An estimated 23 to 31 million trees were severely damaged in Puerto Rican forests after Hurricane Maria, according to a study published by the Lawrence Berkeley National Laboratory on March 1.
The study focused on the ecological damage inflicted on Puerto Rican forests by recent hurricanes, particularly Hurricane Maria. Scientists used data from the Landsat 8 satellite to compare images of the island from before and after Hurricane Maria, according to Robinson Negrón-Juárez, one of the co-authors of the study, and the study’s abstract.
They examined the individual pixels of these images to determine changes in nonphotosynthetic vegetation of the forests and calibrate the level of disturbance in the forests following the hurricane, according to Negrón-Juárez.
“To each level of disturbance, we assigned a percentage of tree mortality based on our previous studies in the Gulf Coast,” Negrón-Juárez said. “Therefore, our results about Maria are very preliminary, since we did not conduct field work.”
The study’s first author is Yanlei Feng, a doctoral candidate in the department of geography at UC Berkeley, and her corresponding author is Jeffrey Chambers, a faculty scientist in the climate sciences department at Berkeley Lab.
Though the study was not able to address the level of urban damage, the researchers found the overall ecological damage was considerable, according to co-author Jazlynn Hall, a doctoral student at Columbia University.
“The ecological damage that we observed was widespread and was in many places severe,” Hall said in an email. “We are currently planning to collect field estimates of tree damage and mortality that would give us a clearer idea of the overall ecological damage.”
According to Feng, the tree damage can manifest in many ways, including snapped and uprooted trees and tree canopies stripped of leaves. Hall added that the scientists are still determining the exact extent of the ecological damage.
Despite the widespread ecological damage, Puerto Rico’s forests will recover relatively quickly, according to co-author María Uriarte, a professor from Columbia University.
“Puerto Rico is different in the sense that its forests get hit by hurricanes pretty frequently, so species have adaptations to deal with these hurricanes,” Uriarte said. “This is an area that is extremely warm and gets a lot of rainfall, so the forest will recover relatively rapidly in this particular context.”
According to Feng, scientists will continue to examine the spatial variation of disturbance on the island and possible reasons for the variation.
With more frequent storms or continued climate change, however, the forests’ recovery could be more difficult, Hall added.
“The forests may very likely fix themselves from this specific hurricane,” Hall said in an email. “However, if hurricanes were to become more frequent or more intense, and if the effects of climate change were to exacerbate the damage and subsequent recovery, more may need to be done to help the forests recover.”