The objective of this study was to analyze the effects of climate change and doubled atmospheric CO2 concentrations, as well as the combined effects of climate change and doubling atmospheric CO2 concentrations on soil organic carbon (SOC) in the alpine steppe of the northern Tibetan Plateau using the CENTURY model. The results indicate that SOC loss in climate change scenarios varied from 49.77– 52.36% in the top 20 cm. The simulation results obtained for a P1T0 scenario (increased precipitation and unchanged temperature), P0T1 scenario (unchanged precipitation and increased temperature), and P1T1 scenario (increased precipitation and increased temperature) were similar. The alpine steppe in the P1T1 scenarios lost the greatest amount of SOC (844.40 g C m-2, representing the least amount of SOC) by the end of the simulation. The simulation for P0T1 scenarios resulted in a 49.77% loss of SOC. However, SOC increased 12.87% under the CO2 doubling scenario, compared with the unchanged CO2 scenario. CO2 enhancement effects on SOC were greater than the climate change effects on SOC alone. The simulation of combined climate change and doubling atmospheric CO2 led to a decrease in SOC. This result indicated a decrease of 52.39% in SOC for the P1T1 + 2 × CO2 scenario, 49.81% for the P0T1 + 2 × CO2 scenario, and 52.30% for the P1T0 + 2 × CO2 scenario over the next 50 years. Therefore, SOC content in the alpine steppe will change because of changes in precipitation, temperature and atmospheric CO2 concentrations.
LI Xiaojia, ZHANG Xianzhou, ZHANG Yangjian
. Modeling the Effects of Climate Change and Elevated CO2 on Soil Organic Carbon in an Alpine Steppe[J]. Journal of Resources and Ecology, 2011
, 2(2)
: 168
-174
.
DOI: 10.3969/j.issn.1674-764x.2011.02.010
Alm J, L Schulman, J Walden, H nen Nyk, P Martikainen, et al. 1999. Carbon balance of a boreal bog during a year with an exceptionally dry summer. Ecology, 80 (1), 161-174.
Cao M and F Woodward. 1998. Dynamic responses of terrestrial ecosystem carbon cycling to global climate change. Nature, 393 (1), 249-252.
Gifford R. 1994. The global carbon cycle: a viewpoint on the missing sink. Australian Journal of Plant Physiology ,21 (1), 1-15.
Gilmanov T G, W J Parton and D S Ojima. 1997. Testing the ‘CENTURY’ ecosystem level model on data sets from eight grassland sites in the former USSR representing a wide climatic/soil gradient. Ecological Modelling, 96:191-210.
Houghton J, Ding Y, D Griggs, M Noguer, P Van der Linden, et al. 2001. IPCC, 2001: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, 9.
Houghton R and G Woodwell. 1989. Global climatic change. Scientific American, 260 (4), 36-44.
Luo T, Li W and Zhu H. 2002. Estimated biomass and productivity of natural vegetation on the Tibetan Plateau. Ecological Applications, 12 (4), 980-997.
Meersmans J, F De Ridder, F Canters, S De Baets and M Van Molle. 2008. A multiple regression approach to assess the spatial distribution of Soil Organic Carbon (SOC) at the regional scale (Flanders, Belgium). Geoderma, 143 (1-2), 1-13.
Ni J, 2001. Carbon storage in terrestrial ecosystems of China: estimates at different spatial resolutions and their responses to climate change. Climatic Change, 49 (3), 339-358.
Oechel W, S Hastings, G Vourlitis, M Jenkins, G Riechers, et al. 1993. Recent change of Arctic tundra ecosystems from a net carbon dioxide sink to a source. Nature, 361, 520-523.
Ojima D, W Parton, D Schimel, J Scurlock and T Kittel. 1993. Modeling the effects of climatic and CO2 changes on grassland storage of soil C. Water, Air, & Soil Pollution, 70 (1), 643-657.
Owensby C E, P I Coyne, J M Ham, L M Auen and A K Knapp. 1993. Biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated CO2. Ecological Applications, 3 (4), 644-653.
Parton W, J Scurlock, D Ojima, D Schimel and D Hall. 1995. Impact of climate change on grassland production and soil carbon worldwide. Global Change Biology, 1 (1) , 13-22.
Parton W J, B McKeown, V Kirchner and D S Ojima. 1992. CENTURY Users Manual. Ed. C S University. NREL Publication, Fort Collins, Colorado, USA.
Parton W J, D S Ojima, C V Cole and D S Schimel. 1994. Environmental change in grassland: assessment using models. Climate Change, 28, 111-141.
Parton W J, D S Schimel, C V Cole and D S Ojima. 1987. Analysis of factors controlling soil organic matter levels in Great Plains grasslands. Soil Science Society of America Journal, 51 (5), 1173-1179.
Regional planning office of Naqu, Soil species in Naqa region of Tibet, 1991.
Riedo M, D Gyalistras and J Fuhrer. 2000. Net primary production and carbon stocks in differently managed grasslands: simulation of site-specific sensitivity to an increase in atmospheric CO2 and to climate change. Ecological Modelling, 134 (2-3), 207-227.
Riedo M, D Gyalistras, A Grub, M Rosset and J Fuhrer. 1997. Modelling grassland responses to climate change and elevated CO2. Acta Ecologica, 18 (3), 305-311.
Schimel D, B Braswell, E Holland, R McKeown, D Ojima, et al. 1994.
Climatic, edaphic, and biotic controls over storage and turnover of carbon in soils. Global Biogeochemical Cycles, 8 (3), 279-293.
Schlesinger W H. 1990. Evidence from chronosequence studies for a low carbon-storage potential of soils. Nature, 348 (6298), 232-234.
Thornley J H M and M G R Cannell. 1997. Temperate Grassland Responses to Climate Change: an Analysis using the Hurley Pasture Model. Annals of Botany, 80 (2), 205-221.
Xiao X M, Wang Y F and Chen Z Z. 1996. Dynamics of primary productivity and soil organic matter of typical steppe in the Xilin river basin of Inner Mongolia and their response to climate change. Acta Botanica Sinica 38 (1), 45-52. (in Chinese)
Yang Y, Fang J, Tang Y, Ji C, Zheng C, et al. 2008. Storage, patterns and controls of soil organic carbon in the Tibetan grasslands. Global Change Biology, 14 (7), 1592-1599.
Zhang Y, Tang Y, Jiang J and Yang Y. 2007. Characterizing the dynamics of soil organic carbon in grasslands on the Qinghai-Tibetan Plateau. Science in China Series D: Earth Sciences, 50 (1), 113-120.
Xie X L, Sun B, Zhou H Z, Li Z P and Li A B. 1994. Organic carbon density and storage in soils of China and spatial analysis. Acta Pedologica Sinica, 41 (1), 35-43. (in Chinese)
