Invasive alien species

By combating invasive alien species, the Finnish Transport Infrastructure Agency is enhancing biodiversity in transport infrastructure environments.

Efforts to eradicate giant hogweed in road and railway areas have continued for many years. The measures to combat rugosa rose and garden lupine, which are both widespread in Finland, are prioritised in accordance with the management plan for alien species. Alien species that have been designated or identified as invasive are not planted in transport infrastructure environments.

Timing of vegetation clearing on roadsides can impact the spread of invasive alien species. Flowering lupines are among the plants mowed in this process, which helps to ensure that their seeds are not carried to new locations.

Eradicating invasive alien species, such as lupine or rugosa rose, in areas close to roads and railways is not an everyman’s right and may not be done without a permit. For example, you are not allowed to trespass on motorways or other limited-access roads, and entering railway areas to do vegetation clearing is also prohibited.

If you are planning to eradicate vegetation in these areas, you should first contact Traffic Customer Service for more information on the conditions that apply. Go to Traffic Customer Service.

Rugosa rose

Under the government decree that entered into force in summer 2019, landowners must take measures to combat invasive alien species such as rugosa rose and garden lupine. The three-year transitional period for the ban on breeding rugosa rose set in the decree will end on 1 June 2022.

Rugosa rose is an alien species in Finland and a threat to biodiversity. Even if rugosa rose did not cause any harm in its growth location, its rose hips and seeds can be carried by migratory birds or flowing water over long distances.

In the past, rugosa rose was extensively planted in such places as roadsides because it can tolerate salty road environments and difficult growth conditions.

Questions about rugosa rose

  • In 2019 and 2020, we examined how much we know about the spread of rugosa rose in road and railway areas and produced a preliminary inventory of how extensively and where rugosa rose has been planted. We have continued the inventory work in accordance with the preparation cycle of road maintenance contracts.

    However, there is not yet any comprehensive information on the spread of rugosa rose on roadsides nationwide. According to register data, by 1 January 2022, a total of 335,900 square metres of rugosa rose had been planted at 1,130 sites on the Finnish road network. Of this total, about 178,800 square metres were located on single carriageways and 151,100 square metres on dual carriageways. The operating model for inventing alien species on the rail network is under preparation and the inventory work will continue in summer 2022.

    The work to eradicate giant hogweed has continued for about ten years as growth locations have been identified. Reports on other invasive alien species have only been received from a small number of areas in Finland.

  • In addition to carrying out inventories, we have also examined ways to combat rugosa rose and their suitability for road environments. We have also examined the cost of combating the plant. In the latest version of the environmental guidelines for railway maintenance, consideration is given to the combating of alien species, and the document also contains instructions on collecting details of their occurrence and on combating them.

    We have issued instructions under which alien species surveys, impact assessments and proposals for measures to combat alien species should be included in infrastructure project plans.

    In 2021, measures to combat alien species as part of road improvement projects were carried out in an area covering about 10,000 square metres. The largest sites were on road 101 (Ring Road 1), main road 15 in Kotka and main road 25 in Raseborg. In 2021, measures to combat alien species in railway areas were carried out in an area covering about 550 square metres. Systematic measures have been taken in recent years to eradicate rugosa rose in canal environments.

  • We have made alien species a key theme in the updating of our guidelines for road landscaping, which is currently underway. The objectives for combating invasive alien species and information on the methods to combat them that are suited for road environments will be included in the guidelines. The updated guidelines will be published in summer 2022. We are constantly working to combat rugosa rose as part of transport infrastructure projects to the extent possible. The efforts to eradicate giant hogweed will continue as part of road and railway maintenance.

  • Our report on prioritising the combating of rugosa rose on the road network will be published in May 2022. The actions set out in the report are based on national guidelines and will provide the basis for the order of priority of the measures to be taken. Highest priority will be given to marine coastal areas and archipelagos and sites close to Natura and other protected areas.

    We will also examine the spread of rugosa rose in railway areas and prepare further action. Eradication of the remaining occurrences of rugosa rose in canal environments will continue in summer 2022. We will continue the work to eradicate rugosa rose as part of transport infrastructure projects.

  • Under the EU legislation and the legislation in effect in Finland, the costs of the measures in relation to the benefits achieved must be taken into account in the combating of invasive alien species. It is impossible to totally eradicate rugosa rose in a cost-effective manner in the near future.

    The key aim in the combating of widespread alien species, such as garden lupine and rugosa rose, is to prevent them from spreading any further. Priority in the eradication is on sites of significant natural value and areas close to them. Eradication of rugosa rose in transport infrastructure areas will take years, if not decades.

  • Eradication of rugosa rose involves a number of problems. Until now, the lack of reception points for alien species waste in different parts of the country has been the biggest bottleneck. In transport infrastructure areas, rugosa rose must often be eradicated by removing both the bushes and their substrate, which will result in a large amount of waste. Municipalities only have a limited number of reception points and not all of them are allowed to receive alien species waste.

    As there are not enough reception points, it is difficult to estimate the costs of eradication and related transport. If the waste is disposed of improperly, the problem of alien species could become even worse. The Waste Act also prohibits the burial of plant waste.

    The costs of combating the species are high, as rugosa rose grows extensively along roads and railway lines. The costs result from the planning of the eradication measures, the eradication itself, transport of waste, waste charges, monitoring and post-treatment. The separation of the plant waste and topsoil would not be a solution as it would be both expensive and difficult to carry out in transport infrastructure environments. This is why, until now, measures to combat the species have mainly been taken in connection with transport infrastructure projects.

    Changes in road environments and urban landscape are also a factor: when planted areas are destroyed, they must usually be replaced with grass so that the growth of shoots can monitored after eradication. This will change the road landscape, making the environments less pleasant.

    It should also be noted that the rugosa roses planted in such places as railway stations and their car parks are not necessarily managed by the Finnish Transport Infrastructure Agency. They may be owned by the municipality or even by private persons.

  • The Finnish Transport Infrastructure Agency has estimated that eradicating rugosa rose on the road network would cost about EUR 5-7.5 million, and when the waste costs (reception charges) are included, the cost would total about EUR 50 million.

  • Rugosa rose bushes must be cut down every few years so that they can maintain their vitality. In road environments, rose hips (rose fruits) containing the seeds may be carried to new growth locations by the equipment used to cut down the plants. Rugosa rose seeds are probably carried to new sites (such as the archipelago) by migratory birds and (along waterways) by flowing water.