Sensitivity of Temperate Desert Steppe Carbon Exchange to Seasonal Droughts and Precipitation Variations in Inner Mongolia, China

Yang, Fulin; Zhou, Guangsheng
February 2013
PLoS ONE;Feb2013, Vol. 8 Issue 2, p1
Academic Journal
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 CO2 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 CO2 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 (NEEsat) and the temperature sensitivity coefficient of ecosystem respiration (Reco) exhibited significant variations. The values of NEEsat were −2.6, −2.9, and −1.4 µmol CO2 m−2 s−1 in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP) and Reco, and the drought sensitivity of GPP was greater than that of Reco. 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.


Related Articles

  • Effects of Elevated CO2 and Nitrogen Deposition on Ecosystem Carbon Fluxes on the Sanjiang Plain Wetland in Northeast China. Wang, Jianbo; Zhu, Tingcheng; Ni, Hongwei; Zhong, Haixiu; Fu, Xiaoling; Wang, Jifeng // PLoS ONE;Jun2013, Vol. 8 Issue 6, p1 

    Background: Increasing atmospheric CO2 and nitrogen (N) deposition across the globe may affect ecosystem CO2 exchanges and ecosystem carbon cycles. Additionally, it remains unknown how increased N deposition and N addition will alter the effects of elevated CO2 on wetland ecosystem carbon...

  • Regional Contingencies in the Relationship between Aboveground Biomass and Litter in the World’s Grasslands. O’Halloran, Lydia R.; Borer, Elizabeth T.; Seabloom, Eric W.; MacDougall, Andrew S.; Cleland, Elsa E.; McCulley, Rebecca L.; Hobbie, Sarah; Harpole, W. Stan; DeCrappeo, Nicole M.; Chu, Chengjin; Bakker, Jonathan D.; Davies, Kendi F.; Du, Guozhen; Firn, Jennifer; Hagenah, Nicole; Hofmockel, Kirsten S.; Knops, Johannes M. H.; Li, Wei; Melbourne, Brett A.; Morgan, John W. // PLoS ONE;Feb2013, Vol. 8 Issue 2, p1 

    Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically...

  • Organic Carbon Storage in Four Ecosystem Types in the Karst Region of Southwestern China. Liu, Yuguo; Liu, Changcheng; Wang, Shijie; Guo, Ke; Yang, Jun; Zhang, Xinshi; Li, Guoqing // PLoS ONE;Feb2013, Vol. 8 Issue 2, p1 

    Karst ecosystems are important landscape types that cover about 12% of the world's land area. The role of karst ecosystems in the global carbon cycle remains unclear, due to the lack of an appropriate method for determining the thickness of the solum, a representative sampling of the soil and...

  • Flow regime alteration effects on the organic C dynamics in semiarid stream ecosystems. Acu�a, V. // Hydrobiologia;Dec2010, Vol. 657 Issue 1, p233 

    There is evidence of an ongoing alteration of the flow regime owing to climate change forcing, which has resulted in substantial increases in the frequency and magnitude of extreme events such as floods and droughts. Such changes in the flow regime may have major implications in freshwater...

  • Hysteresis response of daytime net ecosystem CO2 exchange during a drought. Pingintha, N.; Leclerc, M. Y.; Beasley Jr., J. P.; Zhang, G.; Senthong, C.; Rowland, D. // Biogeosciences Discussions;2009, Vol. 6 Issue 6, p10707 

    Continuous measurements of net ecosystem CO2 exchange (NEE) using the eddycovariance method were made over an agricultural ecosystem in the southeastern US. During optimum environmental conditions, photosynthetically active radiation (PAR) was the primary climatic factor controlling daytime NEE,...

  • Scaling metabolism from organisms to ecosystems. Enquist, Brian J.; Economo, Evan P.; Huxman, Travis E.; Allen, Andrew P.; Ignace, Danielle D.; Gillooly, James F. // Nature;6/5/2003, Vol. 423 Issue 6940, p639 

    Understanding energy and material fluxes through ecosystems is central to many questions in global change biology and ecology[SUP1-11]. Ecosystem respiration is a critical component of the carbon cycle[SUP1,5-7] and might be important in regulating biosphere response to global climate...

  • Annual fluxes of carbon from deforestation and regrowth in the Brazilian Amazon. Houghton, R.A.; Skole, D.L. // Nature;1/20/2000, Vol. 403 Issue 6767, p301 

    Investigates the contribution of deforestation and agricultural land abandonment in the Brazilian Amazon in the annual flux of carbon in the region. Offsetting of carbon sinks calculated for natural ecosystems in the region by land use change and fire as source of carbon; Interannual...

  • High-resolution organic carbon isotope record across the Cretaceous—Tertiary boundary in south-central Alberta: implications for the post-impact recovery rate of terrestrial ecosystems and use of δ13C as a boundary marker. Therrien, François; Eberth, David A.; Braman, Dennis R.; Zelenitsky, Darla K. // Canadian Journal of Earth Sciences;Apr2007, Vol. 44 Issue 4, p529 

    A high-resolution study identified a δ13C excursion of –1.8‰ to –2.3‰ in terrestrial organic matter across the Cretaceous–Tertiary (K–T) boundary at two localities in the Scollard Formation of south-central Alberta, one of the northernmost occurrences of...

  • Seasonality of foliar respiration in two dominant plant species from the Arctic tundra: response to long-term warming and short-term temperature variability. Heskel, Mary A.; Bitterman, Danielle; Atkin, Owen K.; Turnbull, Matthew H.; Griffin, Kevin L. // Functional Plant Biology;2014, Vol. 41 Issue 3, p287 

    Direct measurements of foliar carbon exchange through the growing season in Arctic species are limited, despite the need for accurate estimates of photosynthesis and respiration to characterise carbon cycling in the tundra. We examined seasonal variation in foliar photosynthesis and respiration...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics