OXYGEN IN WATER CULTURE INFLUENCES GROWTH AND NUTRIENT UPTAKE OF JACK PINE, BLACK SPRUCE AND WHITE SPRUCE SEEDLINGS

Abstract

Seedlings of white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) showed significant reductions in all measures of growth and vitality at the 2.0 ppm O₂ level (27% saturation), and relatively low values for root lengths and root length/shoot length ratios at the 3.3 ppm O₂ level (44% saturation). Nitrogen was marginally deficient in white spruce needles in the 2.0 ppm treatment. Foliar N and K attained lower values for all species in the 2.0 ppm O₂ treatment, whereas Mg, Ca and Fe generally attained highest values at 2.0 ppm O₂. Similar measures of growth, vitality and foliar nutrient concentrations were obtained for 4.5, 5.4 and 7.5 ppm O₂ (60, 72 and 100% saturation), indicating that all these levels provided optimal aeration. Differences in measures of growth, vitality and foliar nutrient concentration suggest that the order of species tolerance to poor aeration from greatest to least is black spruce, jack pine and white spruce.