The abandoned Danthonia alpina Grasslands on Monte San Giorgio Evidence of floristic changes and suggested management practices

The grasslands on Monte San Giorgio, Ticino, are recognized as a plant community unique to Switzerland (alliance: Mesobromion) containing many isolated, rare, and endangered taxa. The vegetation pattern reflects a gradient of soil depth probably caused by different dolomitic and tuffitic strata of the underlying bedrock. Successional changes after abandonment and uncontrolled fires have favoured Molinia arundinacea on relatively deep soils, resulting in a general decrease of species richness. In field experiments M. arundinacea was reduced in abundance by mowing in early August but favoured by removing litter in early spring. Suggested management practices are mowing, at various locally defined mowing regimes, or, limited to a few areas, grazing by donkeys in late summer, both combined with cutting of shrubs and trees. Controlled burning may also be recommended, but fires have to be set at very small scale, and at intervals of several years, and effects must be well studied over a long term. Removing litter by rake in spring and grazing by sheep or goats are not recommended.