The Ministry of Economy and Sustainable Development has signed a contract with the European Commission for the project entitled “LIFE CONTRA Ailanthus”,
which plans to establish control over the invasive plant species, Tree of Heaven. The project is valued at HRK 19.4 million, with 60% co-financed by the European Union.
“The EU Biodiversity Strategy to 2030 has set the target of reducing the number of species threatened by invasive alien species by 50%. This demands great efforts and numerous activities in the coming period. Invasive species have a negative impact both on biodiversity, and also on human health and the economy. The Tree of Heaven is one such species, and its removal from the area included in this project will be a direct contribution to conserving the natural and cultural heritage of Dalmatia. We are proud that this project was conceived and prepared under the guidance of the Ministry of Economy and Sustainable Development, and that it passed through independent review and assessment among the more than 400 project applications in the LIFE 2019 call, to be among the 10% of projects approved for financing,” stated Minister of Economy and Sustainable Development, Dr. Tomislav Ćorić.
The project is financed through the LIFE Programme, an instrument of the European Union intended for financing activities in the field of environmental protection, nature conservation and climate. The project will be implemented by the Department for Environmental and Nature Protection of the Ministry of Economy and Sustainable Development, and the project activities will unfold over the next four and a half years.
“Invasive alien species are among the main threats to biodiversity. Some 900 alien species have been recorded in Croatia to date, and some of these are invasive. There are currently 66 invasive alien species that are a cause for concert in the EU, and of these 23 are present in Croatia. The Tree of Heave is one of them,” stated Dr. Aljoša Duplić, head of the Department for Environmental and Nature Protection of the Ministry of Economy and Sustainable Development. He added, “It is characterised by exceptionally rapid growth, am ability to adapt to different ecological conditions and a high capacity for reproduction and spreading. For example, one mature female tree produces 325,000 winged fruits each year, and these are easily carried long distances by wind and water. Unfortunately, this makes elimination and control of this species difficult, long-term and expensive, but necessary. The most cost-effective and efficient way to combat invasive alien species is through education and prevention.”
The project plans to establish control over the invasive tree species Tree of Heaven in the Mediterranean region of Croatia: in two areas included in the ecological network of the Republic of Croatia (HR2000918 Broader area of Krka National Park, and HR2001364 South-eastern part of the Pelješac Peninsula) and in cities with a historical town core (Ston, Mali Ston, Dubrovnik). In addition to the Public Institute of Krka National Park, project partners include the Public Institute for managing protected natural areas of Dubrovnik-Neretva County and the company Vrtlar d.o.o. from Dubrovnik.
“In Dubrovnik-Neretva County, the Tree of Heaven has been recorded throughout the entire county, including the islands and the Pelješac Peninsula. According to the recollections of our elderly residents, this species was brought to Pelješac in about 1900 as an ornamental plant, and it was assumed to have been introduced to the broader area of Dubrovnik-Neretva County in the late 19th century. Along the entire coastal belt, along the Adriatic Highway, and in the towns on the mainland and on the islands, the Tree of Heaven has been observed to be a very aggressive species that suppresses the native species, permanently altering the appearance of the landscape and degrading the stability of the ecosystems, causing immeasurable damages,” stated Marijana Miljas Đuračić, director of the Public Institute for the management of protected natural areas of Dubrovnik-Neretva County.
The Tree of Heaven (Ailanthus altissima (Mill.) Swingle) is native to eastern Asia, and it was transplanted throughout the world in the 18th century as a horticultural species. Today, it is considered one of the most invasive plant species in Europe. The Tree of Heaven supresses the native vegetation and reduces biodiversity, causing damages to agriculture and allergies in humans, and destroys cultural heritage and other structures with its exceptionally strong root system. This species has been included on the list of invasive species of concern in the European Union. In Croatia, the Tree of Heaven is widely distributed, but it particularly threatens the protected habitats and species in the Mediterranean region.
“Conserving the cultural heritage and natural beauty of our country should be the task of us all, as these features shape our identity and our daily lives. We have a large number of horticultural experts, and a strong team for implementation of this project, so we are expecting successful results,” stated Alma Majstorović, director of the public landscaping and horticulture company Vrtlar d.o.o. from Dubrovnik.
The main expected results of the project “LIFE CONTRA Ailanthus” is an improved conservation status of the Natura 2000 habitat types, preserved cultural heritage, preventing the further spread of this invasive alien species, and development of a national protocol.
The Tree of Heaven is an issue in Krka National Park, which is based on the phenomenon of travertine barriers. Due to previous experience with the removal of Tree of Heaven on experimental plots, the Public Institute of Krka National Park will continue with its removal through this project. The aim is to find the most effective method for its removal and for long-term monitoring and management to achieve control over this species. With the aim of long-term and sustainable management of the travertine barriers at Skradinski buk, in 2017, the Public Institute of Krka National Park began implementation of the interdisciplinary scientific project “Management and maintenance of microvegetation at Skradinski buk – development of a multi-criteria model for sustainable management”.
“At that time, an experimental plot covering 8000 m2 was selected at Skradinski buk. All the vegetation in this plot was recorded and inventorised, and then the Tree of Heaven was removed. After removal of the Tree of Heaven, the old watercourses were again reactivated, and on these watercourses, we continued to monitor travertine growth, the dynamics of forming new plant and animal communities necessary for travertine growth, and the physico-chemical parameters of the water. The data we obtained also ready tell of the importance of long-term sustainable management of microvegetation. This project included a large number of scientists from different fields, and has already resulted in a number of expert papers published,” concluded Nella Slavica, director of the Public Institute of Krka National Park.
