Seasonal variation of carbon exchange of typical forest ecosystems along the eastern forest transect in China |
| |
| Authors: | Zhang Leiming Yu Guirui Sun Xiaomin Wen Xuefa Ren Chuanyou Song Xia Liu Yunfen Guan Dexin Yan Junhua Zhang Yiping |
| |
| Institution: | 1.Synthesis Center of Chinese Ecosystem Research Network (CERN), Institute of Geographic Sciences and Natural Re-sources Research,Chinese Academy of Sciences,Beijing,China;2.Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang,China;3.South China Institute of Botany,Chinese Academy of Sciences,Guangzhou,China;4.Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Kunming,China;5.Graduate University of Chinese Academy of Sciences,Beijing,China |
| |
| Abstract: | The long-term and continuous carbon fluxes of Changbaishan temperate mixed forest (CBS), Qianyanzhou subtropical evergreen coniferous forest (QYZ), Dinghushan subtropical evergreen mixed forest (DHS) and Xishuangbana tropical rainforest (XSBN) have been measured with eddy covariance techniques. In 2003, different responses of carbon exchange to the environment appeared across the four ecosystems. At CBS, the carbon exchange was mainly determined by radiation and temperature. 0°C and 10°C were two important temperature thresholds; the former determined the length of the growing season and the latter affected the magnitude of carbon exchange. The maximum net ecosystem exchange (N EE) of CBS occurred in early summer because maximum ecosystem photosynthesis (G PP) occurred earlier than maximum ecosystem respiration (R e). During summer, QYZ experienced severe drought and N EE decreased significantly mainly as a result of the depression of G PP. At DHS and XSBN, N EE was higher in the drought season than the wet season, especially the conversion between carbon sink and source occurring during the transition season at XSBN. During the wet season, increased fog and humid weather resulted from the plentiful rainfall, the ecosystem G PP was dispressed. The Q 10 and annual respiration of XSBN were the highest among the four ecosystems, while the average daily respiration of CBS during the growing season was the highest. Annual N EE of CBS, QYZ, DHS and XSBN were 181.5, 360.9, 536.2 and ?320.0 g·C·m?2·a?1, respectively. From CBS to DHS, the temperature and precipitation increased with the decrease in latitude. The ratio of N EE/R e increased with latitude, while R e/G PP, ecosystem light use efficiency (L UE), precipitation use efficiency and average daily G PP decreased gradually. However, XSBN usually escaped such latitude trend probably because of the influence of the south-west monsoon climate which does not affect the other ecosystems. Long-term measurement and more research were necessary to understand the adaptation of forest ecosystems to climate change and to evaluate the ecosystem carbon balance due to the complexity of structure and function of forest ecosystems. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
