Rozema Jelte, Boelen Peter, Blokker Peter
Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands.
Environ Pollut. 2005 Oct;137(3):428-42. doi: 10.1016/j.envpol.2005.01.048. Epub 2005 Apr 21.
Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to experimentally varied UV-B through supplementation or exclusion. In supplementation studies comparing ambient and above ambient UV-B, no effect on growth occurred. UV-B-induced DNA damage, as measured in polar bryophytes, is repaired overnight by photoreactivation. With UV exclusion, growth at near ambient may be less than at below ambient UV-B levels, which relates to the UV response curve of polar plants. UV-B screening foils also alter PAR, humidity, and temperature and interactions of UV with environmental factors may occur. Plant phenolics induced by solar UV-B, as in pollen, spores and lignin, may serve as a climate proxy for past UV. Since the Antarctic and Arctic terrestrial ecosystems differ essentially, (e.g. higher species diversity and more trophic interactions in the Arctic), generalization of polar plant responses to UV-B needs caution.
自1974年以来，南极平流层臭氧每年都会出现消耗现象，导致紫外线B辐射增强。自1990年以来，北极也观测到了臭氧消耗现象。预计到2050年臭氧会恢复，但目前尚无恢复迹象。在此，我们综述了极地植物对通过补充或排除紫外线B而实验性改变的紫外线B的反应。在比较环境紫外线B和高于环境紫外线B的补充研究中，对生长没有影响。在极地苔藓植物中测量到的紫外线B诱导的DNA损伤，会在夜间通过光复活作用修复。在排除紫外线的情况下，接近环境水平的紫外线B条件下的生长可能低于低于环境紫外线B水平时的生长，这与极地植物的紫外线反应曲线有关。紫外线B屏蔽箔也会改变光合有效辐射、湿度和温度，并且紫外线与环境因素之间可能会发生相互作用。太阳紫外线B诱导的植物酚类物质，如花粉、孢子和木质素中的酚类物质，可能作为过去紫外线的气候指标。由于南极和北极陆地生态系统本质上不同（例如，北极的物种多样性更高，营养相互作用更多），因此在概括极地植物对紫外线B的反应时需要谨慎。
