Informing Producers in a Nontraditional Maple Syrup Region: Red Maple and Sugar Maple Production Parameters in Kentucky

Abstract

Abstract Maple syrup is an important nontimber forest product in the northern latitudes of North America but has regained popularity in more southerly regions, including Kentucky. We provide the first formal investigation of the relationships between tree attributes and sap production parameters for red maple (Acer rubrum) and sugar maple (Acer saccharum) in Kentucky. During the 2020 and 2021 maple syrup seasons, we monitored per-tap sap volume production and sugar content of seventy-five red maples and seventy-five sugar maples to understand regional trends in maple production. Positive interannual correlations (r = 0.69–0.71) for sap volume and sugar content indicated that individual-tree production was relatively consistent between years. Moderate to strong positive relationships between diameter at breast height (DBH) and both annual sap volume production and sugar content were identified for both species. Predictive equations for sap volume and sugar content based on dbh demonstrated satisfactory predictive power and probable generalizability to new data sets. Trends in sap volume production and sugar content during Kentucky’s maple syrup season indicated that maple syrup production is closely related to weather patterns and site and tree characteristics, and the tools developed in this study will aid regional practitioners with feasibility analyses, operational implementation, long-term planning, and sugarbush management. Study Implications: Maple syrup production has become more popular in southern states in recent decades. Our study tracked yearly sap volume production and sugar content (the measures that control syrup yield) for red and sugar maples across two seasons in Kentucky. We found that both sap volume and sugar content increased with DBH and can be satisfactorily predicted by DBH. Trees in dominant and codominant crown classes yielded higher syrup volumes than intermediate and overtopped trees. The tools developed by this study will aid landowners and foresters in estimating the potential maple syrup yield of southern sugarbushes.