A 700-year old Banyan tree in Bihar’s Munger just entered history books, here’s why

For centuries, the age of India’s ancient banyan trees has largely been a matter of folklore, local legends and historical records. Now, scientists have, for the first time, accurately dated one using radiocarbon analysis.

A banyan tree in Bihar’s Munger, estimated to be around 700 years old, has been identified as the oldest accurately dated banyan tree (Ficus benghalensis) using radiocarbon dating – a method based entirely on scientific evidence rather than oral histories or historical accounts, according to a PIB press release.

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They have also occupied a central place in India’s social and cultural life for centuries. Yet determining their age has remained a challenge.

Unlike many temperate trees, tropical broadleaf species such as banyans lack distinct annual growth rings, making conventional dendrochronological methods ineffective. As a result, age estimates have historically depended on folklore, local narratives or historical documentation, often leading to uncertainty.

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Recognising the limitations of existing dating techniques for tropical broadleaf trees, she initiated the development of a new scientific approach.

Working with Dr. Mayank Shekhar and Dr. Akhilesh K. Yadava, Dr. Bose developed and applied an innovative methodology to estimate the tree’s age.

The researchers extracted alpha-cellulose – the most stable primary component of plant cell walls – from wood samples collected near the pith of a secondary trunk and from an ancient primary branch. The pith was crucial because it represents the earliest wood formed during the tree’s juvenile stage of secondary growth.

The cellulose samples were then analysed using high-precision radiocarbon dating through Accelerator Mass Spectrometry (AMS). The results were calibrated using the latest IntCal20 calibration curve and OxCal software, enabling the researchers to establish a robust and reliable estimate of the tree’s age.

The findings also overturn a long-held assumption about the tree’s history. It was previously believed that the banyan had been planted in front of the historic Burra Bunglow, a structure dating to the late Mughal-Early British period, around 300 to 350 years ago, where rulers and common citizens gathered for discussions, village assemblies, religious ceremonies and cultural exchanges.

Published in the journal Quaternary Research, the study introduces a scientific framework for accurately dating heritage trees. The method could help governments, forest departments and conservation agencies identify and protect culturally and ecologically significant trees by replacing uncertain age estimates with reliable scientific evidence.

Researchers say the methodology can also be applied to other ancient tropical trees around the world, with potential applications in biodiversity conservation, heritage management, environmental education and studies of past climates and historical landscapes.

The research marks a significant breakthrough in dating ancient tropical trees, particularly culturally important species such as the banyan, and could strengthen efforts to preserve natural, historical and cultural heritage across South Asia and beyond.