Climate change threatens the survival of older forests and trees

Much of the U.S. has been warmer in recent years, affecting not only which trees are right for planting, but also threatening the survival of older forests.

A Yale Environmental 360 article by Bruce Dorminey reported the giant sequoias native to California’s Sierra Nevada are facing the looming effects of declining snowpack and rising temperatures.

Photo Credit: VisitSequoia.org

Photo Credit: VisitSequoia.org

Giant sequoias are the world’s largest living species, reaching heights of 300 feet and girths as large as 150 feet. Dorminey wrote, “some sequoias can live in excess of 3,000 years before being naturally toppled by a combination of weather and gravity.”

Giant sequoias have evolved and thrived for multiple millenniums. The species may have survived previous eras of climate change but Dorminey says U.S. government and university researchers claim the long-term existence of these trees might now be endangered as a result of the changing Sierra Nevada mountain snowpack and current changes to the climate.

Less moisture and longer, warmer summers make it difficult for giant sequoias, especially the seedlings and young trees with smaller root systems, to survive.

The complex interaction of rising temperatures and shifts in snowmelt and precipitation is slowly altering and threatening environments where certain tree species have evolved and thrived.

Warmer temperatures also pose the threat of insect infestations which have already killed spruce and pine trees across more than 70,000 square miles of western North America.

Dorminey presented research showing how older forests and trees have proven to be at greater risk to the effects of climate change.

A recent study published in the journal Science found that trees ranging from 100 to 300 years old, located across a wide range of global landscapes, were experiencing rising death rates. This study and other research found that higher temperatures and drier conditions have played an important role in tree mortality and forest drought stress across the continents.

hardiness zoneYou can see how regional climates have changed over the past few years by visiting the Arbor Day Foundation’s U.S. Hardiness Zone map which was developed based upon data from 5,000 National Climatic Data Center cooperative stations across the continental U.S.

 

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