How Strong Are Tree Roots?

During the monsoon season in northeast India, gentle streams flowing through the area’s valleys suddenly become torrents, impossible to cross on foot. For 180 years, the solution has been to use nature to help construct living bridges. Local tribes have devised a way to thread rubber tree roots through the hollow canes of the Areca palm, patiently nurturing them for years until they grow into sturdy bridges.

Tribesmen in the Khasi Hills region of the Indian state of Meghalaya first tried building bamboo bridges across the raging streams, but over time they would rot and break amid the monsoons, and villagers would be stranded. The living root bridges have proved more resilient.

Root bridges over turbulent waters:

• It can take 15 to 20 years for the root bridges to connect the opposite banks of a river. Some root bridges are more than 100 feet (30.5 m) long and can support the weight of 50 people.
• Over time, root bridges grow stronger, and rarely require maintenance. The strongest root bridges are more than 100 years old.
• The practice has been dying out over the past 25 years. Bridge builders today more frequently use steel rope and modern construction methods.