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10 2 p. 67 79 2001 10 Jpn. J. Histor. Bot. 1 2 3 4 5 6 Yaeko Igarashi 1, Tsuneo Igarashi 2, Kunihiko Endo 3, Osamu Yamada 4, Mitsuhiro Nakagawa 5 and Mari Sumita 6 : Vegetation history since the Late Glacial of Habomai Bog and Ochiishi Cape Bog, Nemuro Peninsula, eastern Hokkaido, north Japan Ko-c 2, Ko-d 1 Ta-c 1 Maf 1 4 Ko-c 2 Ta-a Ta-c 1 2 12,000 yr B.P. 12,000 11,000 yr B.P. 11,000 10,000 yr B.P. Younger Dryas 10,000 yr B.P. 7000 yr B.P. 5200 yr B.P. Quercus Loc. 1 Loc. 2 4600 yr B.P. Quercus Betula Alnus 2500 yr B.P. Loc. 1 Loc. 2 Abstract Vegetation history since the Late Glacial was reconstructed by means of pollen analysis and radiocarbon measurement for sediments obtained from Habomai Bog and Ochiishi Cape Bog, Nemuro Peninsula, eastern Hokkaido. Four tephra layers, Ko-c 2, Ko-d 1, Ta-c 1, and Ma-f 1, were discriminated in Habomai Bog in the descending order. Two layers, a mixed one of Ko-c 2 and Ta-a and one of Ta-c 1, were also discriminated in Ochiishi Cape Bog. In Habomai Bog, high bog has developed since 12,000 yr B.P. Taiga composed mainly of Larix gmelinii with Picea jezoensis and/or Picea glehnii and a few Abies sachalinensis and Pinus pumila was distributed between 11,000 and 12,000 yr B.P. Between 10,000 and 11,000 yr B.P., open Larix taiga was distributed under an extremely cold and dry climatic condition. We named this period Habomai Stadial, which probably correspond to the Younger Dryas. After disappearance of Larix gmelinii at 7000 yr B.P., Picea jezoensis and/or Picea glehnii survived there till 5200 yr B.P. A broad-leaf forest composed mainly of Quercus was established at 5200 yr B.P. and has existed there to the present. The dry condition caused by the strong local wind prohibited the distribution of conifer trees. In Ochiishi Cape Bog, peat has been deposited since 4600 yr B.P. A Picea glehnii forest mixed mainly with Abies sachalinensis and Quercus has developed around the bog till present. Fluctuations in forest components around the bog might be caused by changes of the underground water level. Key words: Habomai Bog, Ochiishi Cape Bog, pollen analysis, tephra, vegetation history 1 001-0039 39 3 Earthscience Co.Ltd, North 39, West 3, Kita-ku, Sapporo 001-1139, Japan 2 061-1134 3-7-5 Koyocho 3-7-5, Kita-hiroshima, Hiroshima 061-1137, Japan 3 156-8550 3-25-40 Dept. of Geosystem Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan 4 603-8047 Kyoto Sangyo University, Kita-ku Kamigamo Motoyama, Kyoto 603-8047, Japan 5 060-0810 10 8 Dept. of Earth & Planetary Sciences, Hokkaido University, North 10 West 8, Sapporo 060-0810, Japan 6 Dept. Volcanology & Petrology, GEOMAR Research Center for Marine Geoscience, Wischhofstr. ID-24148 Kiel, Germany

68 10 2 30 20 40 m, 1997, 1984;, 1966 1943 1991 10 32 m 45 m 10 15 m 1 2 m 10 30 cm, 1959;, 1958 1, 1979;, 1992 30 1991 2 5.3 C 8 17.1 C 5.9 C 1035.4 mm WI 1949 45.3 C 46.8 C, 1991 1997 WI 3 5.6 C A Loc. 1 2 5 B Loc. 1 Loc. 2 Fig. 1 Location map of the study areas. A: Habomai Bog. Loc. 1: sampling site, 2 5: measuring points of peat thickness. B: Ochiishi Cape Bog. Loc. 1, Loc. 2: sampling sites, broken line: wooden path, : Ochiishi Cape lighthouse.

