现代陆生植物碳同位素组成对气候变化的响应研究进展

Research Progress in Responses of Modern Terrestrial Plant Carbon Isotope Composition to Climate Change

植物组织的碳同位素组成(δ13C)能够记录气候变化的信息,因而被作为指示气候环境变化的一个重要代用指标,并广泛应用于全球变化研究。然而,气候环境变化引起的现代植物δ13C及其指示的气候环境意义的不确定性限制了植物δ13C在气候环境变化等领域研究中的应用。在概述植物碳同位素分馏和不同光合型植物碳同位素分布的基础上,综述了温度、降水、大气CO2浓度和海拔高度等气候环境因子对陆生植物δ13C的影响以及它们之间的关系,分析了植物δ13C对气候因子变化的响应机理。指出为更准确地认识气候历史,在利用植物碳同位素技术进行全球变化的研究过程中,需要突出C4植物δ13C对气候环境参数的响应研究,加强不同尺度植物δ13C的转换关系以及与相关学科的交叉渗透、探索与多种代用指标和科学方法的联合研究。

Global climate change has been one of the most concerned environmental problems in the world since the 1980s. Since stable carbon composition （δ13C） in plant tissues can record abundant information on cli- mate changes, it has been widely used as an important climate proxy in global change studies and becomes a power- ful tool for obtaining paleoclimate information, understanding paleoenvironment reconstruction and modern climate change, and predicting future climate trends. However, a lot of potential uncertainties have always involved in the reconstruction of paleoclimate and paleoenvironment by carbon isotope of the past period sediment or fossils. Among them, the most dominant uncertainty is due to our poor understanding of the relations between carbon isotope ratios of plants and climatic factors and the climatic and environmental significance indicated by modern plant δ13C. This may limit the application of plant δ13C in the study of climatic and environmental changes. Based on the Summary of plant δ13C fractionation and carbon isotope distribution of different photosynthetic plants, the effects of environ- mental factors, e.g. , temperature, precipitation, atmospheric CO2 concentration, and altitude on terrestrial plant δ13C and their relationships were reviewed in this paper, and the response mechanism of plant δ13C to climate chan- ges were also analyzed. Furthermore, the current existing problems and the future prospects in carbon isotope study were discussed. It is pointed out that strengthening some studies such as the response of C4 plants δ13C to climate environmental parameters, the transformation relation of different scale plant δ13C, intersection and permeation of related disciplines, and various proxies and scientific method, will undoubtedly make us have a more accurate un- derstanding of the climate history and eventually broaden the development of the field during the process of global change study by olant carbon isotope techniques.