箱式通量观测技术和方法的理论假设及其应用进展

碳(CO₂、CH₄)、氮(N₂O)和水汽(H₂O)等温室气体的交换通量是生态系统物质循环的核心, 是地圈-生物圈-大气圈相互作用的纽带。稳定同位素光谱和质谱技术和方法的进步使碳稳定同位素比值(δ ¹³C)和氧稳定同位素比值(δ ¹⁸O)(CO₂)、δ ¹³C (CH₄)、氮稳定同位素比值(δ ¹⁵N)和δ ¹⁸O (N₂O)、氢稳定同位素比值(δD)和δ ¹⁸O (H₂O)的观测成为可能, 与箱式通量观测技术和方法结合可以实现土壤、植物乃至生态系统尺度温室气体及其同位素通量观测研究。该综述以CO₂及其δ ¹³C通量的箱式观测技术和方法为例, 概述了箱式通量观测系统的基本原理及分类, 阐述了系统设计的理论要求和假设, 综述了从野外到室内土壤、植物叶-茎-根以及生态系统尺度箱式通量观测研究的应用进展及问题, 展望了气体分析精度和准确度、观测数据精度和准确度以及观测数据的代表性评价在箱式通量观测研究中的重要性。

Theory,hypothesis and application advance in chamber-based technology and methods for flux measurement

The exchange flux of greenhouse gases, such as carbon (CO₂, CH₄), nitrogen (N₂O) and water vapour (H₂O), is the core of material cycle in the ecosystem and the bond of interaction among geosphere, biosphere and atmosphere. The development of stable isotope infrared spectroscopy and mass spectrometry technology and methods makes it possible to measure carbon stable isotopic composition (δ ¹³C) and oxygen stable isotopic composition (δ ¹⁸O)(CO₂), δ ¹³C (CH₄), nitrogen stable isotope composition (δ ¹⁵N) and δ ¹⁸O (N₂O), hydrogen stable isotopic composition (δD) and δ ¹⁸O (H₂O), which realizes the observation of greenhouse gas and its isotope flux at the soil, plant and ecosystem scales in combined with chamber-based technology and methods for flux measurement. Taking the chamber-based technology and methods for CO₂ and its δ ¹³C flux measurement as an example, this review which summarizes the basic principle and classification of the flux measurement system, expounds the theory requirements and assumptions of system design, summarizes the application advance and problems of chamber-based technology and methods for flux measurement in soil, plants (leaf, stem, and root) and ecosystem scales from the field to indoor, and prospects the importance of precision and accuracy of gas analysis and measurement data and the representativeness of measurement data in chamber-based flux measurement.