The Brignant plots, managed by Aberystwyth University, were established in 1994 to test the effectiveness of different extensification managements when applied to upland-fringe pasture.
The plots were established on Lolium perenne-dominant pasture that had been ploughed and reseeded in 1973, and which had received regular inputs of fertilizer and lime.
Plots are arranged in a randomized block design with three blocks and a total of seven grassland management regimes imposed on individual plots.
Treatments are: sheep grazing, hay cut only, and hay cut with aftermath grazing; each with and without the addition of lime. Plots are 0.15 ha (grazed) or 0.08 ha (hay cut only) in size. Control plots continuing the previous site management (i.e. limed, fertilised and continually grazed by sheep) are also included within each block.
Early results indicated promising initial prospects for restoring species-rich grassland communities through natural species colonisation (MAFF projects BD0317; BD1424). They also indicated that different extensive managements could vary the rate and direction of early successional changes.
Continuation of the treatments (MAFF project BD1452) demonstrated that cessation of fertilizer use and the imposition of extensive management practices allowed moderately species-rich grassland communities to develop within a 10-year timescale by natural regeneration. The most effective extensive management for grassland biodiversity restoration was hay cutting with aftermath grazing.
The treatments have now been imposed for 20 years. Recent (2012) surveys found that management regime continues to be a key driver in terms of diversity of vascular plant species. Substantial treatment effects on arthropod foliage fauna have also been recorded (2013).