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Tarmi S, Helenius J & Hyvönen T (2011). The potential of cutting regimes to control problem weeds and enhance species diversity in an arable field margin buffer strip. Weed Research51, 641–649. Summary Buffer zones in arable land could promote biodiversity of agricultural areas. These are most often established with sown seed mixtures of grasses and herb species. We studied the impact of cutting management and the role of the seedbank on plant species diversity of a sown buffer strip. Two main hypotheses H1 were tested in this study: (i) sward cutting and removal have positive effects on plant species diversity in a buffer zone adjacent to a cultivated field and (ii) the buffer zone soil seedbank and adjacent grassland act as a species source for the managed buffer zone. After 5 years of management, the number of species was significantly higher and the litter coverage significantly lower in plots mown yearly with cuttings removed than in mown plots with the cuttings left or an uncut control. The abundance of Elymus repens was not affected by the cutting management. To reduce E. repens probably needs cutting more frequently than once per year. Cutting management did not reduce easily‐soluble phosphorus in soils. For species colonisation, adjacent grassland played a more important role than the soil seedbank. We conclude that, in this study, the reduced litter cover, together with adjacent sources of species, resulted in the gradual increase in species diversity in the species‐poor buffer habitat. This study took place in a single location and similar studies in additional locations would be helpful in assessing the generality of our results. On the evidence of this study, the contract periods of agri‐environmental schemes should be longer than 5 years to ensure cutting does result in positive benefits for the management of biodiversity.

To determine the importance of field boundary habitats for farmland biodiversity, we surveyed a total of 193 boundaries from four climatically and agriculturally dissimilar regions in Finland. We measured the current plant species richness and composition of the boundaries, and, based on the differences in vegetation characteristics, we describe six boundary types.The observed plant species were mainly indicators of fresh to wet soils and moderate to rich mineral nitrogen content. The most frequent species were tall, perennial monocots and dicots indicating the high productivity of the vegetation. Moreover, herbicide-tolerant species were common. No species rare for Finland were found. In animal husbandry regions, the most frequent species were sown grassland species and typical grassland weeds. In cereal production regions, fast-spreading root weeds tolerant of herbicides were the most frequent. Mean species richness was highest in the cluster Calamagrostis-Phalaris (24 species (s) / boundary (b)), which we considered as representative of moist sites with some disturbance by agricultural practices. Most species-poor were the clusters ElymusAnthriscus (14 s/b) and Elymus-Cirsium (16 s/b), both found predominantly in cereal production regions in southern Finland.Our results suggest that the biodiversity value of boundaries is lowest in the most intensive cereal production areas and highest in areas of mixed farming.