利用沉积色素恢复湖泊古紫外强度研究综述

自从南极臭氧空洞被发现以来，平流层臭氧浓度下降导致到达地表的紫外辐射增强的现象引起了人们的广泛关注，目前这一状况还在不断加剧并将在未来很长一段时间里持续下去。为了更好地理解这种现象在长时间尺度上的意义以及合理预测未来地球表面紫外环境的变化以及生态系统的响应过程，科学家开始尝试恢复历史时期地球表面紫外辐射的变化。Scytonemin是蓝绿藻细胞外鞘上的一种抗UV色素，高UV强度照射能够促使细胞合成更多的这种色素以保护细胞免受紫外辐射的伤害，并且这种色素在湖泊沉积物中能够很好地保存。因此，我们可以通过分析不同时间段蓝绿藻细胞的scytonemin含量来反映历史时期湖泊紫外环境的变化。进一步的研究可以推测造成这种变化的原因以及生态系统对这些过程的响应，为预测未来地表紫外环境的变化及生态系统的响应提供合适的理论和证据。

Review on past UVR environment in lakes derived from pigments in sediment

Since ozone hole was observed in South Pole in 1985, the effect of stratospheric ozone depletion on increasing in ambient levels of ultraviolet radiation (UVR) has raised far-ranging concerns. Unfortunately, meteorological and biological monitoring studies are usually too brief to record the magnitudes of past changes in UV radiation fluxes and their effects. In recent years, scientist demonstrated that certain fossil pigments (TScyt) in lake sediments can be used to document historical changes in the UV radiation environment of lakes. These pigments are produced by cyanobacteria when exposed to UV radiation and show sedimentary concentrations that are correlated to the depth of penetration of UV radiation within lakes. Thus, we can use them to reconstruct long-term changes in biological UVR receipt, to provide a context for evaluating the long-term significance of recent changes in ozone column depth. The current researches in this area mainly concentrated in the polar, and the results show that the biological UVR receipt in lakes experienced substantial fluctuations in the historical period.