The ingenious living bridges of India

When monsoon clouds bring pelting rains to the village of Tyrna, Shailinda Syiemlieh takes the nearest bridge to reach the opposite bank of a gushing stream. The bridge is no ordinary structure made of concrete and metal. Instead, it is composed of a single giant fig tree that sits by the riverbank, and the support that Syiemlieh walks over is a mishmash of aerial roots tightly knotted and woven together. The bridge is not only a part of the landscape, it is helping to support its ecosystem at the same time.

Tyrna lies just above the plains of Bangladesh in the north-eastern Indian state of Meghalaya, which hosts hundreds of these bridges. For centuries, they have helped the indigenous Khasi and Jaintia communities to cross swelling rivers in monsoons. "Our ancestors were so clever," says Syiemlieh, "When they couldn't cross rivers, they made Jingkieng Jri – the living root bridges."

Meghalaya hosts some of the wettest locations on Earth. The village Mawsynram, the world's rainiest place, receives an annual rainfall of 11,871mm (39ft) – that would be enough to submerge a typical three-storey house if deluged all at once. Nearby Sohra comes second, averaging 11,430mm (37.5ft). From June to September, monsoon winds sweep north from the Bay of Bengal, passing over the humid plains of Bangladesh. When these air currents meet the hilly terrain of Meghalaya, they break open – and torrential rains begin.

When monsoon downpours periodically isolated the remote villages of Syiemlieh's ancestors from nearby towns, they trained living aerial roots of Indian rubber fig tree (Ficus elastica) to form a bridge across flooding rivers.

Researchers consider these living root bridges as an example of indigenous climate resilience. Aside from the connectivity they provide, these bridges attract tourists and help local people earn an income. Meanwhile, as researchers have found, they have regenerative effects on the surrounding environment. Scientists hope this concept of indigenous living architecture can help modern cities adapt better to climate change.