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