Study On Soil Respiration Measurement Method Based On Conservation Of Species Mass

Soil respiration monitoring is an important part of global carbon cycle and climate change research,and it has great significance for global carbon balance research.Among them,the chamber monitoring method is the most widely used,but long-term monitoring can lead to underestimation of soil respiration.In response to this problem,the research team independently developed a set of open soil respiration monitors,which can obtain soil respiration values,but the accuracy of its internal sensor placement and soil respiration measurement models needs to be improved.In this paper,the optimal placement of sensors in the chamber was firstly studied by Bayesian theory.Then,through the theory of species massconservation and the characteristics of open chamber,a soil respiration measurement model with species mass-conservation was proposed,and its long-term monitoring accuracy was compared with the three internationally used monitoring methods.In addition,a multi-measurement point morning,midnight and evening experiment was carried out to analyze its reliability.The main research conclusions are as follows:(1)Experiment shows that the optimal placement of the sensors of the open soil respiration monitor is between 0.028 m and 0.268 m in height.At the same time,the experimental correlation analysis shows that the optimal point placement algorithm is reasonable and effective.(2)The average value of the data measured by the open soil respiration monitor after the data noise reduction preprocessing is close to the original data,and the data mean square deviation and relative deviation after the data noise reduction preprocessing are all smaller than the original data,indicating the data denoising preprocessing method has good validity,reliability and stability.(3)Experiment shows that the soil respiration measurement method with species massconservation has certain advantages in long-term monitoring.At the same time,comparison experiment between this method and three general soil respiration measurement methods shows that the soil respiration measurement method with species mass-conservation has good accuracy and stability.In addition,the multi-measurement point morning,midnight and evening experiment shows that the soil respiration measurement method with species mass-conservation has good reliability and rationality.This research aims to improve the reliability and accuracy of soil respiration monitoring,provide more reliable basic data for the study of global climate change and carbon cycle,and provide important data support for carbon neutrality and carbon trading.It has important theoretical significance and application value.