Semi-natural grasslands: landscape, history and plant species diversity

This thesis explores the impact of past and present landscape and habitat structure on present levels of vascular plant species diversity within fragmented semi-natural grasslands. Within the Jordtorp-area, a mosaic agricultural landscape on the island of Öland (Sweden), historical land-use changes and the development of semi-natural grasslands was characterized, over a time-period of almost 300 years, using historical maps, aerial photographs and a high-resolution imagery. The study also examines the relative importance of management conditions and habitat history (in terms of continuity, previous land-use), on present-day vascular plant species diversity within the semi-natural grasslands. Present-day grasslands represent 18% of the grassland area found at the beginning of the 18th century. The most dramatic loss of grassland habitat took place between late 19th century and the beginning of the 20th century, resulting in a progressive grassland fragmentation during the 20th century. Results from the Jordtorp-area showed that present levels of small-scale (