Study Reveals Loss Of California Trees Over 37 Years, Says They Might Not Be Back

Scientists have analysed California's tree cover reduction and how it changed, revealing in unprecedented detail the loss of trees over a 37-year period.

According to American Space Agency NASA, the US state is dependent on its trees to help decrease the amount of carbon dioxide in the atmosphere that contributes to global warming.

According to a study by the scientists from University of California, Irvine, trees in the state's mountain ranges and open spaces are dying due to wildfires and other pressures, and fewer new trees are replacing them.

The study was published in AGU Advancing Earth and Space Science on July 6 this year that analysed LANDSAT satellite data to describe how tree cover altered in California from 1985 to 2021, shrinking due to wildfires, logging, and droughts.

According to Science Daily, the research integrates remote sensing observations with geographic information to create yearly maps of vegetation cover (tree, shrub, and herbaceous) and disturbance type (fire, harvest, and forest die-off) across California from 1985 to 2021 at 30 m resolution.

"The forests are not keeping up with these large fires," said study co-author James Randerson, the Ralph J. and Carol M. Cicerone Professor of Earth system science at UCI. Since 1985, the state's total tree cover area has decreased by 6.7 percent. "These are big changes in less than four decades," he explained.

For the first time ever, the scientists have been able to quantify tree population reductions in California and connect them to factors like wildfires, drought stress, and logging, the research said. The scientists discovered that one of the most dramatic losses in tree cover occurred in Southern California, when 14 per cent of the tree population in nearby mountain ranges perished, probably permanently.