Tree-ring δ18O climate signals vary among tree functional types in South Asian tropical moist forests

Islam M, Rahman M, Gebrekirstos A, Bräuning A (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Science of the Total Environment Elsevier

Book Volume: 756

Article Number: 143939

DOI: 10.1016/j.scitotenv.2020.143939

Abstract

We present the first annually resolved and statistically reliable tree-ring δ¹⁸O (δ¹⁸OT) chronologies for the three South Asian tropical moist forest tree species (Chukrasia tabularis A. Juss., Toona ciliata M. Roem., and Lagerstroemia speciosa Roxb.) which differ in their shade tolerance and resistance to water stress. We found significantly higher mean δ¹⁸OT values in light-demanding T. ciliata than in intermediate shade tolerant C. tabularis and shade tolerant L. speciosa (p < 0.001). δ¹⁸OT in C. tabularis was mainly influenced by pre-monsoon vapor pressure deficit (VPD; r = −0.54, p < 0.01) and post monsoon maximum temperature (Tmax) (r = 0.52, p < 0.01). δ¹⁸OT in T. ciliata was strongly negatively correlated with a dry season drought index PDSI (r = −0.65, p < 0.001) and VPD (r = −0.58, p < 0.001). Pre-monsoon Tmax was strongly positively linked with δ¹⁸OT in L. speciosa (r = 0.65, p < 0.001), indicating that climatic influences on δ¹⁸OT are species-specific and vary among tree functional types. Although there was a week correlation between local precipitation and δ¹⁸OT in our studied species, we found a strong correlation between δ¹⁸OT and precipitation at a larger spatial scale. Linear mixed effect models revealed that multiple factors improved model performance only in C. tabularis, yielding the best model, which combined VPD and Tmax. The top models in T. ciliata and L. speciosa included only the single factors PDSI and Tmax, highlighting that the way C. tabularis interacts with climate is more complex when compared with other two species. Our analyses suggest that stable oxygen isotope composition in tree rings of South Asian tropical moist forest trees are a suitable proxy of local and regional climate variability and are an important tool for understanding the physiological mechanisms associated with the global hydrological cycle.

Authors with CRIS profile

Mahmuda Islam Institut für Geographie Mizanur Rahman Lehrstuhl für Geographie (Physische Geographie) Achim Bräuning Lehrstuhl für Geographie (Physische Geographie)

Involved external institutions

World Agroforestry Centre

Kenya (KE)

How to cite

APA:

Islam, M., Rahman, M., Gebrekirstos, A., & Bräuning, A. (2021). Tree-ring δ18O climate signals vary among tree functional types in South Asian tropical moist forests. Science of the Total Environment, 756. https://dx.doi.org/10.1016/j.scitotenv.2020.143939

MLA:

Islam, Mahmuda, et al. "Tree-ring δ18O climate signals vary among tree functional types in South Asian tropical moist forests." Science of the Total Environment 756 (2021).

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