Ice Damage in a Chronosequence of Agroforestry Pine Plantations in Arkansas, USA

Acute (broken and leaning) and transient (bending) damage to loblolly pine (Pinus taedaL.) were assessed in a case study of experimental agroforestry plantations following a December 2000 ice storm. Stand ages were 7-, 9-, and 17-years-old and tree density ranged from 150 to 3,360 trees ha−1 in rectangular and multi-row configurations. Wider tree spacing or lower stand density of 7-year-old trees increased stem breakage, while closer spacing increased bending. There was substantial straightening of bent 7-year-old trees 8 months after the storm, and this recovery was determined more by degree of initial bend rather than height or diameter. Nine-year-old loblolly pine had 19% more top breakage and 59% more stem breakage than shortleaf pine (P. echinataMill.) (P < 0.001). Agroforestry design influenced ice damage in 7-year-old stands, but no design had catastrophic loss. Thinning from above caused an increased susceptibility of ice damage to a 17-year-old stand compared to a nonthinned stand. The c...