Stronger hurricanes could decimate forests and accelerate climate change, warns study

El Yunque National Forest after Hurricane Maria, on October 4, 2017.

(CNN)When Hurricane Maria struck Puerto Rico in September 2017, it left devastation in its wake.

It took nearly 11 months to restore power across the island and five months to fully restore the island's main water service. Almost 3,000 people were killed, according to official estimates.
But beyond the human tragedy, a new study has found that Maria changed the makeup of the forests that cover more than half the island, with certain species declining after the storm and others increasing.
    And the research suggests this could be a portent of changes that could come to forests across much of the Atlantic Tropics, as climate change drives more powerful storms.
    One potential effect is that these forests, rather than being net carbon stores, could actually become net carbon emitters, adding more carbon to the atmosphere. In other words, as the forests increasingly become victims of climate change, they would also contribute to it.
    "Carbon dynamics after a storm are hard to understand but after a storm a forest loses a lot of carbon and then regains it as it regrows, so we're looking at the long-term average," said Maria Uriarte, of Columbia University's Earth Institute, who led the research.
    "If bad storms become the norm, if a storm of Maria's severity becomes the average storm in the Caribbean, we expect the forest will store less carbon because trees don't have time to get big. We expect the net balance to be negative -- that's not published yet but that's what our models are showing."

    Damage and recovery

    Uriarte has been studying Puerto Rico's trees for the last 15 years. She returned to the island three months after her namesake hurricane and saw the damage to the forests in person.
    "What was very striking is that, with tree species, there were winners and losers," she told CNN.
    "I've been here a few times since the hurricane, and the recovery is very quick. There is a lot of damage but there is regrowth coming in -- but the composition [of the forests] is definitely going to change."
    Maria hit Puerto Rico as a category 4 storm, with winds of more than 155 miles (250 kilometers) per hour, and up to 500mm (20 inches) of rain falling over 24 hours. Last year, researchers from the University of California, Berkley, used remote sensing techniques to estimate that Maria may ha