Some effects of soil type and water regime on growth of tupelo seedlings
Two—year—old swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) and water tupelo (N. aquatica L.) grown in large tanks in a silty clay loam soil from a river swamp or a sandy loam soil from a non—alluvial headwater swamp were subjected to continuous flooding at depths of 20 cm above the soil surface with moving water, 20 cm above the soil surface with stagnant water, or at the soil surface with moving water. Height growth of water tupelo averaged 1.8 times greater and dry weight 2 to 3 times greater in the more fertile soil from the river swamp than in soil from the headwater swamp. Soil type had no effect on growth of swamp tupelo. Growth and dry weight of both tupelos were poorest in the regime with stagnant water, which also had the highest CO_2 and lowest O_2 contents. Swamp tupelo grew 50 cm more in height in the surface—flooded regime with moving water than in either deep—flooded regime. Water tupelo in both regimes with moving water grew 37 cm taller than those in the stagnant regime.