Risk and damage of southern pine beetle outbreaks under global climate change

This study, using the panel data modeling approach, investigates the relationships between climatic variables and southern pine beetle (SPB) (Dendroctonus frontalis Zimmermann) infestations and assesses the impact of global climate change on SPB infestation risk and damage. The panel data model alleviates possible collinearity among climatic variables, accounts for the effect of omitted or unobserved variables, and incorporates natural and human adaptation, thus representing a more robust approach to analyzing climate change impacts. SPB outbreaks in Louisiana and Texas appeared to move together; infestations in Alabama, Arkansas, Georgia, Florida, Mississippi, South Carolina, North Carolina, and Tennessee were highly correlated; and Virginia demonstrated its unique temporal pattern of SPB outbreaks. Salvage harvest was found to be helpful in lessening future infestation risk. Warmer winters and springs would positively contribute to SPB outbreaks with spring temperature showing a more severe and persistent impact than winter temperature; increases in fall temperature would ease SPB outbreaks; and summer temperature would have a mixed impact on SPB infestations. Compared to temperature, precipitation would have a much smaller impact on SPB infestations. While increases in the previous winter, spring, and fall precipitation would enhance SPB outbreak risk in the current year, a wetter summer would reduce infestations 3 years later. Global climate change induced by doubling atmospheric CO2 concentration would intensify SPB infestation risk by 2.5-5 times. If the changes in the area and productivity of southern pine forests due to climate change are accounted for, SPB would cause even more severe damage, 4-7.5 times higher than the current value of trees killed annually. (C) 2003 Elsevier B.V. All rights reserved.