The Minister of the Environment approved the strategic document according to which work will be continued on removal of invasive species of hogweed. The Management plan for invasive species of hogweed presents a thorough overview of the biology of hogweed species and on how this species reached Estonia. It also analysed the work done so far and the database on which management has been done. The Management plan has an Annex – guide for controlling invasive hogweed species, giving a thorough overview on how to protect oneself from the poisonous juice of this plant, at the same time effectively removing hogweeds. The Management plan is also annexed with a monitoring guide on invasive species. The approved plan states the expected working volumes of the next five years, as well as the budgets. In 2011, a two-year procurement is planned to be announced for the removal of hogweed from an area of 1473 ha. “Removal of hogweed started in 2005 with a modest removal on 235 ha; this area has increased year after year due to both larger removal capacity and the discovery of new colonies,” Merike Linnamägi, Chief Specialist of the Nature Conservation Department of the Ministry of the Environment said. “From this year, the fight against hogweed is planned to be intensified along with removal from a significantly larger area,” she noted. From the point of view of nature conservation, hogweed needs to be removed, since this invasive species takes over new areas successfully and grows in dense colonies. However, in a dense hogweed colony, our domestic plants will not survive. “Regardless of large protection works, hogweed has not been destroyed in Estonia so far,” Linnamägi said, specifying that invasive species will not perish easily since the seed bank in the soil is extensive and remains active in there for almost seven years. In a dense hogweed colony, each square meter has 12,000 seeds. ”In order to get rid of a colony, all plants growing there have to be controlled over a period of 7 years, and additional checks should be made in the following years, just to be sure,” she noted. Control measures must be careful – an average plant produces 20,000 seeds by autumn, but the record is more than 100,000. Thus, ripening and falling of seeds from even one plant is a major setback for many years. Hogweed also needs to be controlled since it is dangerous to human health. If the juice comes into contact with the skin, large blisters will form under the UV radiation in sunlight. In especially serious cases, the blisters may form again at the same spot next year. “In relation to the fact that in many areas hogweed has been controlled successfully for years and the colonies have been weakened, we would like to emphasise to land owners that getting rid of hogweed should also be in their own best interests,” Linnamägi stated, specifying that in the future, land owners will certainly have a bigger responsibility in fighting with this plant. The control of hogweed is one of the most voluminous nature protection works in Estonia. It takes place in May and June in hogweed colonies all across Estonia. As a result of the procurement announced last year all over Estonia, 35 contracts for services were entered into and control measures took place on 1173 hectares. Control measures cost approximately EEK 4.8 million, which was funded from the European Regional Development Fund. The largest of the hogweed colonies repelled in 2010 were in Härjanurme Village in Jõgeva County, Sigula and Liivi villages in Harju County, Viiratsi and Polli rural municipalities in Viljandi County and Haeska village on Saaremaa. Both giant hogweed and Sosnowskyi’s hogweed come from the Caucasus. Giant hogweed was spread in the world in the 19th century as a decorative plant. These introduced species reached Estonia in the middle of the 20th century when they were promoted as valuable silo and honey plants. The Management plan for hogweed is available at www.envir.ee/95541. |
