ヨーロッパ の 川 に は 100万 件 以上 の 障壁 が 存在 し て いる
Barbara Belletti1,2, Carlos Garcia de Leaniz3, Joshua Jones4
1Politecnico di Milano, Milan, Italy.
Nature
|December 17, 2020
まとめ
ヨーロッパ
科学分野:
- 川の生態学
- 淡水生物多様性
- 環境科学
背景:
- 川は生態系に不可欠なサービスを提供し 豊かな生物多様性を備えています
- 川の断片化が 生態学的つながりを阻害しています
- 調和したバリアデータがないため,ヨーロッパの河川接続性の評価は制限されています.
研究 の 目的:
- ヨーロッパ全域の流れ障壁の範囲と密度を定量化する.
- 壁の分布に影響を与える要因を特定する.
- 川の回復戦略と政策の実施に情報を提供すること.
主な方法:
- 36カ国の新しい,調和したバリアデータベースの分析
- 川の長さ2,715キロメートルの ウォークオーバーの 標準化調査
- バリア密度の予測要因を特定するための統計モデル化.
主要な成果:
- ヨーロッパには少なくとも120万の流れの障壁があり,平均密度は0.74の障壁/kmです.
- 68%の障壁は小さい (高さ<2m) であり,しばしば見過ごされ,数値は61%も過小評価されています.
- 壁の密度は農業の圧力,川と道路の交差点,地表水の範囲,高さと相関しています.
結論:
- 小規模で見過ごされた障壁は ヨーロッパ全域の川の断片化に大きな影響を及ぼします
- 比較的断片化されていない川の緊急の保護が必要である.
- EUの生物多様性戦略の2万5千キロメートルの目標を達成するために,小さな障壁を認識するパラダイムシフトが不可欠です.
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