69 WI 45 C 1 Alnus hirsuta Betula ermanii Quercus crispula, 1942 Alnus japonica 5 50 160 cm 1A 3 km 1 km 300 ha, 1999 35 45 cm 30 45 cm Myrica gale var. tomentosa Empetrum nigrum var. japonicum Ledum palustre ssp. diversipilosum var. nipponicum Vaccinium vitis-idaea Vaccinium uliginosum Vaccinium oxycoccus Drosera spathulata Sanguisorba tenuifolia var. alba Carex augustinowiczii Sphagnum Plagiochila Lysichiton camtschatcense 2 46 m 1300 m 300 m 1.3 1.5 m Picea glehnii Abies sachalinensis, 1999 1943, 1993 nutrient rich, 1994, 1943 Rhododendron lapponicum subsp. parvifolium Saxifraga bracteata Coptis trigolia Carex middendorffii Eriophorum vaginatum 1936 Loc. 1 N43 21, E145 45 10, 33 m 200 cm 1A Loc. 1 Loc. 2 2 1B Loc. 1 N43 10 54, E145 31, 46 m 150 m Loc. 2 N43 9 55, E145 30 50, 46 m 14 C Loc. 1 2 3 5 cm 1 KOH HF ZnCl 2 Ericales Myrica Ilex 200 50 cm Ta-a Ta-b Ko-c 1 Ko-c 2 Ko-d 350

70 10 2 14 C Table 1 Radiocarbon ages of peat from Habomai Bog and Ochiishi Cape Bog Sampling site Material Depth 14 C age Calibrated age Laboratory No. (cm) (yr B.P.) (2σ: cal BC) Habomai peat 68 73 2,030 ± 40 146 66 AD 1) KSU-1189 Habomai peat 155 160 10,000 ± 140 10,123 9,021 2) KSU-1190 Ochiichi Cape peat 80 100 3,150 ± 90 1,615 1,147 3) N-6669 Ochiichi Cape peat 122 126 4,610 ± 100 3,614 2,997 4) KSU-1416 Ages 1), 3), and 4) were calibrated using a calibration curve by Stuiver & Pearson (1993), and age 2) was calibrated using a curve by Kromer & Becker (1993). The calibrated age ranges reported here are those yielding 90 99%probability at 2σ. KSU: Kyoto Sangyo University, N: Nishina Memorial (Tokyo)., 1988; 1988;, 1988b;, 1996 1989 EPMA (JEOL JXA8600) 15 kv 1 10-8 A 10 10 µm TiO 2 - K 2 O, 1988 1 160 cm 26 27 cm 1 62 68 cm 2 113 123 cm 3 3 2 Loc. 1 0 130 cm 19 20 cm 1 57 59 cm 2 2 90 110 cm Loc. 2 0 135 cm 20 21 cm 62 65 cm 2 Loc. 1 1 2 2 3 14 C 155 160 cm 10,000 140 yr B.P. 68 73 cm 2030 40 yr B.P. 14 C122 126 cm 4610 100 yr B.P. 80 100 cm 3150 90yr B.P. 1 3 NH-1 NH-2 NH-3 NH-1 13 15 cm 2 3 mm NH-2 20 22.5 cm NH-3 34 40 cm NH-1 1.49841.4960 1.5035; 1.4977 1.5009 1.4987 1.4963 1.5026 NH-2 1.4992 1.4983 1.5003 NH-3 1.5009 1.4987 1.5068 NH-1 NH-2 NH-3 26 27 cm 62 68 cm Loc. 1 Loc. 2 2 20 cm 1 60 cm 2 HB-1 HB-8 8 2, 3 2 14 C

71 HB-1 12,000 yr B.P. HB-2 Younger Dryas HB-1 Allerød HB-1 195 169 cm: 12,000 11,000 yr B.P. Larix 37Picea Betula 30 Abies Ulmus Corylus Juglans Cyperaceae 26 96.8 Ericales Ranunculaceae Caryophyllaceae Tubuliflorae Tsuga Selaginella selaginoides HB-2 169 159 cm: 11,000 10,000 yr B.P. Picea Abies HB-1 Ulmus Corylus Juglans Larix 72 Betula Alnus Quercus Cyperaceae 37 350 Sphagnum 51 HB-1 HB-3 159 148 cm: 10,000 9000 yr B.P. Larix Picea 65 Ericales Sphagnum 8 65 Cyperaceae Osmundaceae HB-4 148 123 cm: 9000 7000 yr B.P. Picea Abies Larix HB-3 Ericales Sphagnum HB-5 123 110 cm: 7000 6000 yr B.P. Picea Abies Quercus Alnus Ulmus Juglans Acer Sanguisorba Artemisia Tubuliflorae Osmundaceae HB-6 110-100 cm: 6000 5200 yr B.P. Picea 75 Quercus Osmundaceae 27 81 HB-7 100-37 cm: 5200 700 yr B.P. Picea Quercus 50 Betula Alnus Ulmus Carpinus Juglans Acer Ericales 236 Sphagnum 238 Thalictrum Sanguisorba Artemisia Tubuliflorae Cyperaceae Osmundaceae HB-8 37 0 cm: 700 yr B.P. Quercus Betula Alnus Sphagnum Osmundaceae Myrica Sanguisorba Artemisia Tubuliflorae Gramineae Myrica 67 255 8 HB-1 6 20 82 HB-7, 8 13 51 1) Loc. 1 OC-1 OC-5 5 4, 5 OC1-1 135 112 cm: 4700 3900 yr B.P. Picea 55 Quercus 30 Sphagnum 40 OC1-2 112 48 cm: 3900 2000 yr B.P. Picea Quercus 43 Betula Alnus Ulmus OC1-1 Abies Thalictrum Leguminosae Tubuliflorae Ericales OC1-3 47 32 cm: 2000 700 yr B.P. Picea Abies Ericales Sphagnum OC1-4 32 18 cm: 700 250 yr B.P. Picea Abies Ericales Sphagnum Coptis Artemisia Gramineae OC1-5 18 0 cm: 250 yr B.P. Picea Abies Ericales Myrica Sanguisouba Geranium Tubuliflorae Lilium Gramineae 5 80 OC1-2 12 47 2) Loc. 2 OC2-1 OC2-4 4 6, 7 OC2-1 146 108 cm: 4700 3900 yr B.P. Picea 70 90 Osmundaceae OC2-2 108 50 cm: 3900 2000 yr B.P. Picea Abies Quercus Betula Alnus Osmundaceae Ericales Myrica Sanguisorba Leguminosae Tubuliflorae OC2-3 50 20 cm: 2000 250 yr B.P. Picea Abies Betula Quercus Ulmus Myrica Sanguisorba Tubuliflorae

