World’s oldest Banyan tree scientifically dated found in Bihar: Indian government

A banyan tree in the eastern Indian state of Bihar, estimated to be around 700 years old, has been identified by researchers as the world's oldest scientifically dated banyan tree, the Science and Technology Ministry said on Friday.

Using radiocarbon dating, a method that relies only on scientific evidence rather than historical records or folklore, a team of scientists from Lucknow's Birbal Sahni Institute of Palaeosciences established that the nearly 700-year-old tree is likely a surviving remnant of a natural forest that once existed in the region, the Ministry said.

Traditionally, estimating the age of banyan trees relied on folklore, local stories or historical records, which were often inaccurate. These living representations of history were not scientifically dated previously due to a lack of a clear protocol, it pointed out.

Field sampling and laboratory analyses revealed that the absence of distinct annual growth rings in most tropical broadleaf trees limited the application of conventional dendrochronological techniques, emphasising the need for alternative high-precision dating methods, including radiocarbon dating.

When Dr Trina Bose of the Institute, an autonomous institute under the Department of Science and Technology (DST), was invited by the Bihar Forest Department to determine the age of the Munger banyan tree, she recognised the limitations of conventional dating approaches for tropical broadleaf species.

To address this challenge, she initiated the development of a new scientific approach for age determination. Dr Bose led a research team comprising Dr Mayank Shekhar and Dr Akhilesh K. Yadava, who collaboratively developed and applied an innovative methodology to establish the age of the tree, the Ministry said in a statement.

The research team extracted alpha-cellulose, the most stable primary component of plant cell walls, from wood samples collected near the pith of a secondary trunk and an ancient primary branch. The pith is particularly important because it represents the earliest wood formed during the juvenile stage of secondary growth.

The extracted cellulose samples were subjected to high-precision radiocarbon dating using Accelerator Mass Spectrometry (AMS), followed by calibration against the latest IntCal20 calibration curve and OxCal software, enabling the team to establish a robust, reliable estimate of the tree's age.

This finding refutes earlier assumptions that the Munger banyan was planted in front of the historic 'Burra Bungalow' building which, based on architectural style, dates to the late Mughal-Early British period (about 300 to 350 years old) as a venue for dialogue between rulers and common citizens, village assemblies, religious ceremonies and cultural exchanges.

The finding by the scientists' team establishes that the approximately 700-year-old tree is likely a surviving remnant of a natural forest that once existed in the region and that it witnessed the construction of the building. Hence, this analysis redefines the order of historical events in this region.

The research, published in the journal Quaternary Research, provides a scientific method for accurately dating heritage trees, helping governments, forest departments and conservation agencies identify and protect culturally and ecologically important trees.

It said: "The research represents a major breakthrough in the scientific dating of ancient trees in tropical regions and supports efforts to preserve natural, historical and cultural heritage throughout South Asia and beyond."