Analyses of pollen and charcoal in peat cores, together with age-structure data of Pinus sylvestris from a Ledum-Pinus-Mire in the Tyresta National Park (south-east Sweden) show the regional vegetation succession and fire history over the last 9000 years. Five major stages of Mire development are identified: 1. Lake (c 7000-6400 cal BC); 2. Wet fen (c 6400-6000 cal BC); 3. Deciduous fen (c 6000 cal BC to c cal AD 700); 4.

Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Trädgårdens hantverk och design 21 hp.

In Sweden there are about 4 million hectares of bare peat (Mire). This land has great potential to be transformed into productive forest land, provided drainage is carried out and, in some cases, even fertilization with ashes. Drainage of Mires is necessary because the high groundwater table prevents trees from growing due to reduced oxygen availability. Some of the key nutrients that trees need to grow appear in too small quantities in Mires, especially potassium (K) and phosphorus (P). Ash from the combustion of biomass contains these elements and is therefore suitable as a fertilizer.

Metan är en stark växthusgas som är viktig att ta med i beräkningarna när det gäller klimatförändringar. Feedback från myrmarker vid en ökad temperatur i samband med klimatförändringar har diskuterats, bland annat eftersom myrmarker är en källa för metan till atmosfären. Det finns många faktorer som påverkar metanemission, och en av dom är vegetation. Olika sorts vegetation tros bidra olika mycket till avgivningen av metan. Syftet med denna studie var att undersöka hur stor betydelse det har att ta med olika växtsamhällens sammansättning i beräkningarna för att uppnå korrekta uppskattningar av metanemission från myrmark på ekosystemnivå.

By using pollen analysis, 14C-dating and historical sources, I studied the history of vegetation and land use at an abandoned forest settlement near the Lade summer farms in the parish of Mora, Dalama. The aim of this paper is to investigate the agricultural establishment and development, the effects of this on forest vegetation, and the origin and development of summer farming. The analysis of pollen in a peat core revealed that a settlement was established at Lade around 1000 AD. Cereal cultivation, hay-making on the Mire and extensive forest grazing were intro-duced as a complete agricultural system. Pollen analysis and the presence of ancient fields suggests that cultivation took place on permanent fields. Barley was the main crop, but rye and hops/hemp were also grown at the settlement.

The forest and Mire landscape surrounding the north Swedish villages have been of fundamental importance through time for the farmers. In the Scandinavian summer farm system the forest and Mire pasture was used to its full potential. The system consisted of smaller summer farms some kilometres from the main farm in the village, and were the livestock grazed in the forest around the summer farm. The livestock affect their environment, and grazed forests generally contain a higher biodiversity than an ungrazed forest. The overall aim of this thesis is to understand the impact of livestock grazing on a northern forest ecosystem over a long time period.