Assessing the Impact of Hurricane Ivan on Aboveground Carbon of Coastal Forests in Perdido Bay, Florida

Abstract

Abstract Hurricanes can physically transform forestry ecosystems, leading to immediate and potentially long-lasting impacts on carbon dynamics. We compared the average carbon in trees (saplings, bole, stump, tops) and foliage pre (2001-2003) and post (2005-2007) Hurricane Ivan for different types of tree categories in the Perdido Bay watershed, Florida. We estimated a decrease of 74.51 and 17.82 metric tons/ha of aboveground carbon in hardwood and mixed plots after Hurricane Ivan, respectively. Softwoods gained 18.22 metric ton/ha of aboveground carbon in the post-hurricane period due to post-hurricane regrowth. Aboveground carbon decreased in stands with large (≥ 0.15m) and medium (≥ 0.12m) diameter at breast height (d.b.h.) by 22.74 and 30.22 metric tons/ha, respectively. Aboveground carbon in young (< 25y) taller trees (> 15m) decreased by 121.55 metric ton/ha of carbon immediately after the hurricane. The results of our log-linear regression model indicate that stand type (softwood/mixed/hardwood), height, physiographic class (deep sands/flatwoods/rolling uplands/small drains/swaps/bottomlands) along with the hurricane-affected status of the FIA plots were statistically significant (p ≤ 0.05) determinants of the carbon loss from the forest stands. Over the study period, there was a decrease of approximately 28.64% of aboveground carbon in trees and 62.15% of aboveground carbon in foliage. Softwood plots had 51.30% less aboveground carbon compared to hardwood plots, while plots in flatwoods and rolling uplands had 66.27% and 52.73% less carbon than bay and wet pocosins, respectively. Post-hurricane, the carbon in the trees and foliage starts to recover gradually, taking about 15 years to come back to the original status at the landscape level. Our study provides a framework for researchers and policymakers to assess the vulnerability of coastal forests in light of extreme weather events.