Key Largo Tree Cactus Goes Extinct in US: Florida’s Rare ‘Pilosocereus millspaughii’ Becomes First Local Species Killed by Rising Sea-Level

Due to the devastating impacts of climate change, the Key Largo tree cactus has been declared extinct in the United States. This rare cactus, which once thrived in the Florida Keys, has become the first local species to be wiped out due to rising sea levels. According to researchers from the Florida Museum of Natural History and Miami’s Fairchild Tropical Botanic Garden, ‘Pilosocereus millspaughii’, which was growing naturally in the US, has been killed through saltwater inundation and soil depletion from hurricanes. The species, now found in the remote Caribbean islands, northern Cuba and areas of the Bahamas, has fallen to only a single population of six stems in the Florida Keys.

In 2021, Key Largo cactuses were removed to a greenhouse to ensure the species' survival. Since then, frequent searches have revealed no instances of natural growth. Besides, there is little prospect of it re-establishing itself despite “tentative plans” with the Florida Department of Environmental Protection (DEP) for a small-scale replanting project. Ultra-Rare Przewalski's Horse Born in Marwell Zoo That Went Extinct in The Wild 40 Years Ago; See Pics of The Foal. 

Around 90 percent of the low-lying Florida Keys island chain is at 5ft of elevation or less, with Nasa predicting future ocean rise of up to 7ft by 2100.

Fairchild botanist Jennifer Possley, lead author of a study in the journal of the Botanical Research Institute of Texas that chronicled the species’ decline, stated, “Unfortunately, the Key Largo tree cactus may be a bellwether for how other low-lying coastal plants will respond to climate change.” Scientists also noticed that the Key Largo tree cactuses were already in poor health in 1992, when it was first discovered to be a separate species to the Key Tree cactus, which is similar in appearance and present elsewhere in the Keys, also declining in numbers. Golden Langur Becomes Extinct After Last Surviving Primate From Assam's Umananda Passes Away. 

A 2005 storm in the lower Keys established a link between water salinity and cactus mortality. Frequent surges from hurricanes and exceptionally high tides eroded the layers of soil and organic matter close to the shore where the Key Largo cactuses were growing. Besides, the researchers found that as mammals were deprived of fresh drinking water elsewhere, they ate the moisture-retaining plants, which caused even more damage.

“In 2011, we started seeing saltwater flooding from king tides in the area,” said study co-author James Lange, a research botanist at Fairchild and member of a team who returned every year to study the health of the cactuses. He added, “We’d never seen cactus herbivory like this anywhere in the lower Keys, where flooding has tended to be less extensive.”

He also mentioned that the salt-tolerant plants that had been earlier restricted to salty soils beneath the mangroves slowly began creeping up the outcrop. This indicated a rise in the salt levels. These conditions would have eventually killed the species, and within a few years, almost 50 percent of the Key Largo cactus population had been lost.

Moreover, category 4 Hurricane Irma swept over south Florida in 2017 and destroyed more cactuses, leaving the area flooded for weeks. This was followed by consecutive king tides in 2019. Two years after that, decisions were made to “evacuate” the small number of stems that still survived.

Inputs from the DEP and researchers from the University of Florida mentioned that the death of the Key Largo tree cactus and the necessity of its removal have given the study's authors a better idea of what to expect as more species are affected by the climate crises.

“Understanding and predicting the fate of rare organisms and their habitats in the face of climate change will likely be complicated by similar ecological interactions and will require a multi-disciplinary approach to conservation,” Lange said.

The extinction of the Key Largo tree cactus in the United States marks a sombre milestone in the ongoing battle against climate change. As the first local species in Florida to succumb to rising sea levels, Key Largo symbolises the broader threat to biodiversity posed by global warming. It is a call to action for increased efforts to combat climate change and protect the natural world from further irreparable loss.

(The above story first appeared on LatestLY on Jul 12, 2024 11:58 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).