Alliance for Zero Extinction (AZE) sites are the last remaining refuge of one or more Endangered or Critically Endangered species. They are therefore of vital conservation importance.

BGCI has developed a methodology for identifying potential Alliance for Zero Extinction (AZE) trigger species using IUCN Red List data. Each year we update the potential AZE species list using the methodology with the latest IUCN Red List update.

Using the more recent IUCN Red List update (2026-1) we have now identified 4,128 potential AZE tree species across 120 countries. The 10 countries with the most potential AZE tree species are:

Madagascar – 473 species
Philippines – 410 species
Brazil – 249 species
Indonesia – 235 species
Papua New Guinea – 232 species
Mexico – 201 species
Colombia – 147 species
Malaysia – 147 species
Peru – 125 species
United States – 106 species

All confirmed AZE sites also qualify as Key Biodiversity Areas (KBAs) under KBA criterion A1e. BGCI is now working on incorporating these potential AZE species into the KBA database as trigger species. More information can be found here: https://www.bgci.org/our-work/projects-and-case-studies/alliance-for-zero-extinction-tree-species/