- Bendy, woodless trunks and above-ground roots prevent palm trees from toppling during severe storms.
- Puerto Rico's palms recovered faster than other tree populations after Hurricane Maria in 2017, researchers found.
Last week, footage from Hurricane Ian slamming into Florida and South Carolina showed damaging winds and flying waves snapping and buckling trees. But as pines and oaks fell, most palm trees were able to bend with the wind and withstand Ian's punishing conditions.
That's because palm trees have distinctive features that make them resistant to storm damage, Maria Uriarte, a forest ecologist at Columbia University, told Insider.
Human-caused greenhouse gas emissions trap heat in ocean waters, which in turn causes more evaporation and pumps moisture into the air. As hurricanes pass over, they absorb that moisture, which fuels slower and wetter storms, like Hurricane Ian.
But even as storms strengthen, palm trees' bendy trunks and unique root systems continue to allow them to stand up to these tropical tyrants.
Palms are more closely related to grasses than other trees
Palms belong to the Arecaceae family, a group that emerged about 100 million years ago. There are 181 known genera and around 2,600 species.
While palms are technically trees, they're monocots, meaning they're more closely related to grass, corn, and rice than they are to other trees, according to Uriarte.
Monocots only have one cotyledon, or the part of the seed that grows into the leaves. Palm trees have a stem, with triangle-shaped leaves called fronds that grow from a point at the top, according to Uriarte.
"What happens during hurricanes is that they are very flexible, so they can move with the wind and the fronds tend to fall off, but they can grow very rapidly right after the storm passes," she said, adding, "That makes them very resistant to damage."
Palm trees' woodless trunks allow them to bend in the wind
Palm trees bend easily in the wind, thanks to their fibrous and fairly wet woodless trunks. "If you were to cut them, it's like a bundle of vessels that they use to move water and nutrients, and it's pretty soft," Uriarte said, adding, "That makes them very flexible."
This flexibility makes them well adapted to windy and hurricane-prone areas.
Not all palm trees are alike. Uriarte pointed to research in Miami after Hurricane Andrew that found that palm trees originating from hurricane-prone areas — mostly in the Caribbean — were much more resistant to hurricanes than palms that came from areas that did not have hurricanes.
"That's interesting, because that also suggests that this resistance to hurricanes has evolved over time and that is not the same for all palm trees," Uriarte said.
In hurricane-prone areas, palm trees are common at higher elevations. "I expect that part of that reason is that, as you go up the mountain, it gets wetter and palms like wet soil," Uriarte said.
Another explanation, she added, might be that high mountains get the brunt of the wind from hurricanes, and palms tend to be more resistant to wind than other types of trees.
Palm trees' slightly above-ground roots anchor them, even in flooded areas
Palm trees are hard to uproot. That's because they have unique root systems, which are made up of a large number of short roots, which spread across the upper levels of the soil and help anchor the trees in place.
In the photo above, a palm tree in Puerto Rico's El Yunque rainforest grows roots above the ground.
"They go into the ground, but part of the root is also above the soil and that means that they don't get bogged down by the flooded areas," Uriarte said.
Experts say palm trees are ultra-resilient
In 2017, Hurricane Maria slammed into Puerto Rico as a Category 4 hurricane with winds up to 155 miles per hour.
Uriarte has monitored tree growth and death across Puerto Rico for more than a decade. After Maria, she and her team went back to Puerto Rico to document the storm's damage. They found that the hurricane had killed or severely damaged an estimated 20 million to 40 million trees. The palm trees were able to bounce back more quickly than other trees populations after the storm, in part because palms take root quickly.
"All of the trees took a while to recover, but the fastest recovery was for the palms," Uriarte said, adding, "They're unique and very well adapted to withstand hurricanes."