72 10 2 Fig. 2 Arboreal pollen (except shrub) diagram since Late Glacial from Habomai Bog. Cyperaceae Graminea OC2-4 20 0 cm: 250 yr B.P. Picea Abies Betula Quercus Ericales Myrica 4 90Loc. 1 OC2-2 OC2-3 12 54 3 NH-1 1694 Ko-c 2, 1981 1.4985, 1.4977 1.5034 NH-2 1667 Ta-b, 1981 1.4989 1640 Ko-d, 1981 Ko-d 1 1.4992 NH- 3 Ta-c 1 1.5021, 1.4993 1.5056 2280 90 yr B.P.;, 1971 Ta-c 1, 1988b;, 1988 110 120 cm, 1972 Ma-f 1 6460 130 yr B.P.; Katsui et al., 1975 1 1739 Ta-a, 1981 Ko-c 2 2 Ta-b Ta-c 1 2 Ta-c 1 NH- 1 1 NH-3 2

73 100 Fig. 3 Shrub, non-arboreal pollen and spore diagram since Late Glacial from Habomai Bog. : over 100%. Kudo, 1927 Quercus Ulmus Juglans, 1992;, 1989, 1924;, 2000 Larix, 1970 Larix gmelinii, 1924 Picea Picea jezoensis Pinus Abies Pinus pumila Alexandrova, 1982;, 1993; Mikishin & Gvozdeva, 1999 12,000 11,000 yr B.P. HB-1 8 Betula Betula exilis

74 10 2 Loc. 1 4600 yr B.P. Fig. 4 Arboreal pollen (except shrub) diagram since 4600 yr B.P. from Ochiishi Cape Bog Loc. 1. 5 Loc. 1 4600 yr B.P. 100 Fig. 5 Shrub, non-arboreal pollen and spore diagram since 4600 yr B.P. from Ochiishi Cape Bog Loc. 1. : over 100%.

75 Loc. 2 4600 yr B.P. Fig. 6 Arboreal pollen (except shrub) diagram from Ochiishi Cape Bog Loc. 2 since 4600 yr B.P. Loc. 2 4600 yr B.P. 100 Fig. 7 Shrub, non-arboreal pollen and spore diagram since 4600 yr B.P. from Ochiishi Cape Bog Loc. 2. : over 100%.

76 10 2. Fig. 8 Correlation of vegetation history between Habomai Bog and Ochiishi Cape Bog., 1999 Tsuga Ulmus Quercus Juglans Tsuga 4 230 km 0.01Igarashi, 1987 HB- 15Tsuga Tsuga 4 km, 1988a, 19931 Tsuga Quercus, 1968;, 1986 11,000 10,000 yr B.P. HB-2 HB-1 Cyperaceae Sphagnum HB-1 Quercus Younger Dryas, 1974;, 1964;, 1965, 1980 12,000 10,000 yr B.P.; 1993; Igarashi, 1996 HB-1 Allerød 10,000 9000 yr B.P. HB-3

