Abstract ID: 3.14065 | Accepted as Talk | Talk/Oral | TBA | TBA

Alpine pastures are fundamental resources for mountain farming systems, providing high-quality forage for livestock. Grazing activities – including defoliation, trampling, and dung deposition – significantly influence vegetation composition by depleting biomass and modifying nutrient availability. Such impacts on grassland ecosystems can considerably vary, depending on the diverse environmental conditions and stocking density. Understanding livestock distribution is therefore essential for developing effective management strategies to balance vegetation availability and livestock needs. However, obtaining precise data on livestock distribution remains challenging. Indeed, direct method, such as GPS collars, yield detailed insights into grazing patterns, even if their high cost and labor-intensive implementation prevent their widespread adoption. Indirect method, i.e. spatial modelling through distribution probability maps, may not account for all relevant variables. A study conducted in a summer pasture within Gran Paradiso National Park (NW Italy, 1800-2400 m a.s.l.) investigated an 83-hectare area exploited by 100 Pustertaler-Barà cattle (87 LU). To assess livestock distribution over a 75-day grazing period, GPS collars were deployed on 10 selected animals. At the conclusion of the season, field assessments recorded grazing evidences – defoliation, trampling, and dung deposition – on 715 regular ground control points, employing a five-grade scale (1 = absence, 5 = extreme). The study aimed to determine which of these indicators most accurately represented site-use intensity, based on GPS fixes recorded within 5-meter buffers around each control point. The findings demonstrated that the three grazing indicators effectively captured variations in pasture frequentation. Among them, defoliation proved to be the most reliable, pointing out clear distinctions in grazing intensity except at the highest level. Dung deposition also showed a suitable performance, while trampling proved to be less reliable in differentiating between moderate, high, or extreme intensities. These results highlight the value of easily observable grazing indicators as practical tools for assessing site-use intensity by grazing livestock in extensive alpine pastures. This approach presents an opportunity of supporting effective pasture management strategies, mitigating vegetation degradation and promoting the sustainable management of mountain farming systems.