El Yunque National Forest is notable not only for its beauty but for its incredible biodiversity.
Puerto Rico is a verdant Caribbean jewel with lush tropical flora that you can immerse yourself in when visiting El Yunque, one of America’s most biodiverse national forests. Nearly forty percent of its trees are native to the island and ten percent can be found nowhere else in the world. The origin of its name either derives from “white lands” in Taino or “anvil” in Spanish. Either way, it’s a deeply awe-inspiring place. And it’s still recovering after hurricanes Irma and Maria ripped it apart.
Botanist Dr. Amelia Merced felt the forest’s losses acutely.
On her first post-hurricane visit to El Yunque Amelia was emotionally crushed in a way that mirrored the devastated landscape around her. The thick canopy of Tabonuco, Sierra Palm and Palo Colorado that once provided shade for the understory and a home for abundant epiphytes – non-parasitic organisms that grow on the surface of larger plants – was gutted beyond recognition. Intense sunlight was now reaching the forest floor and changing its composition. Massive landslides had demolished huge swaths of trees, plants and wildlife. Amelia thought the forest might never return to its former glory and biodiversity.
“It was really heartbreaking,” says Amelia. “The first time I visited the forest and saw it stripped of its greenery; upturned rocks and soil and fallen trees everywhere. As a botanist, this was an extremely painful experience for me.”
But on a subsequent visit a few months later, she was astonished to see how much the forest had recovered.
“The forest is growing and regenerating and becoming a new thing,” she says, “Or maybe the same thing in a different way. I have seen so many encouraging signs of the forest’s resilience.”
The foliage in El Yunque’s canopy is coming back, providing shade and a foundation for many other plants and animals. Several species of palm trees have proliferated since the storms, as well as tinier plants on the forest floor like the bryophytes Amelia studies.
Pictured is one type of bryophyte, the philonotis.
Bryophytes are small flowerless mosses and liverworts that don’t have a root system but produce their own food using photosynthesis. They are often literally overlooked because they are so miniscule and don’t provide a source of food. But one could argue that bryophytes have true superpowers. They are extremely efficient at getting the water they need from precipitation and humidity. They reproduce quickly, use minimal resources and help clean the air of pollutants. They go dormant without enough water and revive when water again becomes available. But here is the coolest part – unlike most other plants, some bryophytes don’t decompose easily and release their carbon when they die. They store water and nutrients and pass them on to neighboring mosses for their good use. Bryophytes might just be the greatest unsung heroes of the plant kingdom.
Someday bryophytes could provide ways to help scientists combat climate change, which is one reason Amelia’s current project is so important. She is preparing a comprehensive guide to the common bryophytes of Puerto Rico with information about the critical role they play in forest health. She is also collaborating with a colleague who is working to preserve an endangered orchid that grows from bryophytes. Who knows? In the science-fiction future bryophytes could even be among the plant species humans might take into outer space as a key element of a broader long-term subsistence strategy.
“Plants are very smart,” Amelia says. “They just work their magic in a different way from humans. We can learn so much from them and they are critical to our survival.”