Increasingly severe disturbances weaken world’s temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world’s temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

“While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease these conversions,” said Constance Millar, lead author and forest ecologist with the USDA Forest Service’s Pacific Southwest Research Station.

Many forests are remarkably resilient, re-growing after years of logging. Yet, the researchers note from review of the enormous body of work on the subject, climate change and rising global temperatures are giving rise to “hotter” droughts—droughts that exhibit a level of severity beyond that witnessed in the past century. During a hotter drought, high air temperatures overheat leaves and also increase the stress on trees by drawing the moisture from their tissues at faster rates than normal. Snow that would normally act as emergency water storage for trees during the dry season instead falls as rain.

Sourced through Scoop.it from: phys.org

GR:  And there go the forests.  This is the third analysis this week that concludes forests will not do well as climate changes.

One thought on “Increasingly severe disturbances weaken world’s temperate forests

  1. “During a hotter drought, high air temperatures overheat leaves and also increase the stress on trees by drawing the moisture from their tissues at faster rates than normal.”

    That is what I’ve observed in the U.S. pacific northwest. Evergreens, in particular, appear to be suffering from the dry, hot anomalous conditions this year. Many brown needles can be seen on their interior branches, and the trees look more brittle than usual – not the soft, youthful, deep green that they should have even at this time of year.

    Like

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