77 Ericales Sphagnum 7000 yr B.P. 8000 yr B.P., 1993 10009000 7000 yr B.P. HB-4 HB-3, 1998 7000 6000 yr B.P. HB-5 Quercus Quercus 8000 yr B.P., 1986 1000 Quercus 2000, 1993 Quercus Sphagnum Osmundaceae Ma-f1 6000 5200 yr B.P. HB-6 Osmundaceae HB-7 5200 700 yr B.P. Quercus QuercusBetula Alnus Ulmus Acer Ericales Sphagnum 7 km 1986 Quercus 5000 700 yr B.P. HB-8Quercus Betula Alnus SphagnumMyrica Ericales Gramineae 4600 Picea Loc. 1 Loc. 2 4600 yr B.P. 8 Loc. 1 Quercus Betula Alnus 3900 yr B.P. OC1-1 OC2-1 1999 Loc. 1 Ericales Loc. 2 Osmundaceae 5200 yr B.P. 3900 2000 yr B.P. OC1-2 OC2-2Loc. 1 Loc. 2Quercus 2300 yr B.P. 2 Loc. 1 Ericales Loc. 2 Osmundaceae Ilex Ericales Myrica Tubuliflorae 2000 250 yr B.P. Loc. 1 Loc. 2 Loc. 1 2000 700 yr B.P. OC1-3 Quercus Betula Alnus Sphagnum 700 250 yr B.P. OC1-4 Quercus Coptis Gramineae Loc. 2 2000 250 yr B.P. OC2-3 Loc. 1 250 yr B.P. OC1-5 OC2-4 Loc. 1 Loc. 2 Quercus Loc. 1 Ericales Myrica Gramineae Loc. 2 Ericaceae Myrica WI

78 10 2 WI 47.4 C 50 km 2000 Quercus WI 8000 yr B.P. Quercus, 1986 WI 5200 yr B.P., 1982, 1994 5200 yr B.P. Quercus 12,000 yr B.P. 7000 yr B.P. 5000 Younger Dryas 7000 yr B.P. 1000 Quercus 5200 yr B.P. 4600 yr B.P. 5200 yr B.P. 14 C EPMA Alexandrova, A. N. 1982. Pleistocene of Sakhalin. 190 pp. Publishing House NAUKA, Moscow. 1988a 15,000 60 62 A 61302084 45 52 1996 108 1989 98: 506 510 1988b 78 79 1992 49: 336 362 1994 41119 1997 1994 1995 3 14 1959 5 1 40 pp. 1986 38: 266 270 Igarashi, Y. 1987. Pollen incidence and wind transport in central Hokkaido (II). Research Bulletins of the College Experiment Forests, Hokkaido University 44: 477 506. 1989 41: 36 41. 1993 3 21 Igarashi, Y. 1996. A Lateglacial climatic reversion in Hokkaido, northeast Asia, inferred from the Larix pollen record. Quaternary Science Reviews 15: 989 995. 1998

79 48: 231 244 1993 32,000 32: 89 105 2000 109: 165 173 Katsui,Y., Ando, S. & Inaba, K. 1975. Formation, and magmatic evolution of Mashu Volcano, east Hokkaido, Japan. Journal of the Faculty of Science, Hokkaido University, Series IV, 16: 533 552. 1981 Disaster Mapto Hazard Map 23 29 No. A-56-1 1949 17 36 pp. 1974 ice-wedge cast 83: 48 60 Kromer, B. & Becker, B. 1993. German oak and pine 14 C calibration, 7200 9400 BC. Radiocarbon 35: 125 135. 1924295pp. Kudo, Y. 1927. Ueber die Pflanzengeographie Nordjapans und der Insel Sachalin. Österreichische Botanische Zeitschrift 76: 307 311. 1986 5 No. 1: 3 22 Mikishin, Y. A. & Gvozdeva, I. G. 1999. Subfossil spore and pollen complex of norther sakhalin as a basis for reconstruction of the Holocene vegetation. 7-9. Global change studies in the Far East, IGBP IHDP WCRP, Vladiostok. 1958 5 1 30pp. 1968 V 17: 39 51. 1979 74 pp 1991 1991 359 pp 1965 37: 26 30 1980 135 140 1966 326 pp 7 1991 219 pp 1992 246 pp 1999 7: 3 10. 198860 62A 61302084 159 165 1999 114 pp 1982 469 pp 1972 1971 10: 117 123 Stuiver, M. & Pearson, G. 1993. High-precision bidecadal calibration of radiocarbon time-scale, AD 1950 6000BC. Radiocarbon 35: 1 34 1988 No. 9: 9 32. 1964 3: 167 177 1997 1994 1995 3 14 1999 46 113 1942 1 35: 66 101 1943 13: 1 181 1936 2: 7 16 1988 a 1988 1 : 28 1984 36 pp 59 A 58340047 1994 450 pp 1993 40 52. 1970 Larix gmelini 76: 205 214 (2001 9 3 )