Table 1 Description of the sampled trees and monitoring sites.

From: Decadal trends in 137Cs concentrations in the bark and wood of trees contaminated by the Fukushima nuclear accident

Sitea

Species

Age (y)b

DBH (cm)c

137Cs dep.(kBq m−2)d

Sampling year

Bark (whole), wood

Outer bark, inner bark

Site 1 (KU1)

Cedar (Cryptomeria japonica)

52

24.2 ± 7.0

747

2011–20

2012–20

Cypress (Chamaecyparis obtusa)

35

20.1 ± 3.2

694

2012–20

2012–20

Oak (Quercus serrata)

35

16.6 ± 4.8

694

2012–20

2016–20

Site 2 (KU2)

Cedar (Cryptomeria japonica)

66

35.5 ± 7.9

184

2011–20

2016–20

Site 3 (OT)

Cedar (Cryptomeria japonica)

51

27.4 ± 5.6

52

2011–16, 18, 20

2012–16, 18, 20

Oak (Quercus serrata)

52

21.7 ± 5.8

54

2011–17, 19

2015–17, 19

Pine (Pinus densiflora)

52

24.6 ± 6.1

54

2011–16, 19

2012–16, 19

Site 4 (TD)

Cedar (Cryptomeria japonica)

47

25.6 ± 5.2

11

2011–16, 20

None

Site 5 (TB)

Cypress (Chamaecyparis obtusa)

52

23.0 ± 5.6

33

2011–16, 19

2019

Site A1

Pine (Pinus densiflora)

53

26.7 ± 7.1

774

2017–20

2017–20

Chestnut (Castanea crenata)

≈50

25.3 ± 5.5

774

2017–20

2018–20

  1. aSite names in parentheses correspond to those in the study of Imamura et al.31. bTree age as of 2020. cMean ± standard deviation of sampled trees. dInitial deposition density of 137Cs following the Fukushima nuclear accident as of July 2, 2011, estimated by Kato et al.21. DBH, diameter at breast height.
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