The Key Largo tree cactus has been officially recognized as the first local species in Florida to be wiped out by rising sea levels. This alarming event highlights the impact of the climate crisis on local biodiversity. Researchers from the Florida Museum of Natural History and Miami’s Fairchild Tropical Botanic Garden have confirmed that saltwater inundation and soil depletion, exacerbated by hurricanes, have eradicated this species from its natural habitat in the U.S.
The Key Largo Tree Cactus’ Disappearing Act: Survival and Relocation
Once thriving in the Florida Keys, the Key Largo tree cactus now survives only on a few remote Caribbean islands, northern Cuba, and parts of the Bahamas. In Florida, the species was reduced to a mere six stems, which were relocated to a greenhouse in 2021 for preservation. Despite efforts and discussions of a potential replanting project with the Florida Department of Environmental Protection (DEP), no naturally growing Key Largo cactuses have been found since.
Rising Sea Levels and the Threat to Florida’s Coastal Plants
The Florida Keys, with 90% of its land at an elevation of 5 feet or less, face severe risks from rising sea levels. NASA predicts a rise of up to 7 feet by 2100, threatening many low-lying coastal plants. Fairchild botanist Jennifer Possley, lead author of a study published in the Botanical Research Institute of Texas journal, noted that the Key Largo tree cactus may be a precursor to how other coastal flora will respond to climate change.
A History of Decline: The Impact of Environmental Changes
The species’ decline was first noticed in 1992 when it was distinguished from the similar Key Tree cactus. A storm surge in 2005 linked increased water salinity to cactus mortality, further exacerbated by hurricanes and high tides that eroded the soil where these cactuses grew. Additionally, mammals in search of fresh water were damaging the plants.
The Final Blow: Natural Disasters and Human Intervention
By 2011, saltwater flooding from king tides became more common, with salt-tolerant plants encroaching on the cactus habitat, indicating rising salt levels. By 2017, Hurricane Irma and subsequent king tides further devastated the cactus population, leading to the decision to relocate the remaining stems.
Lessons Learned: The Key Largo Tree Cactus as a Climate Change Indicator
The study’s authors, including experts from the DEP and the University of Florida, stress that the Key Largo tree cactus’s extinction provides crucial insights into the future of other species as climate change progresses. However, James Lange, a research botanist at Fairchild, emphasizes that mitigating such environmental damage requires a comprehensive, multi-disciplinary conservation approach.
