Grazing is widely used to manage grasslands, but its effects on plant diversity and community composition are context-dependent. In the Canary Islands, pastures are limited and fragmented but represent some of the most species-rich plant communities. This study evaluates the effects of grazing abandonment and grazing intensity on plant diversity and composition in the mountain pastures of Gran Canaria under wildfire prevention management. Vegetation was surveyed in 11 paired grazed and ungrazed plots across an environmental gradient over two years. Grazing intensity was quantified using livestock GNSS (Global Navigation Satellite System) tracking, distinguishing low- and high-intensity regimes. A total of 112 plant species were recorded, mostly typical of pasture communities. Species richness remained stable across treatments, grazing intensities, and years (2023–2024), indicating strong short-term resistance. However, species composition varied along the grazing intensity gradient: high-intensity grazing produced more homogeneous communities dominated by grazing-tolerant species, while low-intensity grazing maintained greater variability. Grazing abandonment showed no clear compositional shifts, suggesting delayed responses. Environmental factors such as soil, moisture, temperature, and coastal influence also structured species distributions. Overall, grazing intensity is the main driver of plant community structure, highlighting its importance for biodiversity conservation, wildfire risk reduction, and maintaining traditional pastoral practices.
Arevalo et al. (2026) studied this question.