Individual study: Grassland conservation headlands: a new approach to enhancing biodiversity on grazing land
Haysom K.A., McCracken D.I., Roberts D.J. & Sotherton N.W. (2000) Grassland conservation headlands: a new approach to enhancing biodiversity on grazing land. Grazing Management: the Principles and Practice of Grazing, for Profit and Environmental Gain, within Temperate Grassland Systems: Proceedings of the British Grassland Society Conference, 29 February-2 March, 2000, Harrogate, UK, 159-160.
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Create open patches or strips in permanent grassland
A randomized, replicated, controlled trial in 1997 and 1998 in Scotland, (Haysom et al. 2000) found that conservation management of permanent pasture field headlands (protection from summer grazing and clearing strips in the sward using herbicides) substantially increased the number of chick-food insects. The study measured the effect of different combinations of grazing and herbicide strip treatments on the numbers of true bugs (Heteroptera), sawfly larvae (Symphyta) and caterpillars (Lepidoptera). Treatments began in 1997, and insects were sampled in June and July in 1997 and 1998. By 1998, headlands protected from summer grazing had 19-32 times more chick-food insects (609 true bugs, 75 sawflies and 18 caterpillars, on average per 10 samples) than grazed headlands (19 true bugs, 2 sawflies and 1 caterpillar). Clearing strips in the sward (to allow birds easier access to insects) initially reduced the numbers of caterpillars and sawflies, but they recovered by 1998, when vegetation in bare areas had regrown.
Reduce grazing intensity on grassland (including seasonal removal of livestock)
A randomized, replicated, controlled trial in 1997-1998 on permanent pasture at three sites in Dumfries and Galloway, Scotland, UK (Haysom et al. 2000) found that fencing of field headlands to prevent grazing during the summer, substantially increased the abundance of three key chick-food insect groups. After one year, headlands protected from summer grazing had 19-32 times more chick-food insects (609 true bugs (Hemiptera), 75 sawfly larvae (Symphyta) and 18 caterpillars (Lepidoptera), on average per 10 samples) than grazed headlands (19 true bugs, 2 sawfly larvae and 1 caterpillar). Treatments were carried out from spring 1997 in adjacent plots (10 x 50 m long) on the boundaries of seven pasture fields: unfenced unsprayed, unfenced sprayed, fenced (May-September) unsprayed, and fenced (May-September) sprayed. In sprayed plots, herbicide was applied in April 1997 to clear strips to trial a method for increasing foraging access for birds. Unfenced plots were grazed by cattle and sheep during summer, and all plots were intermittently grazed by sheep during winter. Insects were sweep net sampled in June and July in 1997 and 1998.