Responses of Soil CO2 Efflux to Precipitation Pulses in Two Subtropical Forests in Southern China |
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出 版 社：Environmental Management |
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发表时间：2011 |
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台 站：鼎湖山森林生态系统定位研究站 |
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作 者：Qi Deng,Guoyi Zhou,Shizhong Liu,Guowei Chu,Deqiang Zhang
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点 击 率：13489 |
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关 键 字：Climate change,Soil CO2 efflux,Subtropical forest,Precipitation pulse |
| 摘 要：This study was designed to examine the responses of soil CO2 efflux to precipitation pulses of varying intensities using precipitation simulations in two subtropical forests [i.e., mixed and broadleaf forests (MF and BF)] in southern China. The artificial precipitation
event was achieved by spraying a known amount of water evenly in a plot (50 9 50 cm2) over a 30 min period, with intensities ranging from 10, 20, 50 and 100 mm within the 30min. The various intensities were simulated in both dry season (in December 2007) and wet (in May 2008) season. We characterized the dynamic patterns of soil CO2 efflux rate and environmental factors over the 5 h experimental
period. Results showed that both soil moisture and soil CO2 efflux rate increased to peak values for most of the simulated precipitation treatments, and gradually returned to the pre-irrigation levels after irrigation in two forests. The maximum peak of soil CO2 efflux rate occurred at the 10mm precipitation event in the dry season in BF and was about 3.5 times that of the pre-irrigation value. The change in cumulative soil CO2 efflux following precipitation pulses ranged from -0.68 to 1.72gCO2 m-2 over 5h compared to the pre-irrigation levels and was generally larger in the dry season than in the wet season. The positive responses of soil CO2 efflux to precipitation pulses declined with the increases in precipitation intensity, and surprisingly turned to negative when precipitation intensity reached 50 and 100mm in the wet season. These findings indicated that soil CO2 efflux could be changed via pulselike fluxes in subtropical forests in southern China as fewer
but extreme precipitation events occur in the future. |
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 邓琦，周国逸-2011-Environmental Management-Responses of Soil CO2 Efflux to Precipitation Pulses in Two Subtropical Forests in Southern China.PDF |
