We need urban trees more than ever – here's how to save them from extreme heat
theconversation.com
New research reveals how trees respond to extreme heat. Most trees lose more water than models predict. Some species cope better than others. Access to water will be critical for the hot summer ahead.

We studied the effects of extreme heat on urban trees in Western Sydney during Australia’s record-breaking summer of 2019-20.

It can be hard to predict how individual trees will respond to heat stress.

As part of the latest research, we grew seedlings in a glasshouse to test how access to water affected heat tolerance.

In urban trees, leaves reached lethal temperatures of 49-50℃ for species with the lowest rates of water loss.

When species with low rates of water loss had access to water, there was little heat damage or scorched leaves.