Effect of Tree Shelters on Survival, Growth, and Wood Quality of 11 Tree Species Commonly Planted in the Southern United States

"One-year-old seedlings of 11 commonly used southern urban shade tree species were planted with and without plastic shelters and grown for 3 years (1993-1995) to determine shelter effects on tree growth, survival, and appearance. Shelters increased the percentage of survival of all species except Katsura tree (Cercidiphyllum japonicum). After 2 years, survival was approximately 85%, compared to 50% for nonsheltered trees, with sheltered sawtooth oak (Quercus acutissima), green ash (Fraxinus pennsylvanica), nuttall oak (Q. nuttallii), Chinese elm (Ulmus parvifolia), swamp chestnut oak (Q. michauxii), and northern red oak (Q. rubra) having at least 90% survival. Seventy percent of the sheltered and 88% of the nonsheltered trees that died did so during the first year of the study. Shelters increased height growth of sawtooth oak, green ash, white oak (Q. alba), nuttall oak, eastern redbud (Cercis canadensis), swamp chestnut oak, and northern red oak after 3 years. Shelters had a negative effect on basal diameter of flowering dogwood (Cornus florida) and Chinese elm during the first 2 years, and a positive effect on basal diameter of swamp chestnut oak in year 1. After 3 years, neither crown area, woody biomass, nor wood density were influenced by shelters. Due to increased survival and height growth, tree shelters may help in establishment of seedling sawtooth oak, green ash, Chinese elm, white oak, redbud, nuttall oak, swamp chestnut oak, and northern red oak in urban areas of the southern United States."