Trees on the streets of Montreal in Canada benefit from leaky pipes
Catherine Zibo/Shutterstock
Trees growing on city streets in Montreal have been found to be more resilient to drought compared to those in parks. The reason behind this resilience lies in an unconventional water source that street trees tap into – leaky pipes.
During periods of low rainfall, trees in parks tend to experience a more significant decrease in water levels and sap flow compared to their counterparts on the streets. To uncover the mystery behind this phenomenon, André Poirier and his team at the University of Quebec in Montreal studied trunk samples from Norway maple and silver maple trees in both park and street settings in Montreal.
By analyzing the levels of different lead isotopes in the trees, the researchers were able to trace the origin of the water source. Park trees showed signs of lead isotopes linked to air pollution, while street trees exhibited isotopes associated with lead water pipes made from metal sourced from nearby mines.
Street trees, which require approximately 50 liters of water daily, face challenges in accessing rainwater due to urban infrastructure. Instead, they seem to be benefiting from Montreal’s leaky pipes, which lose a staggering 500 million liters of water per day.
According to Poirier, planting trees on city streets not only adds to the aesthetic appeal but also ensures their survival due to the hidden water source. This discovery challenges the common belief that park trees would be healthier and highlights the significant water usage by street trees.
Speaking about the findings, Gabriel Filippelli from Indiana University emphasized the remarkable scale of water consumption by street trees and the unexpected source of their sustenance.
These findings were presented by Poirier at the Goldschmidt geochemistry conference in Prague, Czech Republic, on 8 July, shedding light on the unique adaptation of urban trees to their environment.
