Dynamics of forest composition and growth in Alabama of USA under human activities and climate fluctuation

Integrated analysis of forest dynamics under both anthropogenic influence and climatic change is crucial to indicating emergent patterns and meeting objectives of climate change mitigation. In this study, a long-term forest inventory data (1960s-2010s) in Alabama, USA were analyzed for patterns in relation to human activities and climate fluctuation. The results indicated that the species (or species groups) composition in Alabama’s forests was significantly different between all reported times, except for 2012–2015 based on Simpson’s index. Eastern hemlock trees declined dramatically. The overall forest communities became less homogeneous. Positive or negative correlation existed in the abundance of many species. The distribution of tree abundance along diameters for tree species followed exponential models. Both annual tree mortality and net growth rate increased from the 1960s. The total volume of growing stock increased from 14.4 million cubic feet in 1963 to 39.5 million cubic feet in 2016. The average volume of growing stock per acre also increased linearly with annual average air temperature, but not with annual precipitation. Based on the patterns of Alabama’s forests under climate fluctuation and human activities, some suggestions on developing strategies for the sustainability of Alabama forest were discussed.