Assessment of the long-term impact of deer on understory vegetation in mixed temperate forests

Questions What is the long-term impact of deer browsing on the diversity of the herbaceous layer and tree species regeneration? Which parameters of the tree species regeneration and herbaceous layer best indicate browsing impact? Location Dinaric Mountains, Slovenia. Methods We studied the long-term impact of red deer on mixed temperate forests by comparing the tree species regeneration and herbaceous layer vegetation under two treatments: deer present, no deer. We analysed the tree regeneration older than one year up to a diameter at breast height of 10 cm (categorized into five height classes) and the cover abundance of plant species in the herbaceous layer (<50 cm). Results There were no significant differences in the number of tree species regeneration between the treatments. Browsing impact on the most abundant tree species - European beech, silver fir and sycamore-varied, indicating differences in palatability. Under the presence of deer, the number of silver fir regeneration was significantly lower in all height classes, and European beech regeneration shorter than 50 cm was more abundant, while for sycamore shorter seedlings (