The greenhouse effect exacerbated by the increase of carbon-containing gases is the important cause of the climate change.On-line CO_2 concentration monitoring of terrestrial ecosystem and CO2 flux analyzing are crucial for knowing regional climate and improving environment.The open-path CO_2 monitoring system based on tunable diode laser absorption spectroscopy technology was designed and used for CO_2 concentration fn-situ detection in wheat field at State Experimental Station of Agro-Ecosystem in Fengqiu...