In:
Biogeosciences, Copernicus GmbH, Vol. 19, No. 22 ( 2022-11-17), p. 5187-5197
Abstract:
Abstract. Alpine peatlands are recognized as a major natural contributor to the
budgets of atmospheric methane (CH4) but as a weak nitrous oxide
(N2O) source. Anthropogenic activities and climate change have put
these fragile nitrogen (N)-limited peatlands under pressure by altering
water table (WT) levels and enhancing N deposition. The response of
greenhouse gas (GHG) emissions from these peatlands to these changes is
uncertain. To address this knowledge gap, we conducted a mesocosm experiment
in 2018 and 2019 investigating individual and interactive effects of three
WT levels (WT−30, 30 cm below soil surface; WT0, 0 cm at the soil
surface; WT10, 10 cm above soil surface) and multiple levels of N
deposition (0, 20, 40, 80 and 160 kgNha-1yr-1) on growing
season CH4 and N2O emissions in the Zoige alpine peatland,
Qinghai–Tibetan Plateau. We found that the elevated WT levels increased
CH4 emissions, while N deposition had nonlinear effects (with
stimulation at moderate levels but inhibition at higher levels). In
contrast no clear pattern of the effect of WT levels on the cumulative
N2O emissions was evident, while N deposition led to a consistent and
linear increase (emission factor: 2.3 %–2.8 %), and this was dependent
on the WT levels. Given the current N deposition in the Zoige alpine
peatland (1.08–17.81 kg N ha−1), our results suggested that
the CH4 and N2O emissions from the alpine peatlands could greatly
increase in response to the possible doubling N deposition in the future. We
believe that our results provide insights into how interactions between
climate change and human disturbance will alter CH4 and N2O
emissions from this globally important habitat.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-19-5187-2022
DOI:
10.5194/bg-19-5187-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2158181-2
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