4.2 Distribution changes
According to Figure 1, the reconstructed-suitable distributions for LIG
and LGM show that macaques were principally concentrated in the eastern
Southwest, Central, and Coastal. Such a distribution pattern
corresponded to the dispersal and radiation scenarios of the macaques
during the Pliocene and Pleistocene (Li et
al., 2020; He et al., 2022;
Zhang et al., 2022): Asian macaques
migrating from North Africa entered a Convergence-Divergence Center in
Southwest China through Europe and Western Asia aforementioned. They
then continued the dispersion and radiation along the three major rivers
in the East Asian continent (Yangtze, Yellow, and Pearl), reaching far
east Asia (Taiwan, Korea, and Japan). Others spread to Southeast Asia,
occupying Borneo, Malaysia, and Indonesia
(Li et al., 2020). However, as found in
this study, most taxa remain in Southwest China (Figure S1), where they
initiated dispersion and radiation in East and Southeast Asia
(He et al., 2022;
Zhang et al., 2022), implying that the
Southwest is still their central distribution region.
Compared to the LIG (Figure 1A), some highly suitable areas during the
LGM were degraded, especially in Northern China, the Sichuan Basin, and
the Qinling-Daba Mountain (Figure 1B). This change must have been
associated with the severe monsoon generating the cold and dry climate
during the Quaternary (Zhang, 2004),
following the rapid uplift of the Himalayan orogeny and the
Qinghai-Tibet Plateau. As a result, some animals, including primates,
survived the regions with relatively stable environments and ecological
niches during the Later Pleistocene
(Jablonski, 1993). Macaques
(Macaca ) reached Northern China, the northern limit of the
subtropic zone, during the Early or Middle Pleistocene
(Zhang, 2002). The distribution extended
northwards to the Liaodong Peninsula, northeast Beijing, and the
northernmost Jinniushan (Jablonski,
1993). What followed up was that tropical and subtropical forests
migrated southward from north to south China
(Huang et al., 2021), so macaques and
other primate species were pushed southern movement
(Jablonski, 1998).
Compared to LGM (Figure 1B), the size and regions of suitable
distributions of the current macaque distribution have reduced (Figure 2
and 3), so that they were prominently located in high mountainous areas
in the Yunnan-Guizhou Plateau in the Southwest, as well as alongside the
Qinling Mountains in southeastern Northwest, and southern Coastal and
Central (Zhejiang-Fujian). Such modified profiles, as mentioned above,
must have been caused by accelerated human-induced activities in China
during the Holocene, such as extensive deforestation and cultivation of
the lowlands (Olson and James, 1982;
Ma et al., 2020), which was accelerated
following further exploiting lands and indiscriminate deforestation,
particularly after the Qin and Han Dynasties
(Ramankutty and Foley, 1999). So after
1,700 BP, 5 million m2 of natural vegetation had been
converted into agricultural land and pasture
(Pongratz et al., 2008). Further, the two
opium wars (1800-1849 and 1850-1899), the Second World War (1939-1945),
the Civil War (1900-1949), and the post-war period (1950
~) aimed at increasing agricultural demands for the
rapidly increased human population, have caused a series of waves of
significant destroying natural environments and devastating animal
distributions (Pan et al., 2016;
Huang et al., 2021).
Over the last 40 years, the
unprecedented social-economic development has led to significantly
increasing road construction, cropland, and pasture – which, as
indicated in the study, would further push the macaques and other
animals to higher mountains.