Long-term impacts of extensive grazing and abandonment on the species composition, richness, diversity and productivity of agricultural grassland

Reduce grazing intensity on grassland (including seasonal removal of livestock)

A long-term randomized, replicated, controlled trial from 1990 to 2005 at two upland grassland sites in North Lanarkshire and Scottish Borders, Scotland, UK (Marriott et al. 2009) found that a reduction in the level of grazing on intensively grazed and fertilized grassland led to an increase in the number and diversity of plant species. However, these changes were very slow and, in some cases, still ongoing after 16 years, suggesting that recovery from intensive management can take many years. Four grazing regimes were applied from spring 1990: conventional management (grazed to maintain grass at 4 cm, with fertilizer), two reduced grazing treatments (grazed to maintain grass at 4 cm or 8 cm, with no fertilizer) and an ungrazed control (with no fertilizer). Each treatment was replicated twice at each site in roughly 0.5 ha plots. Plants were sampled annually in June-July from 1990 to 2005 using an inclined point quadrat (18 quadrats/plot), except in 1991, 1993, 1995, 2002 and 2004.