关键词: 森林群落, 次生演替, 人类活动干扰, 土壤理化性质

Abstract: With closed static chamber and modified gas chromatograph (HP5890Ⅱ),this paper measured the CO₂ emission from the paddy field of agroforestry ecosystem in hilly area of South China.Gas samples were taken from rice-involved and uninvolved plots simultaneously.In rice-involved plot,the emission was higher at daytime but lower at night,and the diurnal CO₂ emission rate was highly correlated to air temperature,soil surface temperature,and soil temperature at a depth of 5 cm.During rice growth period,the average diurnal CO₂ emission rate was significantly higher in rice－involved than in rice-uninvolved plot.Rice plant played a key role in the CO₂ emission from paddy field.The mean seasonal emission rate of CO₂ in the first and second crop season was 316.29±23.74 and 101.88±16.83 mg·m^-2·h^-1 for rice-involved plot,and 622.40±57.67 and 79.41±19.51mg·m^-2·h^-1 for rice-uninvolved plot,respectively.

Key words: Forest community, Secondary succession, Anthropocentric disturbance, Soil property