NASA predicts that all of the Florida Keys’ islands and their species will be swallowed by the ocean this century as climate change raises sea levels around the world.
And now, scientists and academics in the Sunshine State have confirmed the first local species driven to extinction by rising hurricanes and sea levels.
The Key Largo tree cactus (Pilosocereus millspaughii) was devoured by local animals desperate for food and fresh water amid increasingly arid and salt-saturated soil.
But since 2015, researchers have struggled to identify the culprits behind the devastation of the thirsty cacti — setting up months of wildlife camera surveillance and studying mysterious tooth marks on more than half of the now-extinct plant species for their new study.
Florida scientists have confirmed the first local species to become extinct due to rising hurricanes and sea levels: the Key Largo cactus. Pilosocereus millspaughiieaten by dehydrated predators (on top of the tufts of long, woolly hairs that grow on the cactus)
The telltale tooth marks and the stripping of the plant of its precious freshwater reserves extended up to four feet above the ground in some cases (as shown in the image above).
“We first noticed a big problem in 2015,” said research botanist James Lange, who worked on the new study, “when we saw saltwater flooding due to high tides in the area.”
Ocean surges in the Keys due to rising sea levels and monster Category 5 storms like Hurricane Beryl “limit the amount of fresh water available to small mammals,” the botanist said, “and could be related to why herbivores targeted this cactus.”
Lange, who works as a field biologist in Miami Fairchild Tropical Botanic GardenHe cautioned that he and his research colleagues “cannot say for sure” exactly what spurred the new wild and aggressive predation on these cacti.
“We’ve never seen so much cactus herbivory in the Lower Keys,” Lange said, “where flooding tends to be less extensive.”
And what thirsty species has been craving the water resources of Key Largo’s cacti also turned out to be a mystery, despite months of camera-trap surveillance.
Researchers, in partnership with Florida’s state-level conservation agencies, installed the cameras in 2016 after discovering in 2015 that about half of the Key Largo cacti they identified had been “gnawed down to vascular tissue.”
The telltale teeth marks and the stripping of the plant of its precious freshwater reserves extended up to four feet above the ground in some cases.
Recent damage from thirsty animals fragmented the cacti (left), and despite visible tooth marks on these now-extinct Key Largo cacti, the exact animal species that accelerated the plant’s extinction managed to elude five entire months of wildlife camera traps in 2016.
Ocean surges in the Keys from rising sea levels and monster Category 5 storms like Hurricane Beryl (above) “limit the amount of freshwater available to small mammals,” said botanist James Lange, “and may be related to why herbivores targeted this cactus.”
‘Of a total of 243 visits captured on camera, raccoons were the most abundant (58 percent), followed by birds (31 percent), marsh rabbits (5 percent), opossums (4 percent) and cotton voles (Journal of the Botanical Research Institute of Texas on Tuesday.
“The camera traps were unable to capture any animal that directly impacted the cacti,” he said.
And yet, by the following year, in 2017, this predatory behavior on cacti had only expanded, killing “About another 50 percent of the population,” he wrote.
Lange and his colleagues at Fairchild worked with the Florida Department of Environmental Protection to take cuttings from the surviving Key Largo cacti in an effort to nurse as many as possible back to health in greenhouses.
But the failed effort means that many unique and beautiful features of this rare species will probably never be seen in the wild again.
Above, an image of the towering Key Largo cactus in healthier, happier times.
“The climate emergency,” according to a statement from the Florida Museum of Natural History, which collaborated on the new study, “has wiped out the naturally growing Key Largo cactus in the United States due to saltwater flooding and soil depletion from hurricanes.”
“The most striking difference is the tuft of long, woolly hairs at the base of the flowers and fruits,” said Alan Franck, current collection manager of the Florida Museum of Natural History’s herbarium, which has a collection of Key Largo tuft specimens.
The cactus’s hair is so thick that during flowering periods it can give the appearance of being covered in snow.
But dehydrated animal predators were only one of the factors that accelerated the cactus’ demise, according to the new study.
Nearly every acre of the islands that make up the Florida Keys (90 percent) sits just five feet above sea level, and the entire island chain is at risk of disappearing by 2100, researchers say.
The increasing saltwater content in the soil and the strong hurricane-force winds that uproot the cacti have already caused a lot of damage to the local ecosystem and to these cacti in particular.
Surveys of the soil salt level surrounding dying cacti began annually in 2007, and an earlier study led by Fairchild Botanical Gardens found that salt levels were higher in the soil beneath Key Largo’s dying cacti.
“The climate emergency,” according to a statement from the University of Florida Museum of Natural History, which collaborated on the new study, “has wiped out the naturally growing Key Largo cactus in the United States due to saltwater flooding and soil depletion caused by hurricanes.”
