SNAPSHOT: Drought and Trees

Trees of medium height survive drought better than trees that are shorter or taller, according to a study in Environmental Research Letters.

The researchers, who included Professor Chuixiang Yi (Queens College, The Graduate Center, CUNY), found that forests with tree canopies around 18 meters — 59 feet, or about the height of a six-story building — are more resistant to long periods of hot, dry weather than either shorter or taller trees. The findings could help shape forest management in the era of climate change. 

“Hot-dry-induced forest mortality poses a significant global concern for the future as carbon dioxide continues to rise and the climate continues to warm,” Yi told Physics World.

A canopied dirt road lined with trees

One theory for why medium-height trees do best, according to Yi: Water has farther to travel from the ground to the leaves of tall trees, while short trees may not have long enough roots to get the water they need. The study used satellite imagery and tree trunk ring data to calculate leaf growth and tree mortality in the Southwest during a 2002 drought.

SNAPSHOT is SUM’s new afternoon science brief.