It is not only the biologists who are concerned about the gradual expansion of the invasive species. While the presence of certain species is realised by almost everyone, others has not raised public attention yet despite their rapid spreading.
The Common Ragweed (Ambrosia artemisiifolia) is the best known that has turned to be the root cause of nowadays gradually increasing human health problems. The area covered by the species is estimated around 420,000 ha, a figure increasing by about 6% every year according to certain calculations. Approximately 2.5-3 million people are sensitive to the pollen of the plant. In order to eradicate and restrict this species numerous initiations were launched on a national, regional and local level; the land protection and plant protection regulations urge the whole society to take an action.
Much bigger is the number of the species that get less publicity in the daily press. According to a 1998 survey almost 20.6% of the protected grasslands in Hungary - that is roughly 44,000 ha - have been infected with invasive plant species, such as the Giant and Canadian Golden Rod (Solidago canadensis and Solidago gigantea) or the Common Milkweed (Asclepias syriaca). The estimated cost of their eradication exceeds one billion Hungarian Forints. In spite of the facts mentioned above these species appear as imposing garden plants or possible bee pasture plants to install in professional gardening and apiculture periodicals.
What does biological invasion mean and what do we call an invasive species?
Invasive alien species (IAS) are species that following their intentional or unintentional introduction outside their natural habitats are able to establish themselves and to take over the new environment, imposing thereby the ecological equilibrium of native communities to a danger.
These living organisms can originate from any taxonomic unit. It is a well known fact that the invasive species considerably affect the biological diversity of the natural habitats and their surrounding areas, shall they be located within or outside protected areas. These species can cause significant, irreversible environmental and socio-economic damages at the genetic, species and community levels. In spite of the socio-economic problems and the concerns arising in the society, the invasion of the non-indigenous species endangers first of all the biological diversity, turning the phenomena into a problem mainly concerning the nature conservation. The invasion of these species - together with habitat loss and fragmentation - has become one of the major threats to biodiversity.
Their spreading, multiplication and later, possible integration into previously unaffected habitats are facilitated a lot by international trade through relatively more open borders, transport, travelling and healthily developing tourism.
The degree of invasion varies species by species, intentional introductions can occur and the distribution is probably affected by global or local climate changes. Beside the factors mentioned above, human activity in remaking nature has a significant role in every case, as we ourselves create the favourable ecological conditions for the invasive species by certain transformations made in the nature.
Nearly every geographical region fights against its own invasive species, a number of which are problematic to several regions due to their wider tolerance. However it has to be highlighted that each country is exposed to this danger in a different way.
Most endangered are the islands and the ecosystems isolated due to other environmental factors; their power of resistance against invasion is very weak. The level of activity against invasive species, the magnitude of the amount invested into research, the inclination of the government and the sensibility of the society also vary country by country.
While almost each and every country has recognized the danger of invasive species, the lack of legal, economic and other measures intending to eradicate and restrict them had to be realized. Large scale research and eradication programmes have been launched in some countries; in certain regions the invasive species have been selected and determined; whereas there are states where nothing has been done yet.
The professional meeting called "The aggressive adventive species and the nature conservation" was held in Jósvafő, 11-13. March 1998, where the participating botanists and nature conservation specialists summarized their knowledge and nature conservation management experiences relating to the species considered to be the most dangerous on the basis of their dynamics of spread.
The specialists have highlighted, that the effective legislation does not provide an adequate legal basis for the handling of the biological invasion, therefore they judged it necessary to create a law that would firmly restrict the import and the use of these species in forest management, in mine recultivation and in landscaping.
At this meeting the list of the most dangerous species was put together containing 33 adventive and 3 indigenous species (certain conditions can awake invasive characteristics in these later).
a. ) Adventive species
False Indigo (Indigobush)
Canadian Golden Rod
Giant Golden Rod
River Bank Grape
b. ) Native species
The Common Reed
Blackberry Bramble agg.
Rubus fruticosus agg.
This list of species has provided a great help during the net period of professional work, however the freshening of data and its completion has become crucial meanwhile, because during the past 5 years significant Hungarian and international research findings had been accumulated.
The international activity is increasing: the "Day for Biological Diversity" of the Convention on Biological Diversity (CDB) on 22 May focused explicitly on the recognition of the dangers of invasive species. The second intergovernmental conference, the Biodiversity in Europe, was held in February 2002, in Budapest, where Hungary and the United-Kingdom jointly introduced the problem of invasive species. This event served as a preparatory meeting for the sixth Conference of the Parties of the CDB taking place in the same year, where the problem of the biological invasion was a subject of major interest. Many steps have been made forward on this forum; it was revealed for example that the Bern Convention could possibly carry out important tasks and coordination in this field in Europe. The elaboration of the European Strategy on Invasive Alien Species, coordinated by the Bern Convention, was brought into prominence as well. The strategy plan discusses in details the necessary actions to be taken: from the legislation, to the establishment of the adequate organizational background (establishing a biological security institute), to the elaboration of a national/regional/international database and to the promotion of the national co-operation. The strategy plan was adopted at the end of 2003. It is important to mention that it formulates only the general framework and proposals; as the elaboration of the actions in the form of a national strategy is the responsibility of the member states, therefore of Hungary as well.
It is high time to deal with the danger of the aggressively spreading alien species, regarding their so far inexperienced invasion. The need for the transfrontier cooperation superior to political borders has to be particularly highlighted.
The State Secretariat for Nature and Environment Protection of the Ministry of Environment and Water aligning the requirements of the European strategy has begun the collection and classification of the research and handling experiences concerning the invasive species in Hungary and consequently led down the foundation stone of the national strategy.
The publishing of a collection of essays based on the studies of the botanists conducting research on the Hungarian invasive plants is under preparation. In compliance with the objective determined five years ago, beside the popularization of scientific knowledge, the possibilities for the restriction and regulation of the species and the conservation handling experiences of the national park directorates will be presented in the publishing.
However the work cannot be done by that, since the plants presented do not cover the entire range of the dangerous species in Hungary at all. Drawing the attention of the specialists on species about which we hardly know anything yet, it is our explicit intention. We hope that the publishing will incite the birth of researches on invasive species, dissertations or maybe a serious scientific work. The nature conservation seems to have a growing need for such works in the future. Decently informing and mobilize the public is an extremely important, because a complete success against the invasive species can not be achieved without the civil organisations and the private individuals.
Publications related to the topic:
Invasive Alien Species In Hungary (pdf)