切尔诺贝利核事故以来隔离区动物生态的研究概况
Animal Radioecology in the Exclusion Zone Since the Chernobyl Catastrophe
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摘要: 综述了切尔诺贝利核事故以来乌克兰Schmalhausen动物研究所(SIZ)对核工厂周围隔离区(exclusion zone, EZ)的野生动物所进行的长达20年的放射生态学调查研究。基于乌克兰以往鸟类迁移的观察资料，评估了137 Cs和90 Sr在隔离区候鸟体内的含量。而且还选择一些动物物种作为环境状况的标准指示生物，目的是为了阐明：137 Cs在隔离区脊椎动物体内的污染情况；整个第聂伯河流域、基辅行政区和隔离区软体动物贝壳内90 Sr的β活性。结果表明不同物种相对放射性核累积、迁移和累积因素呈有规律的季节性和长期性变化趋势，这些参数的运用可以大大地减少数据的波动和复杂性。直接辐射毁坏森林后，营养链的崩溃和病死树昆虫害虫的爆发导致了其次级生态变化。99%的隔离区并不直接受辐射的影响，人员撤离、农业和森林管理停止以及大规模排除污染是这些区域生态变化的主要因素。在初始变化之后，由于自然资源、捕食者和偷猎者等的限制，隔离区的动物密度和分布达到一个稳定的极限值。 数年前成功地在隔离区引入了一群蒙古野马，该群体保持了稳定增长。重新评估了以前划定的若干自然保护位点目前的保护状况，并提出了建议扩大这些自然保护区的范围等保护措施。Abstract: We review 20 year long investigations by the Schmalhausen Institute of Zoology on radioecological and ecological consequences of the Chernobyl catastrophe for wild animals in the Exclusion Zone (EZ) around the nuclear plant. Using previous observations on bird migrations through Ukraine, we assessed the 137 Cs and 90 Sr carry-out with migrants from the EZ. In addition, we selected animal species as standard indicators of the state of the environment to map: 1) contamination of vertebrates with 137 Cs in the EZ and 2) beta-activity of mollusc shells indicating 90 Sr, in the whole Dnieper drainage area, in the Kiev Administrative Region, and in the EZ. We revealed regular seasonal and long-term trends, relative radionuclide accumulation by different species, transfer and accumulation factors, and used these measurements to diminish the enormous variation and complexity of the data. Secondary ecological changes in forest, devastated by direct irradiation, were caused by the crash of trophic chains and an outbreak of insect pests on dead or sick trees. Ninety-nine percent of the EZ area was not affected directly by irradiation. Ecological changes in this area have been caused by evacuation of the public, cessation of agriculture and forest management, and decontamination on a large scale. After initial changes, animal density and distribution have been stabilized at a limit restricted by natural resources, predators and poachers. A herd of Przewalski horses was successfully introduced into the EZ years ago. We renewed the protected state of nature reserved sites, which existed before, and proposed to expand the area of nature reservation.
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