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The ambient dose rate (ADR) in a coniferous forest floor contaminated by Fukushima-derived 137Cs was calculated for small temporal scale as a function of depth. The calculated total ADR was statistically evaluated along the soil vertical strata and among the sampling time series. Moreover, the contribution of the forest floor components to the total radiation dose were examined. Accordingly, the litter and fragmented organic layers accounted for about 58 to 96% (mean 77 ± 14%) of the ambient dose, indicating the organic layer is a chief sources of external radiation exposure, and an important radiological soil section. [ABSTRACT FROM AUTHOR]

Background and aims: Elevated ozone (O3) decreases nitrogen derived from rhizodeposition (NdfR). However, the changes in the partitioning of NdfR in soil N pools due to O3 remain unclear. The aims of this study were to investigate the contribution of NdfR to different soil N pools and its response to elevated O3 conditions.Methods: Spring wheat was labeled with 15N-urea using a split-root technique under ambient (~40 ppb) and elevated O3 treatments (60 ± 5 ppb and 110 ± 5 ppb) in open-top chambers. Mineral-N, microbial biomass (MB)-N and fixed ammonium (FA)-N in rhizospheric soils were analyzed.Results: N rhizodeposition contributed 12-33% of mineral N, 10-14% of FA-N and 6-16% of MB-N under ambient O3. Elevated O3 significantly decreased mineral-15NdfR and increased FA-15NdfR but had no significant influence on MB-15NdfR. The decrease in mineral-NdfR was likely due to the decrease in rhizodeposition inputs and the increase in FA-NdfR.Conclusions: Our results showed that elevated O3 altered the contribution of NdfR to soil N pools. The present study increases our understanding of the dynamics of NdfR and the changes in soil N cycling induced by projected future O3 levels. [ABSTRACT FROM AUTHOR]

Key message: Thinning resulted in evapotranspiration decrease and caused the relative contributions of each component to evapotranspiration to become very close. Abstract: To increase the understanding of forest management to control water cycles, we examined the effect of 50% strip thinning on evapotranspiration (ET) and its partitioning into canopy interception ( E ), tree transpiration ( E ), and forest floor evaporation ( E ) in a Japanese cypress ( Chamaecyparis obtusa Endl.) plantation. Intensive measurements were employed to monitor each component of ET during the pre- and post-thinning periods. The results showed the annual E was the dominant component of ET followed by E , whereas E was the smallest component in both periods. Thinning has significant impact on the process of ET partitioning. In such that it decreased from 42.3 to 33.7% in E /ET and from 45.0 to 34.9% in E /ET, and increased from 12.7 to 31.4% in E /ET on an annual scale. The relative contributions of each ET component to the whole ET became more or less the same after thinning. Additionally, the monthly E / P had relative stable values in both pre- and post-thinning periods, contributing significantly to the ET/ P during heavy rainfall conditions. After thinning, ET decreased by 21.4% from 629.3 to 494.8 mm during the growing season and by 20.4% from 979.8 to 780.1 mm at the annual scale, demonstrating that thinning results in an increase in water availability in the forested watershed. This study can improve the understanding of forest water budget in response to thinning and aid in development of appropriate forest management practices accordingly. [ABSTRACT FROM AUTHOR]