Temperate forest methane sink diminished by tree emissions

Journal Article · Fri Mar 31 00:00:00 EDT 2017 · New Phytologist

DOI:https://doi.org/10.1111/nph.14559· OSTI ID:1401529

Pitz, Scott ^[1]; Megonigal, J. Patrick ^[2]

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1. Department of Earth and Planetary Sciences Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA, Smithsonian Environmental Research Center 647 Contees Wharf Road Edgewater MD 21037 USA
2. Smithsonian Environmental Research Center 647 Contees Wharf Road Edgewater MD 21037 USA

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.

• Sponsoring Organization: USDOE
• Grant/Contract Number: DE‐SC0008165; SC0008165
• OSTI ID: 1401529
• Journal Information: New Phytologist, Journal Name: New Phytologist Vol. 214 Journal Issue: 4; ISSN 0028-646X
• Publisher: Wiley-Blackwell
• Country of Publication: United Kingdom
• Language: English