Knowledge Management System of Northwest Institute of Plateau Biology, CAS
| Diurnal, seasonal and annual variation in net ecosystem CO2 exchange of an alpine shrubland on Qinghai-Tibetan plateau | |
| Zhao, Liang; Li, Yingnian; Xu, Shixiao; Zhou, Huakun; Gu, Song; Yu, Guirui; Zhao, Xinquan | |
| 2006-10-01 | |
| 发表期刊 | GLOBAL CHANGE BIOLOGY
 |
| 卷号 | 12期号:10页码:1940-1953 |
| 文章类型 | Article |
| 摘要 | Thus far, grassland ecosystem research has mainly been focused on low-lying grassland areas, whereas research on high-altitude grassland areas, especially on the carbon budget of remote areas like the Qinghai-Tibetan plateau is insufficient. To address this issue, flux of CO2 were measured over an alpine shrubland ecosystem (37 degrees 36'N, 101 degrees 18'E; 325 above sea level [a. s. l.]) on the Qinghai-Tibetan Plateau, China, for 2 years (2003 and 2004) with the eddy covariance method. The vegetation is dominated by formation Potentilla fruticosa L. The soil is Mol-Cryic Cambisols. To interpret the biotic and abiotic factors that modulate CO2 flux over the course of a year we decomposed net ecosystem CO2 exchange (NEE) into its constituent components, and ecosystem respiration (R-eco). Results showed that seasonal trends of annual total biomass and NEE followed closely the change in leaf area index. Integrated NEE were -58.5 and -75.5 g C m(-2), respectively, for the 2003 and 2004 years. Carbon uptake was mainly attributed from June, July, August, and September of the growing season. In July, NEE reached seasonal peaks of similar magnitude (4-5 g C m(-2) day(-1)) each of the 2 years. Also, the integrated night-time NEE reached comparable peak values (1.5-2 g C m(-2) day(-1)) in the 2 years of study. Despite the large difference in time between carbon uptake and release (carbon uptake time < release time), the alpine shrubland was carbon sink. This is probably because the ecosystem respiration at our site was confined significantly by low temperature and small biomass and large day/night temperature difference and usually soil moisture was not limiting factor for carbon uptake. In general, R-eco was an exponential function of soil temperature, but with season-dependent values of Q(10). The temperature-dependent respiration model failed immediately after rain events, when large pulses of R-eco were observed. Thus, for this alpine shrubland in Qinghai-Tibetan plateau, the timing of rain events had more impact than the total amount of precipitation on ecosystem R-eco and NEE.; Thus far, grassland ecosystem research has mainly been focused on low-lying grassland areas, whereas research on high-altitude grassland areas, especially on the carbon budget of remote areas like the Qinghai-Tibetan plateau is insufficient. To address this issue, flux of CO2 were measured over an alpine shrubland ecosystem (37 degrees 36'N, 101 degrees 18'E; 325 above sea level [a. s. l.]) on the Qinghai-Tibetan Plateau, China, for 2 years (2003 and 2004) with the eddy covariance method. The vegetation is dominated by formation Potentilla fruticosa L. The soil is Mol-Cryic Cambisols. To interpret the biotic and abiotic factors that modulate CO2 flux over the course of a year we decomposed net ecosystem CO2 exchange (NEE) into its constituent components, and ecosystem respiration (R-eco). Results showed that seasonal trends of annual total biomass and NEE followed closely the change in leaf area index. Integrated NEE were -58.5 and -75.5 g C m(-2), respectively, for the 2003 and 2004 years. Carbon uptake was mainly attributed from June, July, August, and September of the growing season. In July, NEE reached seasonal peaks of similar magnitude (4-5 g C m(-2) day(-1)) each of the 2 years. Also, the integrated night-time NEE reached comparable peak values (1.5-2 g C m(-2) day(-1)) in the 2 years of study. Despite the large difference in time between carbon uptake and release (carbon uptake time < release time), the alpine shrubland was carbon sink. This is probably because the ecosystem respiration at our site was confined significantly by low temperature and small biomass and large day/night temperature difference and usually soil moisture was not limiting factor for carbon uptake. In general, R-eco was an exponential function of soil temperature, but with season-dependent values of Q(10). The temperature-dependent respiration model failed immediately after rain events, when large pulses of R-eco were observed. Thus, for this alpine shrubland in Qinghai-Tibetan plateau, the timing of rain events had more impact than the total amount of precipitation on ecosystem R-eco and NEE. |
| 关键词 | Ecosystem Respiration Net Ecosystem Carbon Exchange Precipitation Qinghai-tibetan Plateau Soil Moisture |
| WOS标题词 | Science & Technology ; Life Sciences & Biomedicine |
| 学科领域 | 生物科学 |
| 关键词[WOS] | CARBON-DIOXIDE EXCHANGE ; NATIVE TALLGRASS PRAIRIE ; SOIL RESPIRATION ; WATER-VAPOR ; INTERANNUAL VARIABILITY ; TEMPERATE GRASSLAND ; FOREST ; FLUX ; ENERGY ; MEADOW |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
| WOS类目 | Biodiversity Conservation ; Ecology ; Environmental Sciences |
| WOS记录号 | WOS:000240561000010 |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://210.75.249.4/handle/363003/1317 |
| 专题 | 中国科学院西北高原生物研究所 |
| 作者单位 | 1.Chinese Acad Sci, NW Plateau Inst Biol, Qinghai 810001, Peoples R China 2.Inst Geog Sci & nat Resources Res, Beijing 100101, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhao, Liang,Li, Yingnian,Xu, Shixiao,et al. Diurnal, seasonal and annual variation in net ecosystem CO2 exchange of an alpine shrubland on Qinghai-Tibetan plateau[J]. GLOBAL CHANGE BIOLOGY,2006,12(10):1940-1953. |
| APA | Zhao, Liang.,Li, Yingnian.,Xu, Shixiao.,Zhou, Huakun.,Gu, Song.,...&Zhao, Xinquan.(2006).Diurnal, seasonal and annual variation in net ecosystem CO2 exchange of an alpine shrubland on Qinghai-Tibetan plateau.GLOBAL CHANGE BIOLOGY,12(10),1940-1953. |
| MLA | Zhao, Liang,et al."Diurnal, seasonal and annual variation in net ecosystem CO2 exchange of an alpine shrubland on Qinghai-Tibetan plateau".GLOBAL CHANGE BIOLOGY 12.10(2006):1940-1953. |
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