Simulated Cattle Injury to Planted Slash Pine: Combinations of Defoliation, Browsing, and Trampling

Cattle injure young pines by defoliating, browsing, and trampling them. Little is known about how these injuries at various levels and in various combinations will affect survival and growth of planted pines. Therefore, such injuries were simulated once on slash pine at 6, 18, and 30 months after planting by (1) hand clipping to remove needles, (2) clipping off the shoots, and (3) bending the stem at a right angle to the vertical. Survival was poorest when treatments were applied to seedlings within 6 months after planting, whereas mortality was low when older seedlings were treated. Only the severest treatments, especially combinations of injury, caused extreme mortality. Seedlings treated at 6 months after planting suffered greater reductions in height growth than did the older seedlings. Only the severest combinations of injury permanently reduced height growth.