- USE OF SHEEP GRAZING IN THE RESTORATION OF SEMI-NATURAL MEADOWS 45 Abstract. The biodiversity of species-rich semi-natural mead- ows is declining across Europe due to ceased management. In this study we aimed to find out how successfully the local species richness of an overgrown semi-natural mesic meadow could be restored by sheep grazing after a long period of abandonment. The cover of vascular plant species in grazed plots and ungrazed exclosures was studied for five years and the responses of different functional plant groups were fol- lowed (herbs vs grasses, tall vs short species, species differing in flowering time, species representing different Grime’s CSR strategies and species indicative of rich vs poor soil). Grazing increased species number by nearly 30%. On grazed plots the litter cover practically disappeared, favouring small herbs such as Rhinanthus minor, Ranunculus acris, Trifolium pratense and the grass Agrostis capillaris. Grazing decreased the cover of the late flowering tall herb Epilobium angustifolium but had no effect on the abundance of the early flowering tall herbs Anthriscus sylvestris or Geranium sylvaticum. We sug- gest that to succeed in restoration it is useful to determine the responses of different functional plant groups to grazing. Grassland managers need this information to optimize the methods and timing of management used in restoration. Addi- tional management practices, such as mowing, may be needed in mesic meadows to decrease the dominance of tall species. The availability of propagules seemed to restrict further in- crease of species richness in our study area. Keywords: Functional plant group; Litter accumulation; Plant life history group; Poor soil; Rich soil; Species diversity. Nomenclature: Hämet-Ahti et al. (1998). Abbreviations: GRI = Grazing response index; NMDS = Non-metric MultiDimensional Scaling. Introduction Traditional, low intensity management of semi-natu- ral grasslands has enriched the flora and fauna in many European countries. Many species are dependent on these man-made environments: for example 28% of threatened plant and animal species live on semi-natural grasslands in Finland (Anon. 2000). The threat to these species is a rapid decline of semi-natural meadows which has taken place during recent decades in many European countries, including Britain (Gibson et al. 1987), The Netherlands (Berendse et al. 1992), Switzer- land (Stampfli & Zeiter 1999), Sweden (Eriksson et al. 1995) and Finland (Hæggström et al. 1995). In Finland the area of these meadows reached a maximum of 1.6 million ha in the 1880s, but had declined to only 18690 ha in the national inventory in the 1990s (Anon. 2000). Urgent management is needed in order to stop shrub encroachment and to restore the characteristic species composition of these old pastoral areas. When planning restoration practices data on re- sponses of different plant growth forms to grazing are needed. Grazing may enhance species diversity by fa- vouring weakly competitive plant species at the expense of tall competitors. Selective grazing also alters inter- specific competition because the most palatable species are eaten first (Daubenmire 1968). According to Grime (1977) grazing causes a disturbance that favours ruderals, typically annuals (R-strategy). Dry meadows are typi- cally inhabited by stress tolerators (S-strategy, sensu Grime 1977), which are able to withstand water and nutrient deficiency. In contrast, species that benefit from a lack of management are typically tall and broad- leaved species with good light competition ability (C strategy, sensu Grime 1977). They often suppress the growth of smaller growing species. However, tall com- petitors do not tolerate regular cutting and decrease in abundance when grazing is reintroduced (Grime 1977). Grasses are often better adapted to grazing than herbs Use of sheep grazing in the restoration of semi-natural meadows in northern Finland Hellström, Kalle * ; Huhta, Ari-Pekka; Rautio, Pasi; Tuomi, Juha; Oksanen, Jari & Laine, Kari Department of Biology, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland; * Corresponding author; Fax +35885531061; E-mail kalle.hellstrom@oulu.fi Applied Vegetation Science 6: 45-52, 2003 © IAVS; Opulus Press Uppsala.