Loblolly pine (Pinus taeda L.) is the most widely planted pine species in the southeastern United States and provides habitat for many species of conservation concern, including the federally protected red-cockaded woodpecker (RCW; Picoides borealis).  In Fort Benning, GA, approximately 2/3 of the RCW groups currently depend on loblolly pine stands.  Several studies have suggested that loblolly pines in the area are exhibiting abnormally high mortality, which may risk the sustainability and restoration of RCW on the installation. The main objectives of the study are to evaluate the current status of loblolly pine health at Fort Benning and to identify possible causal factors negatively influencing loblolly health. We installed 89 plots (30 m x 30 m) in mature (> 38 years) loblolly pine forests.  In each plot, we measured aspect, slope, species, soil hardness, diameter at breast height, light exposure, and crown vigor class (CVC; 1 = good, 2 = fair, and 3 = poor). Stand age, site index, soil texture, and management history (burning and thinning) information was retrieved from existing inventory data.  

Results/Conclusions

Results show that most stands were generally healthy (54.4 and 2.9 % of loblolly pines in CVC1 and CVC3, respectively), while few were relatively poor (3 stands >20% loblolly pines in CVC3 and 8 stands >20% dead loblolly pines). Site index and soil hardness were positively and significantly correlated with % loblolly pines in CVC1 (r = 0.22, p = 0.04 and r = 0.29, p = 0.01, respectively) and negatively correlated with % loblolly pines in CVC3 (p = -0.19, p = 0.07 and r = -0.21, p = 0.05, respectively). Moreover, % loblolly trees in CVC1, site index, and soil hardness tended to increase in finer soils, while %CVC3 decreased in finer soil. The results suggest that crown health condition is significantly influenced by nutrient and/or water limitation. We did not observe any specific effect of slope and aspect on crown health.  Additionally, we did not find any relationship between management history and loblolly pine health.