Impact of local climate and large-scale climate drivers on the growth of Gmelina arborea Roxb. in a South Asian moist tropical forest

Key message

Tree growth of Gmelina arborea Roxb is mainly influenced by pre-monsoon temperatures and ENSO in a moist tropical forest of Bangladesh.

Abstract

The present study was conducted to investigate the impact of climate change on tree radial growth in a moist tropical forest of Bangladesh. A standard ring-width index chronology (RWI) of Gmelina arborea Roxb. was developed spanning the 92-year period from 1929 to 2020 using the standard dendrochronological technique. The association between climate variables and RWI was determined by employing simple Pearson's correlation. Pre- and post-monsoon maximum temperature (Tmax) had a strong negative impact on tree growth. Temperatures during the monsoon period however favored tree growth. Tree growth was also influenced by previous years’ temperature providing evidence of a lag effect on radial growth. On a spatial scale, tree growth was influenced by regional climate and sea surface temperatures of Ninö 3.4 region, indicating teleconnection between tree growth and large-scale climate phenomenon. If the negative relationship between temperatures and tree growth continues in future, it will have important implications for tropical forest tree biomass, since temperature is predicted to increase in the tropics. Future global warming is thus very likely to affect the carbon sequestration potential of tropical forests in the face of climate change.