PMID- 23393576
OWN - NLM
STAT- MEDLINE
DCOM- 20130826
LR  - 20211021
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 8
IP  - 2
DP  - 2013
TI  - Sensitivity of temperate desert steppe carbon exchange to seasonal droughts and 
      precipitation variations in Inner Mongolia, China.
PG  - e55418
LID - 10.1371/journal.pone.0055418 [doi]
LID - e55418
AB  - Arid grassland ecosystems have significant interannual variation in carbon 
      exchange; however, it is unclear how environmental factors influence carbon 
      exchange in different hydrological years. In this study, the eddy covariance 
      technique was used to investigate the seasonal and interannual variability of CO(2) 
      flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. 
      The amounts and times of precipitation varied significantly throughout the study 
      period. The precipitation in 2009 (186.4 mm) was close to the long-term average 
      (183.9+/-47.6 mm), while the precipitation in 2008 (136.3 mm) and 2010 (141.3 mm) 
      was approximately a quarter below the long-term average. The temperate desert 
      steppe showed carbon neutrality for atmospheric CO(2) throughout the study period, 
      with a net ecosystem carbon dioxide exchange (NEE) of -7.2, -22.9, and 26.0 g C 
      m(-)(2) yr(-)(1) in 2008, 2009, and 2010, not significantly different from zero. The 
      ecosystem gained more carbon in 2009 compared to other two relatively dry years, 
      while there was significant difference in carbon uptake between 2008 and 2010, 
      although both years recorded similar annual precipitation. The results suggest 
      that summer precipitation is a key factor determining annual NEE. The apparent 
      quantum yield and saturation value of NEE (NEE(sat)) and the temperature 
      sensitivity coefficient of ecosystem respiration (R(eco)) exhibited significant 
      variations. The values of NEE(sat) were -2.6, -2.9, and -1.4 micromol CO(2) m(-)(2) s(-)(1) in 
      2008, 2009, and 2010, respectively. Drought suppressed both the gross primary 
      production (GPP) and R(eco), and the drought sensitivity of GPP was greater than 
      that of R(eco). The soil water content sensitivity of GPP was high during the dry 
      year of 2008 with limited soil moisture availability. Our results suggest the 
      carbon balance of this temperate desert steppe was not only sensitive to total 
      annual precipitation, but also to its seasonal distribution.
FAU - Yang, Fulin
AU  - Yang F
AD  - Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, 
      Key Open Laboratory of Arid Climatic Change and Disaster Reduction of China 
      Meteorological Administration-CMA, Institute of Arid Meteorology, CMA, Lanzhou, 
      China.
FAU - Zhou, Guangsheng
AU  - Zhou G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130205
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 7440-44-0 (Carbon)
SB  - IM
MH  - Carbon/*analysis
MH  - China
MH  - *Desert Climate
MH  - *Droughts
PMC - PMC3564909
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2013/02/09 06:00
MHDA- 2013/08/27 06:00
PMCR- 2013/02/05
CRDT- 2013/02/09 06:00
PHST- 2012/09/11 00:00 [received]
PHST- 2012/12/22 00:00 [accepted]
PHST- 2013/02/09 06:00 [entrez]
PHST- 2013/02/09 06:00 [pubmed]
PHST- 2013/08/27 06:00 [medline]
PHST- 2013/02/05 00:00 [pmc-release]
AID - PONE-D-12-27749 [pii]
AID - 10.1371/journal.pone.0055418 [doi]
PST - ppublish
SO  - PLoS One. 2013;8(2):e55418. doi: 10.1371/journal.pone.0055418. Epub 2013 Feb 5.