Continuous grazing systems (CGS) are still widely used for managing cattle herds in the south-western Alps. Recently, Pastoral Plans have been used as a policy tool to improve grazing management. Rotational grazing systems (RGS) with large paddocks (i.e. ~100 ha on average) and stocking rate adjustments based on recommended levels calculated from vegetation surveys have been implemented through Pastoral Plans to improve the uniformity of grazing. A case study was conducted to compare grazing distribution patterns of beef cows during the summer under CGS and RGS on sub-alpine and alpine pastures within Val Troncea Natural Park in the south-western Alps of Italy. Cows were tracked with global positioning system collars at 15-min intervals under both CGS and RGS. Cattle distribution patterns were aggregated in both grazing systems, but in the RGS concentration of grazing was less clustered and the selection of vegetation communities was more homogeneous than in CGS. Under CGS, cows were attracted (P < 0.05) to salt placements and areas with high forage pastoral values, and they avoided (P < 0.05) steep slopes. In contrast, cows under RGS were not influenced by (P > 0.05) high pastoral value, and they avoided areas farther from water (P < 0.05). Similar to CGS, cows under RGS were attracted (P < 0.05) to salt and avoided (P < 0.05) steep slopes. In the RGS, cows used steeper slopes and areas farther from salt and water in the second half of the grazing period within a paddock compared with the first half, which likely explains the improvement in uniformity of grazing with RGS. Our findings indicate that Pastoral Plans that combine appropriate stocking levels and RGS are valid policy and management tools that have the potential to improve grazing distribution on rough sub-alpine and alpine pastures in the south-western Alps.
In recent decades, pastoral abandonment has produced profound ecological changes in the Alps. In particular, the reduction in grazing has led to extensive shrub encroachment of semi-natural grasslands, which may represent a threat to open habitat biodiversity. To reverse shrub encroachment, we assessed short-term effects of two different pastoral practices on vegetation and dung beetles (Coleoptera, Scarabaeoidea). Strategic placement of mineral mix supplements (MMS) and arrangement of temporary night camp areas (TNCA) for cattle were carried out during summer 2011 in the Val Troncea Natural Park, north-western Italian Alps. In 2012, one year after treatment, a reduction in shrub cover and an increase in bare ground cover around MMS sites was detected. A more intense effect was detected within TNCA through increases in forage pastoral value, and in the cover and height of the herbaceous layer. Immediately after treatment, changes in dung beetle diversity (total abundance, species richness, Shannon diversity, taxonomic and functional diversity) showed a limited disturbance effect caused by high cattle density. In contrast, dung beetle diversity significantly increased one year later both at MMS and TNCA sites, with a stronger effect within TNCA. Multivariate Regression Trees and associated Indicator Value analyses showed that some ecologically relevant dung beetle species preferred areas deprived of shrub vegetation. Our main conclusions are: i) TNCA are more effective than MMS in terms of changes to vegetation and dung beetles, ii) dung beetles respond more quickly than vegetation to pastoral practices, and iii) the main driver of the rapid response by dung beetles is the removal of shrubs. The resulting increase in dung beetle abundance and diversity, which are largely responsible for grassland ecosystem functioning, may have a positive effect on meso-eutrophic grassland restoration. Shrub encroachment in the Alps may therefore be reversed, and restoration of grassland enhanced, by using appropriate pastoral practices.
1 August 2019 in Agriculture, Ecosystems & Environment