In Sweden, there are about 2,000 alien species of which 388 are invasive alien species. Invasive alien species are species that compete and create problems for the native species we have in our nature. One of the major drivers of the introduction of alien species is transport. Transport between different geographical areas increases from year to year, making it easier for new alien species to enter the country. The purpose of this work is to investigate the distribution of alien species along roads of different sizes with different amount of traffic, to be able to get an overview of how the number of cars passing a road affects the spread of alien species and whether it differs among roads. Roads of different sizes were inventoried, in the municipalities of Lekeberg and Laxå, Sweden. Two of the roads were highways, 3 middle sized roads and 3 small sized roads. All species in the sample sites were inventoried, including native species. One-way Anova was used to check if there were any significant differences. The result shows that where most alien species were found, least native species could also be found. Other studies have found linkages between paved roads and invasive species, where it was found that paved roads had more alien species than gravel roads. The result of this study showed that most foreign species could be found along the middle roads and least along the small roads. This could be due to the smaller roads having less traffic intensity, which means that there is less chance of alien species entering these roads by cars. The fact that most species were found on the intermediately sized roads compared to the highways may be due to the higher speed and a higher traffic flow.

Invasive species are an increasing problem worldwide, threatening indigenous communities and species. In a world where people travel and trade a lot in a global market, many organisms are transported to new parts of the world where they have never existed before. Most do not survive in the new environment but die, but some thrive and thrive. When such species are established and multiply in places outside their natural range, it can be followed by negative consequences for species that have existed there for a long time - so-called indigenous species. Then the new species are often called alien invasive species. An example of this is the beautiful and colourful plant flower lupin (Lupinus polyphyllus)that people on their travels brought with them from North America, among other things, Europe. Global warming and increased trade between countries is the main reason why foreign species are introduced to new ecosystems while climate change means that habitats can change to become more suitable for an invasive alien species. The invasive species currently causes major economic losses worldwide. Lupins, park slides, and giant sheds are examples of invasive plants that have been introduced in European gardens because they are beautiful and easy to care for. They are also invasive, spread aggressively and are detrimental to our nature because they penetrate our native species. To stop these invasive plants and from damaging Europe's nature, the EU countries have decided to take action against certain species. On January 1, 2015, the EU adopted a regulation on invasive alien species and how to combat it within the Union. On February 5, 2016, the Swedish Environmental Protection Agency submitted the Authority's proposal to the Swedish Government on new rules and measures on how to stop invasive harmful species. Already today, great resources are being devoted to combating invading plants such in our nature reserves. However, an early preventive or direct targeted intervention is much more cost effective than a continuous control of unwanted, invasive species with well-established populations. In order to succeed in this, we need an increased awareness of the problem of alien, invasive species among the public and decision makers, but also a sharp global analysis. Only with knowledge and continuous monitoring can we put in early action against future, aggressive invaders.