Climatic suitability of <i>Pyrus ussuriensis</i> in Northeast China under climate change scenarios.

To examine the distribution characteristics of <i>Pyrus ussuriensis</i> in Northeast China and its response patterns in the context of climate change, we analyzed the main factors influencing the distribution of <i>P. ussuriensis</i> and simulated its distribution in the Northeast China during different periods, with the maximum entropy model (MaxEnt) and the distribution data of <i>P. ussuriensis</i> in Northeast China (Heilongjiang Province, Jilin Province, Liaoning Province), and environmental data for the current period (1970-2000), the 2030s (2021-2040), and the 2050s (2041-2060) (including climate factors, topographic factors and soil factors). The results showed that the model passed the receiver operating characteristic curve (ROC) test, with the average area under the ROC for the training set being 0.925, showing high reliability in predicting the climatic suitability of <i>P. ussuriensis</i>. Out of 50 factors, 17 factors were identified as dominant factors, including climate, terrain, and soil factors. The contribution rate of climate factor was the most significant, accounting for 78.5% of the total. Under the current climate scenario, the highly suitable growth area of <i>P. ussuriensis</i> was distributed in central Anshan, central Liaoyang, eastern Yingkou, central Jinzhou, Chaoyang, Huludao, Fuxin in Liaoning, and the area of the highly suitable area was 0.78×10⁴ km². Under the future climate scenarios (2030s and 2050s), the suitable distribution area showed a trend of expansion and northward migration, with the area of highly suitable area reaching its peak in the 2050s at 7.9×10⁴ km².