Open Collections

Abstract

Western hemlock seedlings were grown for 8 months in a greenhouse with fertilizer amendments of N, P, N+P, and lime. Humus material was used as a growth medium. It was collected from low-productive sites identified by Lewis (1985) as the cedar-hemlock phase of the Thuja plicata - Tsuga heterophylla - Gautheria shallon - Rhytidiadelphusloreus ecosystem association unit designated as S1CH , on his ecosystem maps of Tree Farm Licences 6 and 25, which are located on northern Vancouver Island. A combination of 100 kg/ha N and 150 kg/ha P produced the most favourable seedling growth and foliar nutrient status. N or P added separately at these rates also gave superior seedling growth compared to the control. Neither lime, nor high rates of N (at 300 kg/ha with or without P) increased seedling growth. High N additions also restricted root development. N fertilization reduced foliar P concentrations, and P addition decreased foliar N concentrations. Foliar Mg concentrations increased when P fertilizers were added. N and/or P additions caused a decrease in foliar B concentrations. A combination of N and P increased foliar Zn concentrations and S, but reduced Mn absorption. Foliar R was inversely related to seedling productivity. Management recommendations for the S1CH sites include fertilizing with P, and increasing available N either by cultivation to increase mineralization or by low rates of N fertilization