One of the most socioeconomically important plant groups in the world, palms are a keystone family providing essential contributions to millions of people. Global anthropogenic changes pose known threats to the many benefits that Arecaceae provide, but only 23 per cent of the family's species have been assessed for extinction risk recently.
Recognizing the time-consuming and resource-intense process required for gold-standard Red List assessment, this study employed a machine-learning approach to predict extinction risk based on existing assessments, coupled with variables on climate, human impact and forest loss derived from GBIF-mediated occurrences of all palm species.
After training and testing the approach, the authors' most accurate model classified 703 palm species as threatened. When combined with existing assessments, this suggests that 56 per cent of the 1,889 palm species were threatened.
To help set conservation priorities, the authors also explored the extinction risk among species of interest—those that are functionally distinct, genetically distinct or used in some fashion. This analysis assessed around 48 per cent of the functionally and evolutionarily distinct species as threatened, compared with 29 per cent of the species in use.
Based on the total evidence, the researchers identified 25 regions in which more than 40 per cent of palm species of interest were threatened, including Madagascar (82 per cent), New Guinea (58 per cent) and Philippines (57 per cent). Some regions, such as Viet Nam and Vanuatu, presented as novel priority regions for palm conservation.
While the study identified potential use substitutes for 91 per cent of the threatened species, sixteen species lacked substitutes, affecting at least one species in 30 regions. The potential loss of important irreplaceable palm species highlights the urgent need for conservation action.