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Temperate forest methane sink diminished by tree emissions
Author(s) -
Pitz Scott,
Megonigal J. Patrick
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14559
Subject(s) - soil water , temperate climate , environmental science , sink (geography) , methane , temperate forest , temperate rainforest , atmospheric methane , atmospheric sciences , growing season , agronomy , environmental chemistry , ecology , chemistry , soil science , ecosystem , biology , geology , geography , cartography
Summary Global budgets ascribe 4–10% of atmospheric methane ( CH 4 ) sinks to upland soils and have assumed until recently that soils are the sole surface for CH 4 exchange in upland forests. Here we report that CH 4 is emitted from the stems of dominant tree species in a temperate upland forest, measured using both the traditional static‐chamber method and a new high‐frequency, automated system. Tree emissions averaged across 68 observations on 17 trees from May to September were 1.59 ± 0.88 μmol CH 4 m −2 stem h −1 (mean ± 95% confidence interval ), while soils adjacent to the trees consumed atmospheric CH 4 at a rate of −4.52 ± 0.64 μmol CH 4 m −2 soil h −1 ( P < 0.0001). High‐frequency measurements revealed diurnal patterns in the rate of tree‐stem CH 4 emissions. A simple scaling exercise suggested that tree emissions offset 1–6% of the growing season soil CH 4 sink and may have briefly changed the forest to a net CH 4 source.