Effect of Seedling Size and First-Order-Lateral Roots on Early Development of Northern Red Oak on Mesic Sites
Northern red oak (Quercus rubra) seedlings were placed in three grades based on number of first-order-lateral roots. The grades were poor, medium, and good and had numbers of 0 to 6, 7 to 11, 12, and > 12, respectively. Eighty seedlings from each group were either underplanted or established in an adjacent clearcut on a high-quality mesic site in North Carolina. There were 240 seedlings outplanted on each area. The poor-graded seedlings were initially smaller than the medium and good seedlings with heights and root collar diameters of about 67 centimeters and 7.4 millimeters; 115 centimeters and 11.3 millimeters; and 138 centimeters and 13.4 millimeters, respectively. Survival was better overall with the underplanted seedlings at year 7, with the poor, medium, and good seedlings surviving at 75, 78, and 96 percent, respectively. Growth was unsatisfactory for all three grades. Survival on the clearcut was affected by a 17-year-locust (Magicicada septendecim L.) infestation and heavy stump sprout competition. Survival of the poor, medium, and good seedlings were 59, 63, and 66 percent, respectively. Height and stem caliper were very good for the medium and good seedlings. Only 3 seedlings from the 0-6 grade were free to grow at age 5, while 29 of the seedlings in the good grade were free to grow.