Diss. (sammanfattning) Umeå : Umeå universitet, 2008. / Härtill 4 uppsatser.

Peatlands are important and common wetland ecosystems where the wet conditions result in formation and accumulation of peat, i.e., not fully decomposed organic matter. Many peatlands have been negatively affected by drainage (i.e., ditches) and restoration is conducted, although the effects on vegetation are not fully understood. This study aimed to investigate the differences in vegetation composition between natural and restored parts of peatlands and the effect of local conditions on vegetation composition. Data was collected on vegetation composition and local environmental conditions (pH, electrical conductivity and water table depth) of natural and restored parts of seven peatlands across Sweden. Statistically significant differences in the species composition between natural and restored parts were detected and natural parts were dominated by Sphagnum species while restored parts were characterised by shrubs and sedges. The environmental variables had a similar impact on the vegetation composition of both northern and southern sites and were in line with the microhabitat preferences of different species. Although restored parts still have a lower cover of Sphagnum, the vegetation community appears to develop towards compositions similar to those of natural peatlands as most plots are dominated by species found in both natural and restored parts. However, this study is based on vegetation data collected in one year and the results only show the current vegetation community composition and should be interpreted cautiously when evaluating the long-term development of vegetation composition after peatland restoration. As peatlands form during long periods of time, differences in vegetation composition after this relatively short time were expected and in line with previous research. Further studies and long-term follow-up surveys are needed to better understand the vegetation development after peatland restoration.

1928 beslutades att ån Sennan norr om Karlstorp skulle sänkas, rätas ut och delvis kanaliseras för att öka arealen produktiv jordbruksmark. Men åtgärderna orsakade även flera problem både inom och utanför det område som man undersökte innan genomförandet. Dräneringen ledde till att torvmark torrlades vilket orsakar utsläpp av växthusgaser. Vattnets uppehållstid i landskapet kortades och infiltration till grundvattnet minskades. Den biologiska mångfalden minskade genom habitatförlust, alltså färre livsmiljöer, och även genom ökade mängder lösta organiska ämnen i vattnet. Dessa negativa effekter går att motverka genom restaurering. Höjning av grundvattennivån och igenläggning av diken skulle förbättra hydrologin och förbättra grundvattenbildningen. Återvätning av torvlagren hade minskat utsläppen av växthusgaser och våtmarken hade förlängningen istället kunnat fungera som kolsänka. Restaurering av ån och torvmarken kan bromsa habitatförlusten och skapa nya habitat som med tiden kan bli koloniserade och öka den biologiska mångfalden. Eftersom varje lokal har unika förutsättningar är det är svårt att beräkna hur mycket utsläppen skulle minska, värden på hydrologiska faktorer och till exempel eventuell ökad artrikedom. Aktuell forskning visar att restaurering av torvmarker och vattendrag kan leda till förbättrad hydrologi, minskade utsläpp av växthusgaser och ökad biologisk mångfald, även om det i vissa fall kan ta lång tid innan ekosystemet anpassat sig och de positiva effekterna av restaurering blir märkbara. Med tanke på dagens miljöproblem med klimatförändringar, torka, översvämningar och utarmning av den biologiska mångfalden är restaurering av detta område mycket angeläget. / In 1928 it was decided that the stream Sennan north of Karlstorp would be drained and straightened to increase the area of ​​productive agricultural land. But it also caused several problems both inside and outside the area that were being investigated before implementation. The drainage caused peatland to dry, causing greenhouse gas emissions. Water residence time in the landscape was shortened and groundwater infiltration was reduced. Biodiversity decreased through habitat loss and increased amounts of dissolved organic matter in the water. These negative effects can be counteracted by restoration. Raising the groundwater level and ditch blocking improves hydrology and increases groundwater formation. Rewetting of the peat layers reduces greenhouse gas emissions and the wetland can instead function as a carbon sink. Restoration of the river and peatland reduces habitat loss and creates new habitats that will eventually become colonized and increase biodiversity. Because each site has unique conditions, it is difficult to calculate in what amount emissions would decrease, values ​​of hydrological factors and, for example, possible increased species richness. Recent research shows that restoration of peatlands and streams leads to improved hydrology, reduced emissions of greenhouse gases, and increased biodiversity, although in some cases it may take a long time for the ecosystem to adapt and the positive effects of restoration become noticeable. Given today's environmental problems with climate change, drought, floods and loss of biodiversity, restoration of the affected area is very desirable.