Soil and vegetation radionuclide activity concentrations and calculated dose rates from the Red Forest, Chernobyl, Ukraine, 2016-2017

Data comprise plot details and radionuclide activity concentrations for Sr-90, Cs-137, Am-241, Pu-238, Pu-239 and Pu-240 in ‘grassy’ vegetation and soil. These radionuclide activity concentrations have been used to make estimations of total weighted absorbed doses to grassy vegetation, deciduous trees and bacteria; no dose rate estimates for grassy vegetation have been made for those sites where grassy vegetation was absent.

Radiation from the 1986 Chernobyl nuclear power plant accident killed coniferous trees in a 4-6 km2 area of forest to the west of the power plant. This area is now known as the 'Red Forest’ and it has subsequently regenerated with understorey vegetation and deciduous trees; it is the most anthropogenically contaminated radioactive ecosystem on Earth. In July 2016 a severe fire burnt (to varying degrees) c. 80 percent of the Red Forest; this presented a unique opportunity to study the impact of radiation on the recovery of forest ecosystems exposed to a secondary stressor (fire). To investigate this, in September 2017 the RED FIRE project set up sixty study plots in the Red Forest (in burnt and unburnt areas) with a further nine plots established close to Buriakivka village (approximately 8 km from the Red Forest).

Vegetation samples from each plot were harvested using shears in September 2017. Each sample was sorted into ‘grassy’ and ‘other’ vegetation; these were air-dried (20-25 degrees Celsius) and the grassy vegetation samples homogenised prior to radionuclide analyses.

Soil core samples collected in September 2017 were bulked, homogenised and sub-samples taken for determination of pH and percentage moisture determined by oven drying (approximately 60 degrees Celsius) to a constant mass. The remaining soil sample was used for the determination of radionuclide activity concentrations; prior to analyses, these samples were dried at approximately 80 degrees Celsius.

This work was funded by the NERC, Grant Ref: NE/P015212/1 (RED FIRE: Radioactive Environment Damaged by fire: a Forest In Recovery)

数据包含样地详情以及“草本”植被和土壤中锶-90（Sr-90）、铯-137（Cs-137）、镅-241（Am-241）、钚-238（Pu-238）、钚-239（Pu-239）和钚-240（Pu-240）的放射性核素活度浓度。这些放射性核素活度浓度已用于估算草本植被、落叶树和细菌的总加权吸收剂量；对于无草本植被的样地，未进行草本植被的剂量率估算。

1986年切尔诺贝利核电站事故产生的辐射导致电站西侧4-6平方公里林区内的针叶树死亡。该区域现被称为“红森林”，其后已通过林下植被和落叶树实现再生；它是地球上受人为污染最严重的放射性生态系统。2016年7月，一场严重火灾（不同程度地）烧毁了约80%的红森林；这为研究辐射对遭受二次胁迫因子（火灾）的森林生态系统恢复的影响提供了独特机会。为开展此项研究，RED FIRE项目于2017年9月在红森林（烧毁与未烧毁区域）设立了60个研究样地，并在布利亚基夫卡村（距红森林约8公里）附近增设了9个样地。

2017年9月，使用剪刀采集每个样地的植被样本。每个样本被分为“草本”和“其他”植被两类；样本经风干（20-25摄氏度）处理，草本植被样本在放射性核素分析前进行均质化。

2017年9月采集的土壤芯样经混合、均质化后，取子样用于pH值和含水率测定——含水率通过烘箱干燥（约60摄氏度）至恒重的方式确定。剩余土壤样本用于放射性核素活度浓度测定；分析前，这些样本在约80摄氏度下干燥。

本研究由英国自然环境研究理事会（NERC）资助，grant编号：NE/P015212/1（RED FIRE：火灾损毁的放射性环境：恢复中的森林）