The potential of cutting regimes to control problem weeds and enhance species diversity in an arable field margin buffer strip

Tarmi S, Helenius J & Hyvonen 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.