Abstract

One-year-old seedlings of sawtooth oak, white oak, green ash and flowering dogwood were evaluated to determine the effect of tree shelters on survival, growth and gas exchange. Trees were grown under both field and container nursery conditions. Shelters had a significant impact on survival of field-grown trees, but not on containerized, nursery-grown seedlings. Overall survival was approximately 75 and 40% for sheltered and non-sheltered, field-grown trees, respectively. Sheltered plants had approximately a 90% survival rate and non-sheltered trees exhibited approximately 80% survival in a nursery situation. In the field, sheltered trees had greater height growth and biomass production than non-sheltered trees. However, sheltered plants exhibited a decrease in total biomass in the nursery study, the majority of which was reflected in an overall 62% reduction in root production in the sheltered trees. Photosynthesis of sheltered trees averaged 65% of non-sheltered trees and internal leaf CO₂ was approximately 11% greater in sheltered trees. Shelters appear to benefit field-planted seedlings by providing physical protection and shade therefore, enabling the tree to better survive stresses from ambient conditions. In nursery situations, shelters may only be helpful in training attractive trees with less labor.