Analyses assessing the stationarity of climate-growth responses are necessary to determine the impact of climate change on tree growth. An increasing number of studies investigated changes in tree growth sensitivity in the temperate and boreal forests, however, such studies are rare in tropical forests.
Pinus latteri (Tenasserim pine) is widely distributed in Southeast Asia and is considered as one of the most important tree species with respect to the reforestation of watershed areas and forest conservation.
In a study published in Forests, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) developed tree ring-width chronologies of Tenasserim pine at three sites from northwest to northeast Thailand and evaluated their climate-growth relationships.
The results revealed that tree growth of Tenasserim pine was predominantly limited by moisture availability during the transition season from April to June, with negative effects of temperatures and positive effects of precipitation and relative humidity.
Under the background of rapidly increasing temperature and decreasing precipitation and relative humidity, Tenasserim pine growing in the lowland area in northeastern Thailand became more sensitive to moisture availability during recent decades.
Intensified drought stress has resulted in an increasing growth synchrony among Tenasserim pines and a declining growth trends in the lowland area in northeastern Thailand.
They also detected an increasing growth trend at the high elevation site in northwestern Thailand, where the Tenasserim pine trees may suffer less water stress and benefit from the warming climate.
“Our results provide more insights into the variability of forest productivity of Tenasserim forests and raise the concerns of pine forest vulnerability in lowland Thailand under a changing climate”, said Prof. FAN Zexin, principal investigator of the study.
FAN Zexin Ph.D Principal Investigator
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China