Differential effects of cattle, mule deer, and elk herbivory on aspen forest regeneration and recruitment

摘要: Abstract The abundance and composition of ungulate herbivore communities are changing globally, which can impact the resilience function Earth’s ecosystems. Impacts from herbivory compounded in areas where multiple ungulates overlap, is common forest objective this study was to examine differential combined effects (deer, elk, cattle) on aspen recruitment after fires that occurred 2012. Eight sets exclosures, monitored by camera traps, were established across three National Forests Utah. We identified effect each species using fencing allowed for deer-only, native only (deer elk), all a complete exclosure. Over year period (2013–2016) we quantified impacts height, density, browse rates trap photos. Ungulate activity nearly 10-fold higher two compared third, gradually decreased over time. Meristem removal unfenced plots sites averaged 60% as critical threshold point failure. All had significant similar regeneration success, but when adjusted differences estimated forage intake (animal unit months), became apparent (deer > elk > cattle). 4 cattle per camera−1 day−1 2.5 deer or elk sufficient reach apical meristems. conclude differentially influence recruitment, browsing above 30% meristem impairs with failure occurring loss.