Other plants, consisting of some ferns, send leaves or shoots that touch the ground and grow roots to sustain a brand-new plant. However the Panamanian tree fern, Cyathea rojasiana, reconfigures its “zombie leaves,” reversing the flow of water to draw nutrients back into the plant. Credit: Graphic by Camila Pizano, color by Michael VincentPlant biologists have discovered that a distinct types of tree fern, unique to Panama, has the ability to regrow its departed leaf fronds into root-like structures. This fern, referred to as Cyathea rojasiana, transforms these “zombie leaves” by altering their water flow direction, enabling them to soak up nutrients back into the main plant.This unusual phenomenon happens only after the leaves droop and die to the ground, stated University of Illinois Urbana-Champaign plant biology teacher James Dalling, who made the discovery with his team while studying a various plant in a Panamanian forest reserve. Dalling seen that the leaves were strongly embedded in the soil and had grown a network of rootlets. Lab tests revealed that the zombie leaves were drawing nitrogen out of the soil.Even after they are converted into roots, the wilted leaves appear like decayed plant matter, which is probably why generations of plant biologists failed to see that they were performing a life-sustaining task, Dalling stated.”This is a truly novel repurposing of tissue. And its unique from what we understand other ferns do,” he said.The Uniqueness of Cyathea rojasianaOther plants, including some ferns, send out shoots or leaves that touch the ground and grow roots to sustain a new plant, he stated. Reconfiguring dead tissue to feed the original plant has actually never ever been reported. The brand-new findings are detailed in the journal Ecology.C. rojasiana comes from an ancient family tree of tree ferns dating back to the Jurassic duration, Dalling said. The zombie leaves are more than likely an adaptation to the nutrient-poor volcanic soils.Geological and Environmental Context”Panama is a land bridge in between North and South America that coalesced 7 million years ago out of an island chain of islands, and those islands are the outcome of volcanic activity in the past,” he stated. “In one website we found, a layer of ashes numerous meters deep looks like sand that you would collect on a sandy beach. The plants that grow there stand out from those that we find elsewhere in that forest reserve.”University of Illinois Urbana-Champaign plant biology professor James Dalling and his associates found that some tree ferns recycle their dead fronds into roots. The scientists call these repurposed leaves “zombie leaves.” Credit: Fred ZwickyThe patchiness of the plant life indicates soil nutrients likewise are unevenly distributed.”And so the tree ferns seem to be putting out arms to sample the surrounding soils,” Dalling said. “Theyre able to sample a higher variety of nutrient environments for the same quantity of investment of rootlets than if they just sent a single rooting structure all around the fern. I think its all about the economics of how they utilize resources in an irregular environment.”The tree ferns likewise grow very slowly.”Theyre most likely placing on one or 2 leaves a year, therefore theyre adding on the order of a few centimeters of height a year,” Dalling said.This indicates each leaf is a major investment of resources that the plant repurposes after the leaf passes away. The sluggish growth likewise suggests that the tree fern is short enough that when its leaves die, they droop all the method to the ground. The trees reach an optimum height of about 2 meters, Dalling said.The finding is “another example of the extraordinary variety of plant adjustments 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 likewise is a research partner at the Smithsonian Tropical Research Institute in Panama.
Other plants, consisting of some ferns, send out leaves or shoots that touch the ground and sprout roots to sustain a brand-new plant. Lab tests exposed that the zombie leaves were drawing nitrogen out of the soil.Even after they are transformed into roots, the wilted leaves look like decayed plant matter, which is probably why generations of plant biologists failed to see that they were performing a life-sustaining job, Dalling stated. And its distinct from what we understand other ferns do,” he said.The Uniqueness of Cyathea rojasianaOther plants, including some ferns, send out shoots or leaves that touch the ground and grow roots to sustain a new plant, he stated. The trees reach a maximum height of about two meters, Dalling said.The finding is “another example of the amazing variety of plant adjustments 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 likewise is a research study associate at the Smithsonian Tropical Research Institute in Panama.