3.5 Demographic History and Species Distribution Modeling
Based on ITS and cpDNA data, we performed mismatch distribution analysis and neutrality test to determine the demographic history ofNotholirion species. The mismatch distributions graphs for our study species were multimodal and/or very ragged instead of a smooth single-peaked curve, which indicates populations are stable and not shrinking or expanding (Figure 10) . In addition, the values of Tajima’s D and Fu’s Fs were non-significant for all Notholirionspecies in the neutrality test, which also means populations have not experienced expansion or sustained growth (Table 3) .
Considering Notholirion and climate scenarios (the LIG, the LGM, the present and the future), the area under the AUC value for the potential climatically suitable areas of Notholirion species was high (>0.95), indicating the highest predictive capacity. And the distribution ranges predicted for Notholirion species were consistent with the actual geographic distributions. Based on the modeling results, there are slight variations in both the overall distribution range and the optimal distribution range ofNotholirion across four different periods. The overall distribution range throughout these periods predominantly encompasses the HHM region, while the optimal distribution range (highlighted in red) is mainly concentrated in the Hengduan Mountains and along the margin of the QTP. The suitable distribution area of Notholirionon the eastern part of the Tibetan Plateau contracted significantly toward ITS eastern edge during the LGM period, and the main best distribution area shifted from the northern part of the Hengduan Mountains to the southern region. And from the LGM period to the present, the distribution area of Notholirion re-expands to the eastern part of the Tibetan Plateau. Predictions indicate that the future overall distribution range and optimal distribution area will not significantly differ from the present distribution (Figure 11) .
Table3 Results of the mismatch distribution analysis and neutrality tests forNotholirion