Ecosystem scale methane fluxes in a natural temperate bog-pine forest in southern Germany
Authors: Hommeltenberg J., Mauder M., Drösler M., Heidbach K., Werle P., Schmid H.P.
Autors Affiliation: Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research IMK-IFU, Kreuzeckbahnstrasse 19, Garmisch-Partenkirchen, 82467, Germany; Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2/I, Freising, 85354, Germany; University of Applied Sciences Weihenstephan-Triesdorf, Weihenstephaner Berg 4, Freising, 85354, Germany
Abstract: Methane (CH4) and carbon dioxide (CO2) exchange were investigated over 15 months above a natural bog-pine site in the pre-alpine region of southern Germany. The measurements indicate annual methane emissions of +5.3±0.34gCm-2a-1 and an annual CO2 uptake of -62±20gCm-2a-1, resulting in a global warming potential balance of -50±74g [CO2 eq.]m-2a-1. Air temperature was identified as the environmental parameter showing the highest correlation with methane production, except for periods with low water table (<-0.12m). Furthermore, we compared three different methane flux gap-filling methods: the mean daily variation approach (MDV), a look up table (LUT) with various control parameters and an exponential regression function between methane flux and air temperature (NLR). It turns out that the LUT provides the best result for the gap-filling of half-hourly CH4 fluxes for the present data. By increasing the number of parameters in the LUT, the CH4 flux prediction could be considerably improved. Except for dry periods, day to day variations could be reproduced very well by the NLR method, but results for sub-daily fluctuations were poor. The choice of gap-filling method affects the annual methane budget estimate by at most ±0.5gCm-2a-1, or about 10% of the annual flux.This study presents one of the first eddy covariance based annual methane- and CO2-exchange estimates over a natural bog-pine ecosystem outside the boreal zone. Journal/Review: AGRICULTURAL AND FOREST METEOROLOGY
Volume: 198 Pages from: 273 to: 284
More Information: We gratefully acknowledge the Thünen Institute (TI) for funding the project “Organic Soils”. The Schechenfilz site is additionally part of the TERENO and ICOS-ecosystems networks, funded, in part, by Bundesministerium für Bildung und Forschung (BMBF) and the Helmholtz Association . We thank Niko Rosskopf (Humboldt University Berlin, Faculty of Agriculture and Horticulture, Department of Crop and Animal Sciences), who provided his data of soil parameters, and Bärbel Tiemeyer and Michel Bechtold (Thünen Institute Braunschweig, Institute of Climate-Smart Agriculture) for running several mini-diver gauges to measure water table fluctuations at the site and providing their data. Thanks to Elisabeth Eckart for her field support. Access to the sites was made possible by the NORIS-estate and the District Government of Upper Bavaria. This paper is dedicated to the memory of Peter Werle, who led the KIT part of the Schechenfilz project until he tragically passed away in September 2013.KeyWords: bog; boreal forest; carbon dioxide; coniferous forest; ecosystem modeling; eddy covariance; gap dynamics; methane; peatland, GermanyDOI: 10.1016/j.agrformet.2014.08.017Citations: 31data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-01-16References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here