Predicting the vulnerability of loblolly pine stands to decline in Fort Benning, GA

Fire exclusion has resulted in the replacement of historically dominant longleaf pine (LLP; Pinus palustris) with loblolly pine (LBP; Pinus taeda) throughout the southeastern U.S.  Fort Benning, GA has 36,400 ha of upland pine forests that are currently dominated by LBP.  Although LBP forests are considered inferior habitat for red-cockaded woodpeckers (RCW; Picoides borealis), a 2/3 of the base’s RCW population must use LBP for nesting and foraging due to a lack of mature LLP.  However, approximately 2/3 of the LBP stands experiences some level of decline that may negatively affect RCW habitats.  Therefore, it becomes urgent to develop management protocols to restore LLP, while retaining mature LBP to support RCW habitat.  In 2006, forest service conducted an extensive forest inventory on approximately half of the installation’s pine stands in Fort Benning.  We retrieved and analyzed plot level data from 745 of loblolly pine/hardwood, natural loblolly pine, and loblolly pine plantation stands to identify indicative variables of LBP decline.  The existence of hog ground damage or gopher tortoise burrows did not significantly (p = 0.05) affect the percentage of pine decline (%PD).  Number of hardwood trees larger than 35cm DBH showed significant (r = 0.46, p<0.01, n = 67) correlation with %PD in loblolly pine and hardwood stands, and herbaceous ground cover was significantly correlated (r = 0.12, p<0.01, n = 603) with %PD in loblolly stand.  Percent pine basal area (pine BA/total BA x 100) was significantly correlated with %PD (r = -0.32, p<0.01, n = 75) in loblolly pine plantations.