论文部分内容阅读
二氧化碳(CO2)、甲烷(CH4)、氧化亚氮(N2O)被认为是最重要的温室气体,在气候变化中扮演着重要角色,实地测定稻田生态系统CO2通量是农业源温室气体监测与控制技术研究的基本内容。采用涡度相关法对江汉平原稻田生态系统进行了通量观测,并对水稻不同生长阶段冠层CO2通量、潜热、显热通量变化特征及其影响因素进行了分析。结果表明:水稻各生育期冠层CO2、潜热、显热通量日变化均表现出明显的单峰特征,但幅度不同,这与太阳总辐射的日变化及下垫面作物叶面积指数大小关系密切。稻田系统作物呼吸与土壤呼吸排放CO2,排放通量一方面与温度的变化有关,另一方面也受灌溉、作物生长状况的影响;稻田光合作用吸收同化大气CO2,吸收通量与作物群体叶面积指数大小、光合有效辐射强度有关。不同生长期冠层CO2通量与温度因子(气温、5cm土层温度)、光辐射强度因子(时光合有效辐射曝辐量)的相关性均达到极显著水平(P<0.01),其中,分蘖-灌浆乳熟期CO2净通量对时光合有效辐射曝辐量响应的灵敏度较大,可以通过直角双曲线模型来拟合评估CO2净通量。
Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are considered to be the most important greenhouse gases and play an important role in climate change. On-the-spot measurement of CO2 fluxes in paddy field ecosystems is an agricultural source of greenhouse gas monitoring and control The basic content of technical research. The eddy covariance method was used to observe the flux of paddy field ecosystem in Jianghan Plain and the change characteristics of canopy CO2 flux, latent heat and sensible heat flux in different growth stages of rice and its influencing factors were analyzed. The results showed that the diurnal variations of CO2, latent heat and sensible heat flux in canopy all showed obvious unimodal characteristics, but with different amplitudes, which was related to the diurnal variation of total solar radiation and the leaf area index close. Rice crop system respiration and soil respiration emissions of CO2, the emission flux on the one hand with the temperature changes on the other hand, also affected by irrigation, crop growth conditions; paddy field photosynthesis absorption and assimilation of atmospheric CO2, flux and leaf area of crop groups Index size, photosynthetically active radiation intensity. The correlation between canopy CO2 flux and temperature (temperature, 5cm soil temperature) and light radiation intensity (time-lapse effective radiation exposure) reached the significant level at different growth stages (P <0.01) - CO2 fluxes during milky-milky grouting are sensitive to the response of the photosynthetically active radiation exposure, and the net flux of CO2 can be fitted and evaluated by a rectangular hyperbola model.