森林碳计量方法研究进展

森林是陆地生态系统的主体,不仅是巨大的碳库而且对减缓气候变暖具有积极作用。科学有效的森林碳计量方法,有助于加深对全球碳循环过程的理解。然而,由于森林生态系统结构复杂,对森林碳计量的估算结果普遍存在精度低、不确定性高的问题。近年来,国内外发展了大量对森林碳计量进行估算的方法,主要有基于样地清查的森林植被和土壤碳估算、基于生长收获的经验模型估算、基于定量遥感雷达观测的遥感估测、基于多尺度森林生态系统网络的通量观测和陆地生态系统过程模型模拟等方法。在实际的森林碳计量中,根据不同的森林类型特征和数据获取情况,往往采取不同的碳计量方法,甚至不止一种。以生态过程模型模拟、遥感反演和数据同化技术为主要手段,基于碳通量观测数据、控制实验数据和遥感影像数据,发展多学科、多过程、多尺度的综合联网观测,充分认识森林碳循环过程中碳源/汇的时空分布特征,开展区域、洲际乃至全球尺度碳循环及其对全球变化和人类活动响应的系统性、集成性研究,以便建立高效、可靠的碳计量体系是未来林业碳计量的发展趋势。随着世界各国温室气体排放清单的编制,中国迫切需要科学的方法体系计量森林碳源/汇,提升我国在生态环境问题上的国际发言权和主导权,同时对我国森林可持续经营、生态环境保护以及美丽中国建设提供建议与支持。分析了各类森林碳计量方法的主要特征、优缺点,同时探讨了目前的森林碳计量方法存在的问题和未来的发展趋势,为不同时空尺度下森林碳计量提供参考。

An overview of forest carbon measurement methods

Forests are the main body of terrestrial ecosystems; they are not only huge carbon stocks, but also have a positive effect on mitigating climate warming. Effective scientific forest carbon inventory measurement methods help to elucidate the global carbon cycle. Generally, however, due to the complex structure of forest ecosystems, the estimation of forest carbon measurements has had problems of low accuracy and high uncertainty. In recent years, a large number of methods for estimating forest carbon have been developed domestically and overseas. These methods mainly include forest vegetation and soil carbon estimation methods based on the inventory of sample plots, growth harvesting-based empirical model estimation and remote sensing estimation based on quantitative remote sensing and radar observations data, flux observations based on multi-scale forest ecosystem networks, and numerical simulation based on terrestrial ecosystem process models. In actual forest carbon measurement, different (or even multiple) carbon measurement methods are often used depending on the characteristics of different forest types and data acquisition. From the main methods of ecological process model simulation, remote sensing inversion, and data assimilation techniques, and based on multi-source data from carbon flux observation, a control experiment and remote sensing, multi-disciplinary, multi-process, and multi-scale integrated network observations have been developed to fully understand the spatial and temporal distribution characteristics of carbon sources and sinks in the cycle process. Systematic and integrated studies on carbon cycles have been carried out at regional, continental, and global scales, and their response to global changes and human activities, in order to establish an efficient and reliable carbon measurement system. These research aspects will be the development trend of forestry carbon measurements in the future. With the preparation of greenhouse gas emission inventories in various countries, China urgently needs a scientific method system to measure forest carbon sources and sinks in order to increase their international voice and dominance in ecological and environmental issues, and provide suggestions and support for sustainable forest management and ecological and environmental protection. This paper analyzes the main characteristics, advantages, and disadvantages of various forest carbon measurement methods, and discusses existing problems and the future development trend in forest carbon measurement methods, providing reference for forest carbon measurements under different spatial and temporal scales.