Spatiotemporal dynamics of Hemerocallis citrina habitat suitability in China under climate change scenarios

ObjectiveHemerocailis citrina, a perennial herb belonging to the Hemerocailis genus in the Apophaceae family, has been utilized as both food and medicine for thousands of years. Additionally, it is considered a traditional dominant cash crop in China. Therefore, analyzing the spatio-temporal distribution characteristics of climate sustability of H. citrina in current and future climatic conditions is crucial for its stable industry development in China. MethodENMTools was used to screen the data of 287 distribution points of H. citrina. 37 environmental variables affecting the distribution of H. citrina were selected, the MaxEnt model and Geographic Information System (ArcGIS) were used to simulate the potential distribution patterns of H. citrina in 5 periods (current, future 2040 s, 2060 s, 2080 s, and 2100 s), and the dominant climate factors affecting the distribution of H. citrina were analyzed through contribution rate, displacement importance value, and jackknife test. Results(1) The average AUC value of 10 cross-validated fits under the ROC curve for the training dataset was 0.933, and the average AUC value of 10 cross-validated fits for the test dataset was 0.901, this indicates that the simulation stability and reliability are highest when incorporating all three types of environmental variables. (2) The main environmental factors identified affecting their distribution include the lowest temperature of the coldest month, average temperature of the coldest quarter, slope, elevation, and carbonate or lime content, as determined by the contribution rate of cutting method, displacement contribution rate, and single factor response curve. (3) The model prediction showed that H. citrina was widely distributed in 34 provincial regions of China under the current climate conditions, with a suitable area of 646.81 km2. (4) Under the future emission scenarios, the suitable habitat for H. citrina is projected to shrink and not shift to higher latitudes, indicating a negative impact of climate warming on its distribution, which will reduce the suitable habitat and narrow the ecological niche. Temperature and precipitation have been identified as important factors affecting the distribution of H. citrina. Although H. citrinas suitable habitat is expected to decrease to varying degrees in the future, the distribution area is relatively stable and there will still be a broad natural habitat in the future. ConclusionThe species distribution model was used to predict the future temporal and spatial distribution of climate-suitable areas for H. citrina in China. Based on the models simulation results, it is recommended that north and southeast China become the main planting areas for H. citrina in the future, with Sichuan and other regions as key development areas. Additionally, other regions should prioritize developing suitable cash crops based on local conditions.