Sustainable livestock production in sub-arctic Alaska: Plant and soil responses to simulated intensively managed grazing

Managing a robust pasture ecosystem and optimizing available forage under sub-arctic conditions in interior Alaska is a challenge. The region is characterized by a short growing season, slow residue decomposition rates and undeveloped soils that are vulnerable to compaction and erosion. The goal of this research was to examine the relative and combined role of grazing mechanisms; herbivory, trampling, and manure/urine deposition on forage yield and soil health in sub-arctic pastures within a simulated intensively managed rotational grazing (IMRG) framework. A full factorial experiment of muskox (Ovibos moschatus) manure/urine deposition (M), simulated trampling (T), and herbivory (forage clipping) (H), and control (C) mimicking IMRG timing and intensity, was conducted at the Robert G. White Large Animal Research Station, University of Alaska, Fairbanks. The simulations were conducted on 48–1 m2 plots on hilltop and hill bottom pastures with different vegetation and soil types, over the 2014 and 2015 grazing seasons. The control represented a pasture absent of grazing and served as a comparison of the treatments to restorative rest of grazing land. Grazing treatments MH and MTH had a positive impact on forage yield, while T and MT had a negative impact compared to C (p