日本地球惑星科学連合2019年大会

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[J] ポスター発表

セッション記号 A (大気水圏科学) » A-CG 大気海洋・環境科学複合領域・一般

[A-CG37] 北極域の科学

2019年5月30日(木) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:漢那 直也(北海道大学北極域研究センター)、庭野 匡思(気象研究所)、中村 哲(北海道大学大学院地球環境科学研究院)、鄭 峻介(北海道大学 北極域研究センター)

[ACG37-P07] Flood affects vegetation at plant species level to regional level: Arctagrostis latifolia increased one year after flooding in Indigirka lowland, northeastern Siberia

*両角 友喜1,2鍾 仕鴻1新宮原 諒5,1鄭 峻介2鷹野 真也1樊 荣1,2宮本 裕美子2ルスラン シャクマトフ1永井 信3小林 秀樹3鈴木 力英3マキシモフ トロフィム4,6杉本 敦子2,7 (1.北海道大学大学院 環境科学院、2.北海道大学 北極域研究センター、3.海洋研究開発機構、4.寒冷圏生物学問題研究所、5.名古屋大学大学院 環境学研究科、6.北東連邦大学、7.北海道大学 国際連携研究教育局)

キーワード:植生、環境モニタリング、葉面積、洪水、ツンドラ

In June-July 2017, unusual extensive (~10000 km2) and long-time (~2 months) river floods were observed at coastal lowlands in northeastern Siberia. We focused on vegetation covered with dwarf shrub, sparse larch and polygonal wetlands, which were affected by the extreme flooding. We investigated plant species composition and in-situ phenology at site, and clarify the vegetation change after the flood in Indigirka river lowland, eastern Siberia (70oN, 148oE) for 2009-2018 July summer. We also recorded timing of leaf opening (greening) after flooding by digital time-lapse camera (GardenWatchCam, Brinno), and visible-near-infrared band satellite images (Landsat 8 OLI, USGS). In the field, forbs and graminoids (e.g. Arctagrostis latifolia as indicator of disturbance in arctic tundra) were increased among plots after the flood. On the other hand, dwarf shrubs (i.e. Vaccinium vitis-idaea) and moss species (i.e. Hylocomium splendens) were declined. The timing of leaf opening was delayed in the field. Fraction of leaf coverage per plot surface area were estimated from photo images. Leaf coverage on shrub were significantly smaller in 2017 summer (5.6%) than those in 2012-2016 (37%) in the plots (n=3, p < 0.005). Satellite images also supported that the greening of vegetation was delayed, and vegetation cover was declined in the region in 2017. Damaged moss cover and organic layers were remained to be exposed mud / bare soil in August 2018 (1 year after flood). However, leaf covers were even increased in some sedge-wetland plots, because of the increased growth of graminoids (e.g. Arctagrostis latifolia), forbs and sedges. Replacing to more graminoid might affect carbon and energy balances, and even might triggering permafrost thaw in some parts. Therefore, process changing and recovering from flood should be monitored in temporary and spatially multiscale.