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Soil methane oxidation in both dry and wet temperate eucalypt forests shows a near-identical relationship with soil air-filled porosity
Citation
Fest, BJ and Hinko-Najera, N and Wardlaw, TJ and Griffith, DWT and Livesley, SJ and Arndt, SK, Soil methane oxidation in both dry and wet temperate eucalypt forests shows a near-identical relationship with soil air-filled porosity, Biogeoscience, 14, (2) pp. 467-479. ISSN 1726-4170 (2017) [Refereed Article]
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Copyright Statement
Copyright 2017 the Authors. Licensed under Creative Commons Attribution 3.0 (CC BY 3.0) https://creativecommons.org/licenses/by/3.0/
DOI: doi:10.5194/bg-14-467-2017
Abstract
Well-drained, aerated soils are important sinks for
atmospheric methane (CH4) via the process of CH4 oxidation
by methane-oxidising bacteria (MOB). This terrestrial
CH4 sink may contribute towards climate change mitigation,
but the impact of changing soil moisture and temperature
regimes on CH4 uptake is not well understood in
all ecosystems. Soils in temperate forest ecosystems are the
greatest terrestrial CH4 sink globally. Under predicted climate
change scenarios, temperate eucalypt forests in southeastern
Australia are predicted to experience rapid and extreme
changes in rainfall patterns, temperatures and wild
fires. To investigate the influence of environmental drivers
on seasonal and inter-annual variation of soil–atmosphere
CH4 exchange, we measured soil–atmosphere CH4 exchange
at high-temporal resolution (< 2 h) in a dry temperate eucalypt
forest in Victoria (Wombat State Forest, precipitation
870 mm yr−1
) and in a wet temperature eucalypt forest
in Tasmania (Warra Long-Term Ecological Research
site, 1700 mm yr−1
). Both forest soil systems were continuous
CH4 sinks of −1.79 kg CH4 ha−1 yr−1
in Victoria
and −3.83 kg CH4 ha−1 yr−1
in Tasmania. Soil CH4 uptake
showed substantial temporal variation and was strongly controlled
by soil moisture at both forest sites. Soil CH4 uptake
increased when soil moisture decreased and this relationship
explained up to 90 % of the temporal variability. Furthermore,
the relationship between soil moisture and soil CH4
flux was near-identical at both forest sites when soil moisture
was expressed as soil air-filled porosity (AFP). Soil temperature
only had a minor influence on soil CH4 uptake. Soil nitrogen
concentrations were generally low and fluctuations in
nitrogen availability did not influence soil CH4 uptake at either
forest site. Our data suggest that soil MOB activity in the
two forests was similar and that differences in soil CH4 exchange
between the two forests were related to differences in
soil moisture and thereby soil gas diffusivity. The differences
between forest sites and the variation in soil CH4 exchange
over time could be explained by soil AFP as an indicator of
soil moisture status.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | soil, methane oxidation, Eucalyptus, soil air-filled porosity |
| Research Division: | Agricultural, Veterinary and Food Sciences |
| Research Group: | Forestry sciences |
| Research Field: | Forestry sciences not elsewhere classified |
| Objective Division: | Environmental Policy, Climate Change and Natural Hazards |
| Objective Group: | Mitigation of climate change |
| Objective Field: | Management of greenhouse gas emissions from plant production |
| UTAS Author: | Wardlaw, TJ (Dr Timothy Wardlaw) |
| ID Code: | 122613 |
| Year Published: | 2017 |
| Web of Science® Times Cited: | 14 |
| Deposited By: | Office of the School of Biological Sciences |
| Deposited On: | 2017-11-21 |
| Last Modified: | 2018-01-08 |
| Downloads: | 134 View Download Statistics |
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