Submitted to: Journal of Sustainable Forestry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2002
Publication Date: 1/1/2003
Citation: BURNER, D.M., ARES, A. ICE DAMAGE IN AGROFORESTRY PINE PLANTATIONS IN ARKANSAS, USA: A CASE STUDY OF THREE CHRONOSEQUENCES. JOURNAL OF SUSTAINABLE FORESTRY. 2003. V. 17(3). P. 21-36. Interpretive Summary: An ice storm of historical magnitude struck west central Arkansas on December 24, 2000, depositing up to 2" of ice in some areas. Ice damages pine trees by the heavy weight load imposed on the tip, branches, and trunk. The economic impact of this storm on forests was disastrous, with early estimates of about 68,000 acres of private, nonindustrial timber completely lost, and another 135,000 acres damaged. We measured severe (breakage) and temporary (bending) effects of the ice storm in stands of loblolly pine that were 7-, 9-, and 17-years-old. The rate at which bent trees straightened was of particular interest because few researchers have examined this aspect of recovery. The three age classes had different types of ice damage. In the young stand, trees at a wider spacing tended to break while those at closer spacing tended to bend. Only 1 in 10 young trees was straight after the storm, but about half were straight 8 months later. This recovery occurred faster than might have been predicted based on tree size and amount of bending. Tree size and thinning became more important in influencing damage to older stands. Forests must be managed differently as they age to minimize their susceptibility to ice damage. This information will be useful for tree producers, consultants, and researchers in loblolly pine production areas that are susceptible to ice storms.
Technical Abstract: Acute (broken and leaning) and transient (bending) damage to loblolly pine (Pinus taeda) were assessed in three experimental agroforestry plantations following a December 2000 ice storm. Stand ages were 7-, 9-, and 17-yrs and ranged from 150 to 3,360 trees/ha in rectangular and cluster configurations. Wider tree spacing or lower stand density of 7- yr-old trees increased stem breakage, while closer spacing increased bending. Damage was not associated with height or diameter. Stems of 7- yr-old loblolly pine were remarkably flexible under ice loading and were capable of substantial recovery 8 mo after the storm. Straightening of bent trees was determined more by degree of initial bend rather than height or diameter. Damage to the 9-yr-old stand was correlated with height and diameter, but loblolly and shortleaf pine (P. Echinata) did not differ in damage (P<0.05). Thinning a 17-yr-old stand from above increased its susceptibility to ice damage 2-yr afterward compared to an unthinned stand. Planting design can minimize ice damage early in the rotation. Stand management becomes increasingly important in older stands when ice damage is associated with tree size and thinning strategy. This study supports the cultivation of loblolly pine in regions prone to ice damage.