陆地生态系统碳水循环的相互作用及其模拟

Interactions between terrestrial ecosystem water and carbon cycles and their simulation methods:A review

回顾了近年来陆地生态系统碳循环与水循环相互作用及模拟方面的进展,指出了今后该领域研究的重点和发展方向。陆地生态系统碳水循环是两个相互耦合的生态学过程,二者及其相互作用均受气候、大气成分和人类活动的影响,并对气候系统具有强烈的反馈作用,因而成为当前全球变化研究的热点。近年来,国内外开展了大量观测和模拟研究,分析了碳循环和水循环在不同时空尺度上的相互作用及其对环境因子和土地利用/覆被变化的响应,发现土壤水分条件对陆地生态系统碳循环的主要分量(光合和呼吸)均具有显著作用,但作用的强度在不同的生态系统存在差异。精确模拟土壤水分动态及其对碳循环的影响是陆地生态系统碳收支估算的基础,碳循环和水循环的耦合模拟是生态和水文模型发展的方向。目前,大部分模型在模拟土壤水分动态时,未考虑地形对土壤水分水平移动的影响,土壤水分对土壤异养呼吸影响的模拟也多采用经验性模型,制约了碳收支模拟的精度,需要加以解决。

This paper reviewed the researches on the interactions between water and carbon cycles in terrestrial ecosystems, and the algorithms developed to simulate these cycles and their interactions. Future research efforts to be taken were also suggested. Carbon and water cycles are the coupled ecological processes in terrestrial ecosystems. They themselves and their interactions are affected by climate, atmospheric composition, and human activities, and impose significant feedbacks on climate system, being the research focuses in global change study. Many observational and modeling studies have been conducted to study the interactions of the two cycles at various spatial and temporal scales as well as their responses to the changes in environmental factors and land cover. Soil water markedly affects the main components of the carbon cycle （ photosynthesis and respiration）, but the affecting strength varies with the types of ecosystems. To accurately simulate soil water dynamics and its roles in the carbon cycle is the basis of reliable simulation of terrestrial carbon budget. Efforts should be taken to implement coupled modeling of carbon and water cycles in ecological and hydrological models. Most of current models ignore the effects of topography on the horizontal redistribution of soil water, and utilize empirical methods to simulate the effects of soil water on heterotrophic respiration, which limit the reliability of carbon budget estimation and needs to be resolved.