Mountains of Southern China as “Plant Museums” and “Plant Cradles”: Evolutionary and Conservation Insights

Abstract

The occurrence of areas or centers of endemism is commonly attributed to the existence of suitable refugia in which plant lineages survived while others evolved during the late Neogene and Quaternary global cooling. In China, several studies performed since the 1980s have identified the mountains of central and southern China as the main centers of endemism in the country. A recent work studied the patterns of endemism separately for palaeoendemics and neoendemics and found that these tend to be located in different mountain ranges. Whereas, young endemics are preferably located in the mountain ranges of the eastern fringe of the Tibetan Plateau (''plant cradles''), old endemics tend to occur in the mountains of central, south central, and southeastern China (''plant museums''), although there are some exceptions. This pattern seems to be related to the different geological history of the mountain ranges. The eastern fringe of the Tibetan Plateau clearly constitutes the ''evolutionary front'' of China, probably due to the uninterrupted uplift of the plateau from the late Neogene. In contrast, the relative tectonic stability in central and southern China during most of the Tertiary may have maximized the persistence of relict plant lineages. These results have significant implications in the conservation of the endemic flora, which are briefly discussed.

The rise of the Himalaya enforced the diversification of SE Asian ferns by altering the monsoon regimes

“…These areas may be the refuge of taxa adapted to less seasonal monsoon climates. These new findings suggest the need to study more extensively the impact of the rise of the Himalaya on the assembly and maintenance of biodiversity in SE Asia [64]. Previous studies were often focused only on genera that colonized the newly founded mountain ranges (e.g., [15,63,65]), whereas the impact on the plant diversity in the lower altitudes of SE Asia were widely ignored.…”

Diploid hybrid origin ofHippophaë gyantsensis(Elaeagnaceae) in the western Qinghai-Tibet Plateau

“…The changes could have brought closely related plant species that lacked complete reproductive isolation into secondary contact, enabling subsequent interspecific hybridization events (Liu et al ., ; Ma et al ., ), and created new habitats where novel hybrid species could become successfully established (Liu et al ., ; Sun et al ., ). However, in this, the most significant ‘evolutionary front’ in China (López‐Pujol et al ., ), only a very few homoploid hybrid species have been reported despite extensive sampling and analysis ( Pinus densata : Ma, Szmidt & Wang, ; Gao et al ., ; Ostryopsis intermedia : Liu et al ., ; Picea purpurea : Sun et al ., ). To explore the extent to which homoploid hybrid speciation has contributed to the high level of biodiversity in the QTP and adjacent areas (Myers et al ., ), more studies are needed to examine whether this mode of speciation also occurred in other groups (Abbott et al ., ).…”

The Subtropical Vegetation of Southwestern China

“…In Fig. a 'cradle') for vascular plants López-Pujol et al 2011b ). The mountains of the region have had a relatively stable long-term environment, now referred to as Pleistocene glacial refugia, harboring a number of Tertiary relict plants (Ying et al 1993 ;López-Pujol et al 2011a ;Qiu et al 2011 ).…”