Study area
This study focused on three climate regions in Yunnan Province, southwest China (21°09′–29°15′N and 97°32′–106°12′ E). The three regions are similar in area, but differ greatly in climate, geography, and vegetation (Table 1). The southern region has a tropical monsoon climate and contains a tropical flora that was shaped by the strike-slip extrusion of Indochina plate. The northwestern region has a temperate climate and contains a temperate flora shaped by the uplift of the Himalaya-Tibetan Plateau. The central region has a subtropical climate and contains a subtropical flora with a combination of nearly equal proportions of species from both northwestern and southern floras (Zhu 2012; Liu et al. 2017). The overall floras of the regions combined are representative of East Asia (Zhu 2012; Liu et al. 2017).