Vegetation height of patch more important for phytodiversity than that of paddock

The development of phytodiversity was analysed on a paddock (1 ha) as well as on a patch scale (1 m2) over nine years on paddocks managed for compressed sward heights (CSH) of 6 (moderate stocking, MC), 12 (lenient stocking, LC) or 18 cm (very lenient stocking, VLC) on moderately species-rich mesotrophic grassland. Neither grazing treatments nor nutrient availability caused differences in diversity measures in this study. The local quadrat vegetation height had a significant influence on average species number and Shannon diversity, independent of the grazing treatment. Patches with short vegetation allowed seed germination and reduced dominant species, making a diversification of the vegetation measurable at an earlier stage than on the paddock scale.

► Extensive grazing should increase phytodiversity.
► Cattle grazing to three sward heights in moderately species-rich long-term pasture.
► Grazing intensity and soil nutrients did not affect phytodiversity significantly.
► Patches with short vegetation had more species and higher Shannon diversity.