Researchers have identified the top threats to the United States’ only population of rare, endangered mule-eared orchids
The Florida International University (FIU) orchid research team found that powerful hurricanes can wipe out these fragile plants, but an invasive species of scale insect that feeds on the leaves is the main cause for concern.
The results were published in ecosphere.
“We observed mule-ear orchids that had scale insects were more likely to die,” said Haydee Borrero, the study’s lead author and FIU postdoctoral fellow. “This is an invasive species that has affected other species of orchids on Florida’s west coast. So we have to be worried.”
Borrero and FIU conservation ecologist Hong Liu have long been guardians of mule-ear orchids. These orchids grow exclusively throughout the Caribbean, with the largest populations scattered over remote regions of Cuba. Their northernmost range is the buttonwood hammocks in South Florida in Everglades National Park.
As part of her Ph.D. While working at the FIU, Borrero traveled to Cuba to conduct field studies to better understand these little-studied orchids and found that those in Cuba lacked the invasive scale insect known to infest the leaves of mule orchids in Florida covered.
As the name suggests, these leaves resemble the large floppy ears of a mule. When this species of scale insect attacks the leaves, it cripples and shrivels the plant. When the team returned to a study site where scale insects had been observed on orchids two years earlier, many of the affected plants were dead.
Losing even a single adult mule-eared orchid can be devastating, Borrero said. That’s one less plant in an already small population to grow the next generation of much-needed orchids and bring them closer to extinction.
“This was a very important and exciting project because we were able to perform an analysis with long-term data to better distinguish which impacts cause more damage,” Liu said. “What we have found is complex. It is not easy. Yes, hurricanes are a threat. But herbivores are a bigger threat.”
In 2017, Hurricane Irma caused its share of damage as a Category 3 storm surge swept across the southern Everglades. While the hurricane damaged the orchid population, it also did major damage to the scale insect population. With fewer insects in the years after Irma, the mule-eared boys went into recovery mode.
Borrero and Liu are monitoring and using this data to develop future management strategies and possible rescue strategies for the endangered orchid.
The healthier Kuba populations are a kind of blueprint because they are also growing in coastal regions that are prone to hurricanes and floods. However, the forests in which they live have a greater diversity of tree species. This important information can provide clues as to which areas of Florida with similar tree species are well suited to relocate and expand Florida’s vulnerable population.
“One of the reasons we did this research was so we could be better informed [conservation] Recommendations – what do the habitats in Cuba look like? And do we have similar habitats in Florida where we could plant and introduce these plants,” Borrero said. “One idea is to look at the Royal Palm Hammock area [within the Everglades National Park]it has [habitat] Traits that match populations [in] Cuba.”
Meanwhile, the FIU’s orchid team refuses to give up Florida’s mule-ear orchids. For Borrero, the mission couldn’t be easier.
“They will die out if we do nothing. If we help them, they will survive.”
Haydee Borrero et al., Populations of a tropical epiphytic orchid are destabilized in their peripheral range by a hurricane and an exotic herbivore, ecosphere (2023). DOI: 10.1002/ecs2.4355
Provided by Florida International University
Citation: Saving Florida’s only population of rare, endangered orchid from extinction (2023, January 25), retrieved January 25, 2023 from https://phys.org/news/2023-01-florida-population-rare-endangered-orchid .html
This document is protected by copyright. Except for fair trade for the purpose of private study or research, no part may be reproduced without written permission. The content is for informational purposes only.