Oak represents one of the most adaptable and resilient trees on earth and is widely distributed in multiple environments ranging from wet to dry. Japanese oak forests of Fukushima and the northern Kanto area were contaminated with radiocesium (¹³⁷Cs) by Fukusima Dai-ichi nuclear Power Plant accident. ¹³⁷Cs trapped at the surface soil has a deleterious effect on forest ecosystem and poses further threat to humans when it enters the food chain. The uptake of ¹³⁷Cs and other essential nutrients such as nitrogen (N), phosphorus (P) and potassium (K) by plants with the aid of ectomycorrhizal fungi is affected by soil water content. The objective of this study was to evaluate the colonization rate of ectomycorrhiza (CRE) and its impact on nutrients and ¹³⁷Cs uptake pattern by oak (Quercus serrata Thunb.) seedlings at different soil water content levels under greenhouse condition. The result shows that the growth of Q. serrata seedlings increased with increasing soil water content. In addition, the highest CRE was observed in the low water content (LW) and was significantly different from the high water content treatment (HW). The LW treatment showed the highest N and P concentration in leaves and roots although no statistical differences were observed compared to the other treatments. Treatments with ¹³⁷Cs-amended litter showed increased ¹³⁷Cs concentration in the leaves of plants and its leaf per root ratio increased with decreasing soil water content. The results of the present study also suggest enhanced ¹³⁷Cs absorption and translocation into Q. serrata seedlings is with the aid of ectomycorrhizal fungus except for the seedlings in HW.

中文翻译：

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土壤水分条件对外生菌根定植和137 Cs吸收的影响

橡树是地球上最能适应自然和复原力的树木之一，广泛分布在从潮湿到干燥的多种环境中。福岛第一核电站事故使福岛和关东北部的日本橡树林被放射性铯（¹³⁷ Cs）污染。被困在表层土壤中的¹³⁷ Cs对森林生态系统具有有害影响，并在进入食物链时对人类构成进一步威胁。土壤中的水分会影响外生菌根真菌对植物对¹³⁷ Cs和其他必需养分的吸收，例如氮（N），磷（P）和钾（K）的吸收。这项研究的目的是评估外生菌根（CRE）的定殖率及其对养分和营养的影响。温室条件下不同土壤含水量的橡树栎（Quercus serrata Thunb。）幼苗的¹³⁷ Cs吸收模式。结果表明，随着土壤含水量的增加，锯缘草幼苗的生长增加。此外，在低含水量（LW）中观察到最高的CRE，与高含水量处理（HW）显着不同。LW处理显示出叶和根中最高的N和P浓度，尽管与其他处理相比没有统计学差异。用¹³⁷ Cs修正垫料处理可增加¹³⁷随着土壤含水量的减少，植物叶片中的Cs浓度及其每根叶片的Cs浓度增加。本研究的结果还表明，除硬毛中的幼苗外，借助外生菌根真菌可以增强¹³⁷ Cs的吸收和向锯缘香茅幼苗的转运。