Tree Shelters Reduced Growth and Survival of Underplanted Red Oak Seedlings in Southern Iowa

A major concern in the management of northern red oak (Quercus rubra L.) is the difficulty in regenerating stands that have dense understories of shade tolerant species. A replicated study in southern Iowa indicated that over a 5 yr period, tree shelters have a major impact on establishment of underplanted, 1-0, northern red oak bareroot stock. Sheltered seedlings had increased height growth during the first 3 growing seasons. But during the next 2 growing seasons, annual height growth of sheltered seedlings declined to a level of annual height growth similar to that of nonsheltered seedlings. After 5 growing seasons, sheltered seedlings were approximately 30 cm taller than nonsheltered seedlings. Sheltered and nonsheltered seedlings were one-third to two-thirds the height of the shelters. At the end of the fifth growing season, total mortality for sheltered seedlings was 40 and 55%, whereas for nonsheltered seedlings, mortality was 26 and 28% at the McNay and Stephens sites, respectively. Tree shelters may be a viable alternative in open areas (e.g., clearcuts or plantations), but in this study, tree shelters reduced both growth and survival when used to protect underplanted, 1-0, red oak seedlings. North. J. Appl. For. 16(2):103-107.