The eddy covariance system can monitor the fluctuations of 3-D wind components, sonic temperature, water vapor and CO2 concentrations.
Raw data were collected at a frequency of 10 Hz and half-hour flux data were recorded by a datalogger (Model CR5000, Campbell Scientific Inc.,USA). Meteorological variables, such as air temperature, air humidity,solar radiation, net radiation, photosynthetically active radiation (PAR) and precipitation, were measured at the same time.
Inaddition, soil temperature at five depths (0, 5, 10, 15 and 20 cm),soil moisture at the 20-cm depth and soil heat flux were monitored.