Planning Ginkgo biloba future fruit production areas under climate change: Application of a combinatorial modeling approach

Ginkgo biloba forests are widely studied for their fruits' high medicinal, edible, and economic values with an increasing global demand for its fruits supply. The impact of climate change on the habitat suitability of this species has been assessed in previous studies. This study was to address the climate change impact on both habitat suitability and fruit yield. We used fruit grain weight to represent fruit productivity and quality of Ginkgo fruit forests and related it to climate variables to develop a climate response function (Method I). Meanwhile, we also built a Maxent habitat suitability model and associated it with fruit grain weight (Method II). Results showed that Method I provided much higher prediction accuracy (R2 = 0.68) than Method II (R2 = 0.39). We combined Method I with the species habitat model to predict suitable production areas of Ginkgo fruit to achieve high fruit production within suitable habitats for the contemporary and future periods. We found that Ginkgo fruit grain weight was mainly affected by mean annual average temperature (MAT) and mean annual precipitation (MAP), while the degree-days below 0 celcius (DD < 0) was the main climate factor limiting the distribution of Ginkgo fruit forests suitable habitat. The combined model predictions showed that the suitable production areas of Ginkgo fruit forests are expected to decrease and move northeastward in the future under the Representative Concen-tration Pathway (RCP) 4.5 and 8.5 scenarios. Our predictions can be used to maximize Ginkgo fruit quality production while minimizing the risk of low survival in the planning of Ginkgo fruit forest production areas.