Effects of agri-environment schemes on scrub clearance, livestock grazing and plant diversity in a low-intensity farming system on Oland, Sweden

Changes in land use during the past century in semi-natural landscape caused bush and tree encroachment in many pastures and hay meadows-here exemplified by alvars (limestone grasslands) in the Baltic island of Oland (Sweden). Positive changes have been recorded after introduction of agri-environment schemes and economic support. Increased figures are shown for areas being grazed, for the number of sheep and young cattle as well as for economic support within Morbylanga (Oland) municipality and in Kalmar county, but not that clear for Sweden in total.

Reintroduced cattle grazing in a 15-year ungrazed alvar area increased the number of vascular plant species and reduced canopy height, litter thickness and vascular plant cover. The abundance of 12 species out of 72 increased significantly while that of two species decreased. The presence of small. anthills created by Lasius niger compensated for and even increased the number of vascular species in plots ungrazed for 32 years. After clearings in a dense Juniperus communis scrub at least 3-4 years are needed for regeneration of the field- and bottom layers. For the tong-term clearings should be repeated or cattle grazing re-established. (c) 2005 Published by Elsevier GmbH.