3.5 Changes in Spatial Pattern of Potential Suitable Areas
of T. sinense
Compared to the current period, the suitable area for T. sinense decreased from the last interglacial period to the mid-Holocene,
followed by an increase (Fig. 6). During the mid-Holocene, an additional
area of approximately 119,693.5 km2 emerged,
constituting 17.72% of the total area. These additions were mainly
concentrated in central Yunnan and southern Gansu. Conversely, during
the last glacial period, the cold climate led to a significant reduction
in suitable habitats, resulting in a loss of 42,620.2
km2, or a 6.3% decrease (Table 5). Losses occurred
predominantly in fragmented areas at the junction of Sichuan, Yunnan,
Gansu, and Shaanxi provinces. Retention areas during the Last Glacial
Maximum were primarily situated in Southwest China.
The expansion rate for 2050 was lower than that for 2070 across eight
different climate scenarios with similar concentrations (Fig. 6). In the
2050s, the additional area for T. sinense initially expanded,
then contracted with increasing greenhouse gas emissions. Conversely, by
the 2070s, the additional area exhibited an upward trend with increased
emissions. Except for the SSPs2.6 scenario, the loss rate in the 2070s
was significantly higher than that in the 2050s (Table 5). Overall,
under future climate scenarios, fragmentation of potential distribution
areas suitable for T. sinense is expected to increase. Loss areas
will concentrate in the southern region of the current suitable area,
while added areas will primarily occur in the north. These areas require
close monitoring for potential pattern changes.