BARBARA TOKARSKA-GUZIK

University of Silesia,
Faculty of Biology and Environmental Protection, Department of Plant Systematics;
Jagiellońska 28, 40-032 Katowice
e-mail: barabara.tokarska-guzik@us.edu.pl

Description popularizing the research project

You cannot be more wrong when you think that plants do not move, that they stay where they have been planted or where they were able to set their roots. They migrate and it is a common trait that share both tiny plants growing between cobblestones and huge trees in our parks. Like all living creatures they care so that their species spread in the largest possible territory. They set off on their pilgrimages on their own or with a little help of other mobile creatures.
Nobody but Macbeth has ever seen walking trees or how the wood advances into fields. Strawberry growers in their gardens see twisting shoots with tiny plants at the ends which start new shoots. If you let them they would cover the whole available area. But there are other options as well. You may project seeds as if with a catapult. The farther, the better. Or let the seeds be carried by winds. This is why the whole meadow blooms with yellow dandelions and there are so many birches there. The most refined way is to be carried by somebody other by grabbing somebody's tail, fur or, as it is in case of fruit eating birds in their stomachs. Then all you have to do is to get off at any station. In this way you can cover the distance of many kilometers. Yet the smartest and the fastest it is when it is the man who transports the seedlings trying to make gardens more attractive. What obstacle is a fence there? None whatsoever. The way to natural habitats lays wide open. Very often the native species struggling with caterpillars, fungi, excess or shortage of water and light, have to withdraw and make room for the self-confident intruders. Most of the wanderers found place for themselves in cities. Is it good or not? Well, you never have enough of green in there. It is striking how good the alien species feel in the conditions. Does it mean the conditions in Poland and China do not differ so much? It sounds very worrying. In fact the newcomers have very wide tolerance margin, otherwise they would die on the way. Moreover the niche for expansion is very specific as they are old walls and cracks between cobbles which are almost the same all over the world. Plants are on the march. No fireworks, banners or phone calls announce their coming. Should we be pleased they feel at home here?

Abstract

The aim of the project was to analyze selected aspects of habitat preferences of 75 kenophytes (= neophytes, alien plant species which arrived in Poland after 1500 A.D., so called “newcomers", permanently established in different types of habitats) in order to understand their ability to invade. Because urban flora generally includes a high proportion of alien species they were considered to be sufficient samples for the analysis. Researches have been undertaken in urban and suburban areas of 21 mediumsize towns selected throughout the country along a southnorth gradient. Altogether about 41 types of habitats were distinguished starting from the less disturbed (natural, semi-natural) situations and progressing through to the more anthropogenic ones. In each type of habitat the presence and abundance of particular species was recorded. The majority of kenophytes show an ability to adapt to a relatively wide range of habitats with a prowling tendency to disturbed ones. Habitat types such as railways and urban wastelands are the ones most frequently invaded by alien plant species. Another group of habitats quite frequently penetrated by kenophytes are farmland habitats, particularly arable land, abandoned fields as well as roadsides. Natural and semi-natural habitats are also invaded occasionally. Of these, watersides are the habitats with the most frequent presence of kenophytes. Species adapt to a wide range spectrum of habitats are for example: Conyza canadensis (recorded in 32 different types including natural and seminatural) and Acer negundo (recorded in 31). Only a few species can be named as faithful to a particular type of habitat: Corydalis lutea and Cymbalaria muralis - both coming from Central and Southern Europe, grow only in crevices in remnants of old walls; Eragrostis minor was recorded on railways, store yards and in the centers of towns between flagstones. Attention should be paid to that group of kenophytes with relatively great competitive potential which are capable to penetrate into natural habitats: aquatic, riparian, grassland, meadow and woodland.