Importance of edaphic, spatial and management factors for plant communities of field boundaries

Plant communities of 57 field boundaries, in four regions of Finland, were sampled for this study focusing on factors affecting species diversity and community composition. All the boundaries were buffer strips established following the guidance of an Agri-Environmental Support Scheme. Data on edaphic factors, boundary management practices and spatial coordinates were used as explanatory variables in the data analyses using variation partitioning by Redundancy Analysis and univariate statistics. The variation of the plant species composition and diversity was found to be strongly spatially structured. On the variation of species composition, spatial variables alone explained 35.0% and jointly with environmental factors 32.4% of the variation in species composition. Moreover, mowing, soil pH and P content and boundary width were shown to be important factors determining species composition. The species diversity was the lowest where the land use for agricultural production was most intensive and classification of species traits indicated high soil nitrogen levels. On the basis of this study, biodiversity in boundaries could be enhanced by appropriate management techniques and greater boundary width. Regional differences in agricultural land use should also be taken into account when planning practices for improving biodiversity.