The deposition of radionuclides from Chernobyl to a forest in Belgium

Cs-137 distribution in forest floor and surface soil layers from two mountainous regions in Bulgaria

“…On one hand it restricts the radioactive deposition and on the other hand it participates in humus formation and in biological transfer of radionuclides. Ronneau et al (1987) underlined the important role of forests in retention of radioactive fallout. A confirmation for this hypothesis is the estimated factor of accumulation (FA).…”

“…The Factor of accumulation [FA] was used for determination of the influence of forest vegetation on the radiocesium contamination in mineral soil (Ronneau et al, 1987). In our study we used the soil depth 0-15 cm and the estimates are done as a ratio between the sums of contamination densities for the different soil depths D1 + D2 + D3.…”

Temporal changes in radiocesium deposition in various forest stands following the Fukushima Dai-ichi Nuclear Power Plant accident

“…In the mature cedar stand, the measured 137 Cs inventory for the first sampling period was greater than that determined by the airborne measurement of radioactivity (Third Airborne Monitoring Survey; MEXT, 2011b), although high canopy interception rates (>70%) for atmospheric 137 Cs deposited to coniferous canopies have been reported previously (Bunzl et al, 1989;Melin et al, 1994;Ronneau et al, 1987;Sombr e et al, 1994;Kato et al, 2012). The measured 137 Cs inventories for the mature cedar stands had significant variations (Table 4), indicating that the spatial variability of 137 Cs deposition on the forest floor was relatively high.…”

“…An initial canopy interception rate of >90% was reported for radiocesium in 41-y-old Japanese cedar stand (C. japonica) with a stand density of 1300 ha -1 and a 40-y-old cypress stand (Chamaecyparis obtusa) with a stand density of 2500 ha -1 . Ronneau et al (1987) studied the deposition of Chernobyl-derived 137 Cs onto a pine forest in the east of Belgium. They reported a very effective retention of the deposited 137 Cs by plant foliage, and the initial 137 Cs interception by pine canopies was estimated to be 79% of the atmospheric input.…”

Vertical distribution and bioavailability of 137Cs in organic and mineral soils

“…Due to the high interception potential, more 137 Cs was deposited in coniferous forests than in adjacent grassland areas (Bunzl et al, 1989). The canopy in coniferous stands retained most of the 137 Cs that was initially deposited (Ronneau et al, 1987;Melin et al, 1994). The radiocesium transfer from the vegetation to the soil surface occurred through stem flow, litter fall, and leaching with a temporal delay of many months or years (Bunzl et al, 1989).…”