Spatial distribution of 137Cs concentrations in mushrooms (Boletus hiratsukae) and their relationship with soil exchangeable cation contents
Spatial distribution of 137Cs concentrations in mushrooms (Boletus hiratsukae) and their relationship with soil exchangeable cation contents
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DOI：
10.1016/j.jenvrad.2020.106364
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发表时间：
2020-10-01
影响因子：
2.3
通讯作者：
Ota, Yuko
中科院分区：
文献类型：
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作者：
Komatsu, Masabumi;Suzuki, Narimi;Ota, Yuko
据报道，野生蘑菇中放射性铯（Cs-137）的活性浓度因物种、属或生态类型而异。此外，同一地区同一物种间的浓度也存在波动。因此，我们研究了野生蘑菇的Cs-137浓度是否存在(1)空间偏置，或(2)受土壤中Cs-137或交换态钾浓度的影响。我们在日本筑波的喜马拉雅雪松林中设置了两个相隔300米的调查地块，在福岛核电站事故后，大约30 kBq/m(2)的Cs-137沉积在那里。从这些样地中，我们收集了共同发生的菌根物种平松菌（Boletus hiratsukae）的子实体（产生孢子的真菌结构）以及下面的土壤。两样地子实体中铯-137的平均含量差异显著，但土壤中铯-137的含量差异不显著。两试验点有机层Cs-137浓度存在显著的空间自相关性，而子实体Cs-137浓度不存在显著的空间自相关性。因此，同生平杉Cs-137浓度的变化不能用空间偏差或土壤放射性来解释。土壤交换态钾浓度与子实体中铯-137含量呈负相关。结果表明，野生蘑菇对Cs-137的吸收会受到周围土壤交换性钾竞争效应的抑制。
The activity concentrations of radiocesium (Cs-137) in wild mushrooms are reported to vary according to species, genus or ecological types. In addition, the concentration fluctuates among the same species collected within the same area. Therefore, we investigated whether the Cs-137 concentration of wild mushrooms would be (1) spatially biased, or (2) influenced by the Cs-137 or exchangeable potassium concentrations in the soils below. We set two survey plots 300 m apart in a Himalayan cedar forest in Tsukuba, Japan, where ca. 30 kBq/m(2) of Cs-137 was deposited after the Fukushima Nuclear Power Plant accident. From these plots, we collected fruit-bodies (fungal structures for spore production) of co-occurring Boletus hiratsukae, a mycorrhizal species, as well as from the soil below. The mean Cs-137 concentrations in the fruit-bodies were significantly different between the two plots, but no difference was observed in the soil Cs-137 concentration between the plots. Significant spatial autocorrelation was observed in the Cs-137 concentration in the organic layer for both sites, but no significant spatial autocorrelation was observed in the Cs-137 of fruit-bodies. Therefore, the variation in the Cs-137 concentrations of cooccurred B. hiratsukae was not explained by spatial bias or radioactivity in the below soil. In contrast, the exchangeable potassium concentration in the soil was negatively correlated with the Cs-137 in the fruit-bodies. Our results suggest that the Cs-137 absorption of wild mushrooms would be suppressed by the competitive effect of exchangeable potassium in the surrounding soils.