Development of Growth-Based Nectar Yield Models and Stand-Level Honey Production Estimates for Robinia pseudoacacia Stands

This study was conducted to develop nectar yield models and quantify potential honey production in Robinia pseudoacacia (black locust) stands, a major melliferous tree species in temperate regions. Growth, flowering, and nectar characteristics were measured for 21 R. pseudoacacia trees in Hwasun and Gwangju, Republic of Korea. Nectar yield models were constructed using diameter at breast height (DBH), root collar diameter (RCD), tree height (H), and tree age as predictors. Mean nectar volume per flower was 1.57 µL in Gwangju and 1.09 µL in Hwasun, whereas nectar sugar content per flower was 0.65 mg and 0.71 mg in Gwangju and Hwasun, respectively. Nectar yield per tree was significantly and positively correlated with all growth variables, with DBH showing the strongest correlation. The DBH-based model was developed as Y = 137.914(e−0.202(DBH))6.808, and the height-, RCD-, and age-based models followed logistic functions with coefficients of determination (R2) ranging from 0.77 to 0.90. By integrating the DBH-based model with an existing stand yield table, honey production was predicted ranging from 13.4 to 74.8 g per tree and 23.6 to 57.8 kg per hectare across stand ages of 10–60 years. These models provide a quantitative framework for assessing honey production potential of R. pseudoacacia stands and support decision-making in apiculture and melliferous resource management under changing climatic conditions.