOI: 10.1007/s10533-010-9515-5

In-canopy mixing ratio gradients and above-canopy fluxes of several volatile organic compounds (VOCs) were measured using a commercial proton transfer reaction mass spectrometer (PTR-MS) in a European beech (Fagus sylvatica) forest in Denmark. Fluxes of methanol were bidirectional: Emission occurred during both day and night with highest fluxes (0.2 mg C m−2 h−1) during a warm period; deposition occurred dominantly at daytime. Confirming previous branch-level measurements on beech, the forest’s monoterpene emissions (0–0.5 mg C m−2 h−1), and in-canopy mixing ratios showed a diurnal cycle consistent with light-dependent emissions; a result contrasting temperature-only driven emissions of most conifer species. Also emitted was acetone, but only at ambient temperatures exceeding 20°C. Slow deposition dominated at lower temperatures. Our in-canopy gradient measurements contrast with earlier results from tropical and pine forest ecosystems in that they did not show this beech ecosystem to be a strong sink for oxygenated VOCs (OVOCs). Instead, their gradients were flat and only small deposition velocities (