Images reveal extent of hurricane damage to Puerto Rican forests

Nearly a year later, Puerto Rico continues to deal with the fallout of Hurricane Maria. 155 mile per hour winds swept across the island and caused torrential flooding, knocked out the power grid, downed trees and reduced many lush forests to debris.  

Researchers from the National Aeronautics and Space Administration (NASA) were able to get a full assessment of just how much damage Maria did to Puerto Rico’s tropical forests by comparing before and after images of forest cover taken one thousand feet in the air.

Satellites can only show much so when it comes to tree cover,and so researchers used a Goddard’s Lidar, Hyperspectral and Thermal Imager, or G-LiHT to grasp the full scope of the damage from the hurricane.

“From the air, the scope of the hurricane’s damages was startling,” said Bruce Cook, a NASA scientist who led the aerial campaign. “The dense, interlocking canopies that blanketed the island before the storm were reduced to a tangle of downed trees and isolated survivors, stripped of their branches.”

Earlier in 2017, the NASA team used G-LiHT to help show how tropical forests take over and regrow on abandoned land. After Hurricane Maria made landfall, the team went back and flew over the same tracks they had previously studied to understand how forests recover from major events.

In one region of Puerto Rico, 60 percent of the trees were uprooted or broken and on the on the slopes of El Yunque National Forest, trees lost one-third of their height.

“[Hurricane] Maria pressed the reset button on many of the different processes that develop forests over time,” said Doug Morton, a G-LiHT co-investigator. “Now we’re watching a lot of those processes in fast-forward speeds as large areas of the island are recovering, with surviving trees and new seedlings basking in full sunlight. Just seven months after the storm, surviving trees are flushing new leaves and regrowing branches in order to regain their ability to harvest sunlight through photosynthesis.”

How Puerto Rico’s tropical forests will recover in the long term is still up for debate and continual monitoring will offer unique opportunities to study forest recovery over a long time particularly with the help of instruments like G-LiHT.

“G-LiHT allows us to collect research data at the scale of individual trees across broad landscapes,” said Morton. “Forests from Alaska to Puerto Rico are constantly changing in response to climate warming and disturbances such as fire and hurricanes.”

Tropical forests provide important habitats for local ecosystems and tree damage can have wide-reaching implications which is also something the NASA study is investigating.

Some plants and wildlife may actually benefit from the reduced tree cover while others will suffer.

What’s so impressive about the study is the collaborative effort and initiative behind it. Now, the researchers can even expand beyond Puerto Rico and monitor other forest changes and recovery using the techniques and skills applied after the Hurricane swept through.

“It’s beautiful to see that so many federal agencies came together to collaborate on this important work because forests play a key role in everything from biodiversity and the economy to public health,” said Grizelle Gonzalez, a research ecologist with the U.S. Forest Service and project lead for the research plots in El Yunque.

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By Kay Vandette, Earth.com Staff Writer

Image Credit: NASA