Plant biologists have discovered that a unique
The patchiness of the vegetation means soil nutrients also are unevenly distributed.
“And so the tree ferns seem to be putting out tentacles to sample the surrounding soils,” Dalling said. “They’re able to sample a greater range of nutrient environments for the same amount of investment of rootlets than if they just sent out a single rooting structure all around the fern. I think it’s all about the economics of how they use resources in a patchy environment.”
The tree ferns also grow very slowly.
“They’re probably putting on one or two leaves a year, and so they’re adding on the order of a few centimeters of height a year,” Dalling said.
This means each frond is a major investment of resources that the plant repurposes after the leaf dies. The slow growth also means that the tree fern is short enough that when its fronds die, they droop all the way to the ground. The trees reach a maximum height of about two meters, Dalling said.
The finding is “another example of the extraordinary diversity of plant adaptations that exist in resource-poor environments,” he said.
Reference: “Zombie leaves: Novel repurposing of senescent fronds in the tree fern Cyathea rojasiana in a tropical montane forest” by James W. Dalling, Evidelio Garcia, Carlos Espinosa, Camila Pizano, Astrid Ferrer and Jéssica Lira Viana, 18 January 2024, Ecology.
DOI: 10.1002/ecy.4248
Dalling also is a research associate at the Smithsonian Tropical Research Institute in Panama.