稳定性同位素技术在森林生态系统碳水通量组分区分中的应用

Applications of Stable Isotope Techniques to Determine Components of CO_2 and H_2O Fluxes in Forest Ecosystems

生态系统碳水循环过程中的同位素分馏效应,为区分生态系统净碳交换过程中光合和呼吸通量,蒸散通量中植物蒸腾和土壤蒸发提供了理论依据。本文综述了稳定性同位素技术在这一领域的应用进展。研究结果显示,此方法切实可行,为进一步解释森林生态系统过程提供了广阔的前景。但由于森林生态系统结构复杂,不确定性因素多,国内外研究还处于尝试阶段。该方法在森林生态系统应用中还存在诸如Keeling图技术和涡度相关技术的假设条件难以满足等问题,期待今后在技术和理论上的突破。

Isotopic fractionation during the carbon and water processes of ecosystem provides the chances to partition ecosystem CO2 flux into photosynthesis flux and respiration flux, and partition evapotranspiration flux into soil evaporation flux and plant transpiration flux. In this paper stable isotope techniques applied to forest ecosystems were overviewed. Research results showed that applications of stable isotope techniques to determine components of CO2 and evapotranspiration fluxes in forest ecosystems were possible. But because of the complexity and uncertainty of forest ecosystems, studies in this field were difficult. Many problems were to be solved urgently, for example, the techniques relied on Keeling plot and eddy covariance techniques but their hypothesis were difficult to be match in forest ecosystems, expecting the progresses in techniques and theories.