.A...j....7(2)-.{..

Size: px

Start display at page:

Download ".A...j....7(2)-.{.."

ことこかわらい
5 years ago
Views:

1 7 2 p Jpn. J. Histor. Bot. * 6000 Masanobu Yoshikawa *: Vegetation Changes during the Last 6000 Years at the Tameike Site of the Musashino Upland, Central Kanto Plain Pollen influx pollen influx Abstract Vegetation changes and human activities around the eastern part of the Musashino Upland during the last 6000 years were reconstructed from plant fossil assemblages and pollen influx at the Tameike Site, and seven vegetation stages were established accordingly. At ca yr B.P., dissected valleys formed drowned valleys around the Tameike Site, and deciduous broad-leaved forests dominated by Quercus subgen. Lepidobalanus flourished. Since ca yr B.P., Castanea forests expanded on the upland with swamp forests in the dissected valleys. At ca yr B.P., the vegetation on the upland changed into evergreen broad-leaved forests dominated by Quercus subgen. Cyclobalanopsis. The pollen influx suggested a decrease of forests by human activities since ca yr B.P. After the Yayoi Period, forests declined gradually and changed into sparse copse at about 1000 yr B.P. Since ca yr B.P., forests on the upland recovered, but changed into sparse forests again after the 14th century, and Pinus forests expanded after that. At the beginning of the 18th century, the shore of the Tameike pond was buried rapidly with domestic garbage, such as edible plants and garden trees. Key Words : Edo, Holocene, pollen analysis, pollen influx, vegetation history pollen influx 1 1 cm Davis, 1967; Tsukada, 1972 pollen influx * Ancient Forest Research, Yamanoshita, Fukuoka-Nagafukuro, Shiroishi , Japan

48 7 2 pollen influx 7 2 1996 I II 7 7-1 7-2 7 1997 7 620 1 20 1606 1989 1997 1457 1460 1572 1590 2500 1 1989 7 a b c JR Fig.

2 pollen influx I II a b c JR Fig. 1 Locality map of the Tameike Site and physiographic scheme of Edo at about 1590 A.D. modified from Suzuki (1989). Locality map: filled area = excavation area of the Subway No. 7 line, stippled area = that of the Prime Minister s official residence. Physiographic scheme: a = plateau, b = swamp, c = natural levee, circle = JR station.

3 a 2 Yu-lYu-u L M U UM Yu-l L M U UMYu-u 10 Tm-a b c d e f g z h i B As-B Tm-c Kg Tm-z Yu-l 2.2 m 3 TM L Yu-l M 140 cm 80 cm L TM cm 2 3 cm 60 cm 1997a 3 Fig. 2 Stratigraphy of the Tameike Site (modified from Yoshikawa (1997a)). See Fig. 3 for legends of the columnar section.

4 b, 1997a a b c d e f g h i j Fig. 3 Geological columnar sections of the Tameike Site (compiled from Yoshikawa (1996b, 1997a)). a = soil, b = herb peat, c = wood peat, d = peaty silt or decomposed peat, e = silt, f = sand, g = gravel, h = wood fossil, i = shell, j = tephra. 1 2 cm TM1 7 Tm-h itm-f g z Tm-g Tm-z Kg Tm-g S-11 Tmh i S-5 S L, 1996b;, 1997 Alnus sect. Gymnothyrsus Magnolia Acer Fraxinus Symplocos Ligustrum 1997 M L U TM1, 1972 NGT-A 75 cm TM1 35 cm Tm-b c d e 4 Tm-e

5 Tm-c As-B Tm-e S-24-7 Tm-b S-24-8c 2050 As-B UM UM A B A TM TM cmtm TM TM6 7 A Tm-a F-Ho B TM2 4 5 NGT-A 20 60cm 1 m 5 6 m cm F-Ho UM TM6 U (A) TM10 pollen influx 1 cm 110 C C 3 pollen influx TM6 TM10 Fig. 4 Variations of ignition loss and sedimentation rates at localities TM6 and TM10.

6 cm cc cc 10%KOH 48%HF ZnBr cm 2 pollen influx 12 µm pollen influx cm 2 L M U (A) L 38 83% 68 14% M 51 78% 64 9% 4 No No. 25 No. 27 U (A) 20% 16 19% 18 1% U (A) U (A) TM6 TM10 Fig. 5 Variations of pollen influx and charcoal fragments at localities TM6 and TM10.

