Developing management option for the survival and growth of Pinus patula in frost prone area

Ethiopia has made significant efforts to rehabilitate or restore degraded lands, but these efforts have been hampered by low soil fertility and extreme seasonal frost. Since frost damage is most severe during the early stages of seedling establishment and development, it is crucial to prioritize research on suitable silvicultural management practices that enable rapid establishment and growth of young trees in frost-prone regions. The study aimed to identify effective silvicultural practices for improving seedling survival in frost-prone regions. The experiment was conducted using a randomized complete block design with three replications. The treatments included vegetative mulches with watering, watering alone, application of triple superphosphate at planting (200 kg ha− 1), 150 kg ha− 1 urea, and 100 kg ha− 1 urea (applied at 6, 12, 18, and 24 months after planting), spraying copper compounds to control INA bacteria concentrations, physical barriers to control cold air drainage, and a control. The results reveal that mulching with watering and watering alone are the best silvicultural seedling management practices in frost-prone areas. These two silvicultural management practices resulted in a 34% increase in height, root collar diameter and seedling survival rate compared to the control at three years’ age of seedling. The height and root collar diameter of Pinus patula seedlings managed with watering only and with mulching plus watering were 77 and 66 cm in height, and 2.03 and 1.93 cm in diameter, respectively. In contrast, the control seedlings measured 49.0 cm in height and 1.3 cm in diameter. Seedling survival reached 83% that was managed by mulching with watering by reduce the impact of frost damage. Mulching with watering and watering only have a positive effect on mitigating the impact of frost. We recommend further investigations to optimize the growth performance of Pinus patula. Additionally, evaluating the effects of triple superphosphate + urea and copper compound treatments under controlled environments would provide valuable insights.