Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Global Change Biology 23 (2017): 3403-3417, doi:10.1111/gcb.13620.
Description:
Extreme precipitation is predicted to be more frequent and intense accompanying global
warming, and may have profound impacts on soil respiration (Rs) and its components, i.e.,
autotrophic (Ra) and heterotrophic (Rh) respiration. However, how natural extreme rainfall or
snowfall events affect these fluxes are still lacking, especially under nitrogen (N) fertilization.
In this study, extreme rainfall and snowfall events occurred during a 3-year field experiment,
allowing us to examine their effects on the response of Rs, Rh and Ra to N supply. In normal
rainfall years of 2011/2012 and 2012/2013, N fertilization significantly stimulated Rs by 23.9%
and 10.9%, respectively. This stimulation was mainly due to the increase of Ra because of
N-induced increase in plant biomass. In the record wet year of 2013/2014, however, Rs was
independent on N supply because of the inhibition effect of the extreme rainfall event.
Compared with those in other years, Rh and Ra were reduced by 36.8% and 59.1%,
respectively, which were likely related to the anoxic stress on soil microbes and decreased
photosynthates supply. Although N supply did not affect annual Rh, the response ratio (RR) of
Rh flux to N fertilization decreased firstly during growing season, increased in nongrowing
season and peaked during spring thaw in each year. Nongrowing season Rs and Rh
contributed 5.5–16.4% to their annual fluxes, and were higher in 2012/2013 than other years
due to the extreme snowfall inducing higher soil moisture during spring thaw. The RR of
nongrowing season Rs and Rh decreased in years with extreme snowfall or rainfall compared
to those in normal years. Overall, our results highlight the significant effects of extreme
precipitation on responses of Rs and its components to N fertilization, which should be
incorporated into models to improve the prediction of carbon-climate feedbacks.
Description:
This research was funded by the Chinese Academy of Sciences (XDB15020100) and the
National Natural Science Foundation of China (31561143011).
Description:
2017-12-26
Keywords:
Autotrophic respiration
;
Extreme precipitation
;
Heterotrophic respiration
;
Nitrogen fertilization
;
Nongrowing season
;
Spring thaw
;
Soil respiration
;
Soil waterlogging
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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