Shifts in species distributions have been documented in response to recent climatic change, with most species moving poleward and to higher altitude. However, different taxa may respond to climatic change differently. 

Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) conducted surveys of forest plots along an altitudinal transect in Natma Taung National Park (NTNP), Myanmar, a mountainous area located in the southeastern Himalayas with altitude ranging from 740 m to 3074 m a.s.l. 

They assessed the range dynamics of 20 tree species, by using the abundance and mean tree diameter and the ratio of juveniles to trees along an altitudinal transect (2450 m–3070 m) in a montane forest located in the southeastern Himalayas in Myanmar. They also compared the suitable range sizes of tree species of different range dynamics category. 

The data on tree distributions suggest that many species have responded to climate warming by upward range extension, whereas others have shown no range shifts.  

Furthermore, species from lineages of tropical origin were more likely to show upward shifts than species of subtropical or temperate origins. Most of the upward-extending species were of tropical origin, while the non-upward species belonged to lineages with a deep evolutionary history in subtropical or temperate regions. 

“Generally, our study supports the Climatic Variability Hypothesis (CVH), range dynamics of species belonging to lineages with a deep evolutionary history in high-latitude regions (which also had larger range sizes) were shown to be less responsive to climatic change than those of species from tropical lineages, which also had smaller geographic range sizes”, said Tluang HmungThang, a student from Southeast Asia Biodiversity Research Institute (SEABRI) of Chinese Academy of Sciences. 

The study entitled “Tree species of tropical and temperate lineages in a tropical Asian montane forest show different range dynamics in response to climate change” has been published in Global Ecology and Conservation. 

Contact 

CHEN Jin  Ph.D Principal Investigator 

Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China