Alien as a Cost Factor
Like the coypu or the Asian tiger mosquito, the Common Ragweed is not indigenous to Europe, but an alien invader. It looks quite harmless, however, its flowers are very potent: the pollen of the Common Ragweed (Ambrosia artemisiifolia) causes allergies and prolongs the affliction season for people allergic to plant pollen. The health system has to bear the treatment costs as well as the resulting absenteeism from work due to ill health. A study compiled by the Helmholtz Centre for Environmental Research - UFZ and the AllergieZENTRUM of the Ludwig Maximilians University in Munich for the first time provides an estimate of these costs totalling approximately 200 million to more than 1 billion Euro per year for the whole of Germany, depending on the scenario.
The Common Ragweed originally comes from North America and therefore is classified as belonging to the group of non-indigenous species, also called invasive exotics or aliens. Ever since people travel, they either consciously or unconsciously carry along with them animals and plants. Yet the problems connected with this, such as the spreading of diseases, damages to agriculture and ecosystems, as well as the costs incurred by counteractive measures have been made the subject of research only for the past few decades. The more globalised our world economy becomes and the more wares are transported across large distances, the more frequently this will result in the transportation of invasive exotics.
Although many species are harmless, even small plants or animals can cause great harm. For instance, since the 1990s, the Asian tiger mosquito (Stegomyia albopicta), which, in contrast to European mosquito species, can transmit also dangerous tropical diseases such as dengue fever, has slowly been advancing northwards across Europe. Therefore, knowledge of invasive species is urgently required. Within the EU project DAISIE (Delivering Alien Invasive Species Inventories for Europe), more than 100 European scientists have compiled a kind of inventory. Now, after three years, this has been comprehensively updated. "Over the course of the past few months, both detailed information on 1,000 new species and updates regarding already existing data sets were included", explains Dr Marten Winter from the UFZ. The database contains information on a total of 12,177 species.
"With a reach well beyond the borders of Europe, the DAISIE database portal has evolved to become one of the most important sources of information on non-indigenous species for scientists, conservationists, politicians as well as for people more generally interested in this issue", emphasises Dr Ingolf Kühn, who likewise works at the UFZ. Invasive species are one of many factors that can cause imbalances within an ecosystem. Intact ecosystems generate profit worth billions. Even so, they are often not appropriately taken into account by political processes.
During an international expert forum in Brussels, this discrepancy was recently highlighted by seven European environmental research centres, which have joined forces within the PEER network (Partnership for European Environmental Research). The Helmholtz Association is a member through representation by the UFZ. Ultimately, the same old adage applies also for nature as a whole: a stitch in time can save nine or timely precaution can help to prevent gigantic costs for subsequent measures.