Förändringar i vegetationens sammansättning efter en våtmarksrestaurering
Changes in the vegetation composition after a wetlandrestoration
The loss of such great wetlands, which has arose in Sweden the last decades, has created a situation that threats both the function and the biological diversity within the wetlands. Many ecological niches can be found in the wetlands and it is one of the habitats where most different species exist. In the 17th Century people started to ditch damp environments, such as bogs, to create a productive cultivated ground. Further ditches were made when the forestry gave large economical profits. The wetlands were impoverished from both groundwater and nourishment, and this led to a great loss of species.In a corporation with WWF and Skogsstyrelsen in Arvika, the University of Karlstad has participated in the Laskerudproject, a hydrological restoration-project in a forest landscape. The purpose of the project was to increase the groundwater level and to recreate the functions of the wetlands. The project has partly analysed the change in the vegetations composition during six years. The restoration took place in the year 2004 and the inventory of the wetland?s flora has been carried on between the years 2002 and 2007. The same 40 test-squares in Södra ängsmyren, which have been chosen at random, have been analysed every year in august; also 40 randomly chosen test-squares in Lenungen where looked at. The latter were used as a control area.All occurring species have been analysed statistically with the parametric z- and t-test and the non-parametric Wilcoxon-test. This was made to analysed if the hypotheses that the number of alter species are more in Södra ängsmyren than in Lenungen. The hypothesis if the hydrophilic species have increased and the hydrophobic species have decreased in Södra ängsmyren was also analysed the same tests mentioned above.The results of the analysed material showed a significant increase in two of the species in both Södra ängsmyren and Lenungen. The remainder species in Södra ängsmyren could show interesting trends, even though they were not significant. Some species in the wetlands have got a wider area of distribution, this has been visually observed. In comparison with similar studies this study shows the conclusion that more time is needed to prove the changes statistically. As a suggestion, three to five years of further data of the wetlands flora is needed to prove the changes statistically.