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Biogeosciences Discuss., 9, 4025-4066, 2012
www.biogeosciences-discuss.net/9/4025/2012/ doi:10.5194/bgd-9-4025-2012 © Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. |
The carbon budget of terrestrial ecosystems in East Asia over the last two decades
1College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
2Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China
3Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
4Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
5Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
6Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UVSQ, 91191 Gif sur Yvette, France
7Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6290, USA
8Climate Physics Laboratory, School of Earth and Environmental Sciences, Seoul National University, Seoul 151-742, Korea
9Xinjiang institute of ecology and geography, Chinese Academy of Sciences, Urumqi 830011, China
10River Basin Research Center, Gifu University, Gifu 501-1193, Japan
11Laboratory for Ecological Forecasting and Global Change, College of Forestry, Northwest A & F University, Yangling, Shaanxi 712100, China
12ECCOREV FR 3098, CNRS/Aix-Marseille Université, BP 80, 13545 Aix-en-Provence Cedex 4, France
13School of Geography, University of Exeter, Exeter EX4 4QF, UK
14Ecosystem Dynamics and Global Ecology Laboratory, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA
15Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20740, USA
16Department of Horticulture, Cornell University, Ithaca, NY 14853, USA
Abstract. This REgional Carbon Cycle Assessment and Processes regional study provides a synthesis of the carbon balance of terrestrial ecosystems in East Asia, a region comprised of China, Japan, North- and South-Korea, and Mongolia. We estimate the current terrestrial carbon balance of East Asia and its driving mechanisms during 1990–2009 using three different approaches: inventories combined with satellite greenness measurements, terrestrial ecosystem carbon cycle models and atmospheric inversion models. The magnitudes of East Asia's natural carbon sink from these three approaches are comparable: −0.264 ± 0.033 Pg C yr−1 from inventory-remote sensing model-data fusion approach, −0.393 ± 0.141 Pg C yr−1 (not considering biofuel emissions) or −0.204 ± 0.141 Pg C yr−1 (considering biofuel emissions) for carbon cycle models, and −0.270 ± 0.507 Pg C yr−1 for atmospheric inverse models. The ensemble of ecosystem modeling based analyses further suggests that at the regional scale, climate change and rising atmospheric CO2 together resulted in a carbon sink of −0.289 ± 0.135 Pg C yr−1, while land use change and nitrogen deposition had a contribution of −0.013 ± 0.029 Pg C yr−1 and −0.107 ± 0.025 Pg C yr−1, respectively. Although the magnitude of climate change effects on the carbon balance varies among different models, all models agree that in response to climate change alone, southern China experienced an increase in carbon storage from 1990 to 2009, while northern East Asia including Mongolia and north China showed a decrease in carbon storage. Overall, our results suggest that about 13–26% of East Asia's CO2 emissions from fossil fuel burning have been offset by carbon accumulation in its terrestrial ecosystems over the period from 1990 to 2009. The underlying mechanisms of carbon sink over East Asia still remain largely uncertain, given the diversity and intensity of land management processes, and the regional conjunction of many drivers such as nutrient deposition, climate, atmospheric pollution and CO2 changes, which cannot be considered as independent for their effects on carbon storage.
Citation: Piao, S., Ito, A., Li, S., Huang, Y., Ciais, P., Wang, X., Peng, S., Andres, R. J., Fang, J., Jeong, S., Mao, J., Mohammat, A., Muraoka, H., Nan, H., Peng, C., Peylin, P., Shi, X., Sitch, S., Tao, S., Tian, H., Xu, M., Yu, G., Zeng, N., and Zhu, B.: The carbon budget of terrestrial ecosystems in East Asia over the last two decades, Biogeosciences Discuss., 9, 4025-4066, doi:10.5194/bgd-9-4025-2012, 2012.