Analysis of carbon sink efficiency of trees based on gas photoacoustic spectroscopy detection

Carbon sinks are natural or man-made systems that absorb and store carbon dioxide (CO₂) or other greenhouse gases, thereby helping to reduce greenhouse gas concentrations in the atmosphere, and they play an irreplaceable role in the restoration of the ecological environment. Among the current methods for analyzing the carbon sink efficiency of trees, the accuracy and reliability of remote sensing technology are not high. The carbon isotope method cannot guarantee real-time performance, which also greatly affects the development of the carbon trading industry. A gas absorption to laser pulses can excite an acoustic waves, and the gas content can be measured by detecting the size of the wave, which is called photoacoustic(PA) detection technology. In this work, several trees were used as the research object, and an all-optical multi-component PA spectrometer was used to detect the concentration of feature gases in the air nearby the trees. The volume content of C₂H₂, CO₂ and CH₄ respectively is detected out, and the volume content of the three gases varies with the trees. Based on the idea of carbon source and generalized carbon source, the three gases can be used to estimate trees’ capacity for sinking carbon sources or mediating ability to carbon source emissions.