7 U (A) % 5 3% 1997 L 0.54 mm/year M 0.77 mm/year U (A) 1.53 mm/year U (A) 5.52 mm/year 10 5 L M 500 U(A) 650 M U (A) L M U (A) 5 L r = 0.74 F M U (A) 1 % % L M TM6 TM10 Fig. 6 Relationship between ignition loss and pollen influx at localities TM6 and TM10. a 1 TM NGT-A c 1997b 7 TM-I II III IV V TM-I Quercus subgen. LepidobalanusCarpinus Ostrya Castanea Ulmus Zelkova Celtis Aphananthe Juglans Quercus subgen. Cyclobalanopsis TM-II

54 7 2 TM-I NTG-A 1996c Cyperaceae 10 Sparganium Nuphar TM-III Aesculus TM-IV Cryptomeria japonica Abies Tsuga Taxaceae Chephalotaxaceae Cupressaceae Gramineae Typha Sagittaria Oryza TM-V Pinus

8 TM-I NTG-A 1996c Cyperaceae 10 Sparganium Nuphar TM-III Aesculus TM-IV Cryptomeria japonica Abies Tsuga Taxaceae Chephalotaxaceae Cupressaceae Gramineae Typha Sagittaria Oryza TM-V Pinus subgen. Diploxylon cf. Gleditsia IlexCamellia FagopyrumChenopodiaceae Cruciferae Carthamus b. 28 TM-III TM-IV TM6 TM b Fig. 7 Main percentage pollen diagram at localities TM6 and TM10 (made from Yoshikawa (1997b)). Percentages of arboreal pollen are caluculated on total arboreal counts, and those of nonarboreal one on total pollen and spore counts.

9 TM-I TM-II TM-III 2 TM-IIIa TM-IIIb TM-IV 2 TM-IVa TM-IVb TM-V c. U (A) AFR.MY1113 TM10-a11 35 µm 35 µm 3 µm 9 7 µm TM-IV TM-IV TM-IV TM-IV TM-IV TM6 TM10 Fig. 8 Main pollen influx diagram at localities TM6 and TM10, showing annual deposition rates.

56 7 2 U (A) 1 3: 4 7: TM10-a11 AFR.MY 1113 10 µm Fig. 9 Fossil pollen of cf. Gleditsia obtained from layer U (A) of the Tameike Site. 1 3: polar view, 4 7: equatorial view. TM10-a11, AFR.MY 1113. Scale bar = 10 µm.

10 U (A) 1 3: 4 7: TM10-a11 AFR.MY µm Fig. 9 Fossil pollen of cf. Gleditsia obtained from layer U (A) of the Tameike Site. 1 3: polar view, 4 7: equatorial view. TM10-a11, AFR.MY Scale bar = 10 µm. TM-I II IIIa IIIb IVa IVb V 7 TM-I II 4000 II III 3200 IIIa IIIb 2600 III IV 2000 IVa IVb 1000 IV V Tm-g S- 11 Tm-z Kg L , TM- IIIb Tm-g 2600, 1994;, , L 2000

11 M 1000 TM6 NGT-A M 1997 Cyperus Scirpus Carex Eleocharis, M As-B As-B, 1986, 1988, 1997c 14 U (A) , , a, 1989 F-Ho U (B), 1996, ,000 12,000 PE HE

12 I II pp., 304 pp. 7 Davis, M. B Pollen accumulation rates at Rogers Lake, Connecticut, during late- and postglacial time. Review of Paleobotany and Palynology 2: II No. 7: I pp : No. 18: II pp 1997 II , II pp II pp Tsukada, M The history of lake Nojiri, Japan. Transactions of the Connecticut Academy of Arts and Sciences 44: a b c a II b II c , :

ラグナNo15.indb

ラグナNo15.indb LAGUNA 15 1 12 2008 12 LAGUNA 15 p.1 12 2008 1 Pollen assemblage changes in the Holocene in the area of Izumo Plain Lake Shinji examples from Lake Shinji and Lake Jinzai Sayuri Kawai 1 Abstract: The vegetation