Neutral Impact of Cattle Grazing in Pyrenean Oak Forests Integrity

The combination of logging, burning, and livestock farming has been the main driver of European landscape sustainability for thousands of years. Whether or not livestock could keep these habitats on their own is under debate when extensive livestock grazing is kept understory in forests of high environmental value that, in turn, are affected by global warming. In this work, the impact of beef cattle on the diversity, shrub cover, and primary production of the Atlantic Pyrenean oak (Quercus pyrenaica Willd.) in northern Spain has been evaluated. The research studied their feeding habits using the faecal cuticle micro histological analysis in dung samples. Then, the effects of cattle grazing on the cover and alpha diversity of woody plants were evaluated. Finally, oaks’ primary production and phenology in grazed and control areas were compared. The results show that cattle feed on woody (an average of 30% of non-leguminous woody) and annual plant species (more than 20% of forbs) but do not affect plant cover or alpha diversity of vegetation. However, oak phenology differed between grazed and ungrazed treatments, probably due to the spatial variability of grazed forests. It can be concluded that understory grazing in Pyrenean oak forests could be considered a sustainable silvopastoral activity with a neutral impact on forest integrity.