3.3 Distribution range of the suitable areas of T.
chinense under current climate conditions
Under the current climate conditions, the suitable area of the complete
ecological niche of T. chinense is mainly distributed in three
vegetation areas (Boreal forest, Temperate seasonal forest, and
Shrubland) in the eastern of Asia (Figure 4A). The total area of
suitable areas is about 734.53 * 104 km2, among which the high, medium,
and low suitable areas are about 280.89 * 104 km2, 174.02 * 104 km2, and
279.62 * 104 km2, respectively. In China, the total area of the suitable
areas of T. chinense is 509.26 * 104 km2, mainly distributed in
the humid and semi-humid areas, with a small amount of distribution in
the semi-arid area of northeast China (Figure 4B). The high suitable
areas of T. chinense in China is approximately 273.72 * 104 km2,
mainly distributed in the subtropical evergreen broad-leaved forest
region, the warm temperate deciduous broad-leaved forest region, the
temperate grassland region and the temperate coniferous and deciduous
broad-leaved mixed forest region, accounting for 99.82% of the total
area of high suitable areas, and a small amount of the tropical monsoon
forests, rainforest region and the cold temperate coniferous forest
region; The medium suitable areas are distributed around the high
suitable areas, from the south to the subtropical evergreen broad-leaved
forest region from the north to the cold temperate coniferous forest
region were distributed in large numbers, with an area of about 131.00 *
104 km2; The low suitable areas is about 104.54 * 104 km2, which is
mainly distributed in the subtropical evergreen broad-leaved forest
region, the temperate grassland region and the high cold vegetation
region on the Qinghai Tibet Plateau, accounting for about 36.82%,
27.99% and 13.17%, respectively (Figure 4C).