A 338-year tree-ring oxygen isotope record from Thai teak captures the variations in the Asian summer monsoon system

Abstract

A 338-year oxygen isotope record from teak tree-ring cellulose collected from Mae Hong Son province in northwestern Thailand was presented. The tree-ring series preserves the isotopic signal of the regional wet season rainfall and relative humidity. Tree-ring δ 18 O correlates strongly with regional rainfall from May to October, showing coherent variations over large areas in Southeast Asia. We reconstructed the summer monsoon season (May to October) rainfall based on a linear regression model that explained 35.2% of the actual rainfall variance. Additionally, we found that in the 19 th century, there was a remarkable drought during many years that corresponded to regional historic drought events. The signals of the June to September Indian summer monsoon (ISM) for the period between 1948 and 2009 were clearly found. Spatial correlations and spectral analyses revealed a strong impact of the El Niño-Southern Oscillation (ENSO) on tree-ring δ 18 O. However, ENSO influenced the tree-ring δ 18 O more strongly in the 1870-1906, 1907-1943, and 1944-1980 periods than in the 1981-2015 period, which corresponded to periods of weaker and stronger ISM intensity.

Stable Isotopes in Tree Rings of Pinus heldreichii Can Indicate Climate Variability over the Eastern Mediterranean Region

“…Indeed, several recent studies confirm that δ 18 O values can be a robust and reliable indicator of drought conditions and/or extreme hydroclimatic events [57,60,61]. We confirmed that δ 18 O values are tightly correlated with JJA precipitation sum over the substantial part of the Balkan Peninsula.…”

“…The ratio of photosynthetic CO 2 uptake to stomatal conductance, both of which are physiological processes contributing to carbon discrimination, is defined as plant water use efficiency (WUE). Accordingly, δ 13 C values of tree-ring cellulose are thought to provide particularly important insights into the tree's WUE and other related physiological processes [7,56,57]. However, it is not possible to determine whether a change in WUE is caused by carboxylation, stomatal conductance, and/or a combination of the two.…”

Teak Tree-Ring Cellulose δ13C, δ18O, and Tree-Ring Width from Northwestern Thailand Capture Different Aspects of Asian Monsoon Variability

“…Alpha-cellulose was extracted following the method described by Wieloch et al [28]. A detailed process for the alpha-cellulose extraction is described by Pumijumnong et al [29]. We extracted the alpha cellulose for each annual ring separately instead of pooling the individual samples.…”

Stable Isotopes in Tree Rings: Inferring Physiological, Climatic and Environmental Responses

“…Because some trees incorporate the δ 18 O signature of rainwater in stem wood, time series of tree-ring δ 18 O can be used to quantify past variability in precipitation. Tree-ring δ 18 O has been correlated with basin-wide precipitation in the Amazon Baker et al 2015Baker et al , 2016), and regional precipitation in Thailand Pumijumnong et al 2020), Costa Rica (Anchukaitis and Evans 2010), India (Managave et al 2011b), Indonesia , Laos and Vietnam (Xu et al 2011), West Africa (van der Sleen et al 2015b, and central Africa (Colombaroli et al 2016). Particularly El Niño Southern Oscillation (ENSO) variability is often evident in δ 18 O sequences either from positive anomalies or negative ones ).…”