ビーバー再導入で治水対策　英団体が計画発表

【ロンドンＡＦＰ＝時事】自然保護や歴史的建築物保全に取り組む英慈善団体ナショナル・トラストは20日、イングランド南部の2か所に地域絶滅種であるビーバーを再導入し、治水に役立てる計画を発表した。（写真は資料写真）
　来年初めからのプロジェクトでは、囲いのある敷地２か所に１組ずつヨーロッパビーバーのつがいを放ち、専門家が生息環境の変化を観察する。
　片方の放出地でプロジェクト責任者を務めるベン・イヤードリー氏は、「ビーバーが造るダムは雨の降らない季節に水をためてくれるほか、下流で起こる鉄砲水の緩和に役立ったり、シルトを保持することで土壌流出の軽減や水質改善をもたらしたりする」と述べた。
　かつては英国に生息していたビーバーは、毛皮や肉、じゃ香腺への需要が原因で１６世紀に姿を消した。その後、スコットランド西部などで、人間の管理下で元の生息地にビーバーを再導入する計画が実施されている。
　ビーバーは「天然の土木技師」と呼ばれ、ダムを造ることで、昆虫から野鳥まで幅広い生物を支える湿地環境づくりに寄与する。
　イヤードリー氏は、河川流域にビーバーが生息することで「気候変動や、それによる異常気象に対して、周辺の地形の復元力が高まる」と説明した。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2019/11/21-09:01）

Beavers are to be reintroduced in two parts of Britain as part of plans to help control flooding, the National Trust announced on Wednesday.
The charity, which manages historic properties and countryside, said it aimed to release Eurasian beavers at two sites in southern England early next year.
The dams the beavers create will hold water in dry periods, help to lessen flash-flooding downstream and reduce erosion and improve water quality by holding silt, said Ben Eardley, project manager at one of the sites.
Beavers were hunted out of existence in Britain in the 16th century because of demand for their fur, meat and scent glands.
There have since been several controlled reintroductions of the mammals, including in western Scotland.
Beavers have been described as nature's engineers, whose work can help create wetland habitats to support a range of species from insects to wildfowl.
Beavers in river catchment areas would help make our landscape more resilient to climate change and the extremes of weather it will bring, Eardley said.
He will oversee the reintroduction of one pair of beavers at Holnicote, near Exmoor National Park in southwest England.
Another pair will be released on the Black Down Estate, on the edge of the South Downs on the English south coast.
They will all be introduced in fenced-off woodland areas. Experts will then monitor changes to the habitat that result.
The National Trust is aiming to restore 25,000 hectares (62,000 acres) of wildlife-rich habitats by 2025, amid concern at a decline in species since 1970.
Parts of northern England have been hit by severe flooding in recent weeks, with some areas having their wettest autumn on record, according to the Met Office weather agency.
Eighteen flood warnings were in place on Wednesday morning, with 58 further alerts notifying possible flooding, the Environment Agency said.
As well as prolonged heavy rainfall, building on flood plains, poor flood defences and maintenance of watercourses are among the contributory factors.