The plant species in the
farmland come from different vegetation types and they are generally
adapted to regular distubance of the ground. Many of the species are
not naturally occuring in Denmark but has come to the country through
agriculture mainly from Central and Eastern Europe. Most of the weed species can grow and spread their seeds before the soil is ploughed at the end of the season. Many weeds produce a large number of seeds, which can stay dormant in the ground for several years and germinate under the right conditions mostly when exposeed to light. Other species produce long stolons etc. which quickly can produce new plants. The species in the crop fields are distributed througout Denmark according to climate and soil properties. But he managemanet of the ground can also have a great influence on the occurence of single species. The right picture shows that Dandelions - Taraxacum - is a very common species in grass pastures. Dandelions can spread a long distance due to their light seeds. In the background of the picture is a field of yellow flowering oilseed rape - Brassica napus - a commun sight in spring in Denmark.
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