Rare Florida tree cactus becomes extinct due to sea level rise in the US, study shows

In a significant development, researchers have reported the first local extinction of a species in the United States due to sea level rise. The Key Largo tree cactus, a rare species restricted to a small population in the Florida Keys, has succumbed to saltwater intrusion, soil erosion, and herbivory by mammals, leading to a drastic decline in numbers. By 2021, only six fragile fragments remained, prompting researchers to relocate them for off-site cultivation to ensure their survival. Jennifer Possley, the director of regional conservation at Fairchild Tropical Botanic Garden, highlighted the implications of this extinction event, suggesting that it could serve as a warning for other coastal plants facing the impacts of climate change. The decline of the Key Largo tree cactus, documented in a study published in the Journal of the Botanical Research Institute of Texas, underscores the challenges faced by low-lying coastal species in the face of environmental threats. The loss of the Key Largo tree cactus is attributed to human-caused climate change, with rising sea levels posing a direct threat to coastal ecosystems. Scientists from the Florida Museum of Natural History and Fairchild Tropical Botanic Garden have taken proactive measures to safeguard the remaining fragments of the species by relocating them to a greenhouse. Despite tentative plans for a small-scale replanting project, the chances of natural re-establishment are slim. The decline of the Key Largo tree cactus can be traced back to events such as storm surges, high tides, and saltwater flooding, which have progressively degraded the habitat of the species. The findings of the study underscore the urgent need for conservation efforts to mitigate the impacts of climate change on vulnerable plant species in coastal regions, emphasizing the complex challenges involved in preserving biodiversity in the face of environmental threats.