More than 16,600 sites spanning five continents — from the Congo Basin's rain-soaked canopy to the biologically rich coastlines of Southeast Asia — have been formally identified as Key Biodiversity Areas (KBAs), a scientific designation that carries more weight for the future of life on Earth than almost any acronym in circulation. These areas are much more than nature reserves; they are specifically mapped places where endemic species concentrate in disproportionate numbers and ecological processes underpin clean air, fresh water, and food security.
The International Union for Conservation of Nature (IUCN) defines a KBA as "a site that contributes significantly to the global persistence of biodiversity" — a phrase that may sound bureaucratic but describes something quite urgent: those 16,600-plus mapped sites currently protect vital populations of more than 18,600 species globally. Yet only about 20 percent are fully covered by protected areas. Human activity has driven a 70 percent average decline in habitat size within KBAs due to fragmentation, and the IUCN Red List Index, which identifies threatened and endangered species, shows extinction risk has increased more than 12 percent since 1993.
What Qualifies a Key Biodiversity Area?
The IUCN's Global Standard for the Identification of Key Biodiversity Areas, published in 2016 and co-developed by BirdLife International, the Critical Ecosystem Partnership Fund (CEPF), Conservation International, Re:wild, and the Wildlife Conservation Society, establishes 11 criteria across five categories for designation: threatened biodiversity, geographically restricted biodiversity, ecological integrity, biological processes, and irreplaceability. A site must satisfy at least one to qualify.
This framework transforms biodiversity from something abstract into something quite actionable. KBAs are used by governments in spatial planning, by the financial sector to guide investment away from fragile ecosystems, by corporations assessing supply chain risk, and by NGOs and donors to determine where conservation funding will have the highest impact. The thresholds in the KBA Standard are designed to identify sites that contribute significantly to the global persistence of biodiversity under each of the KBA criteria, according to the IUCN's guidelines — meaning every site on the list earned its place through quantifiable, peer-reviewed evidence.
As of March 2024, 43.4 percent of terrestrial KBAs were covered by some form of protected area designation. Progress varies dramatically by region: Northern America and Europe now show approximately 60 percent mean coverage, while Oceania's land-based KBAs sit at 18.7 percent.
Ecosystem Biodiversity and the Services We Cannot Live Without
Biological diversity extends well beyond the species lists. Ecosystem diversity — the range of different habitats, ecological communities, and biological processes across a landscape — is the mechanism by which nature delivers what economists call ecosystem services, and what everyone else experiences as functioning daily life. Healthy, biodiverse ecosystems provide 75 percent of the world's freshwater resources. Forests that overlap with KBAs absorb approximately 2.6 billion metric tons of carbon dioxide annually. More than 75 percent of global food crops depend on pollinators, many of which rely on biodiverse habitats to survive — contributing between $235 and $577 billion annually to global agricultural output.
When ecosystem biodiversity collapses, the consequences are disastrous. Wetlands — many of which fall within or adjacent to KBAs — have declined by 35 percent globally since 1970. These vital areas are currently vanishing three times faster than forests. That loss reduces water purification capacity and threatens freshwater access for more than 2 billion people. The World Health Organization identifies biodiversity loss as a public health issue, with degraded ecosystems linked to increased disease transmission risk. The total estimated value of ecosystem services globally runs to approximately $125 trillion annually — and the majority of those services flow from precisely the kinds of intact, biodiverse habitats that KBAs represent.
According to Harvey Locke of the IUCN, too often biodiversity is seen as “a ‘nice-to-have’ luxury that takes second place to so-called ‘real world’ concerns about the economy and human development.”
Locke co-authored a recent study published in the journal Frontiers. The authors concluded that human activities are driving a global decline in biodiversity, which are “interfering with the natural processes essential for human well-being.” They suggest that achieving global climate and development goals is “impossible without keeping nature intact.”
Biodiversity Hotspots Hold Half the World's Species
The relationship between KBAs and biodiversity hotspots is one of scale. Biodiversity hotspots — a concept developed by Conservation International based on two strict criteria: a region must contain at least 1,500 endemic vascular plant species and must have lost at least 70 percent of its primary vegetation — represent the most extreme concentrations of biological diversity on the planet. There are 36 recognized hotspots worldwide. Their intact habitats cover just 2.5 percent of Earth's land surface, yet they support more than half of the world's plant species as endemics and nearly 43 percent of bird, mammal, reptile, and amphibian species as endemics.
Leonardo DiCaprio’s foundation, Re:wild, one of the core supporters behind the KBA Partnership, prioritizes conservation work within these ecological hotspots and has mapped more than 16,000 KBAs on land and in the sea, covering important populations of more than 13,100 species. Its position is that KBAs provide "a blueprint for most effectively conserving and scaling up action for our planet's biodiversity." The reasoning is straightforward and numerically defensible: protecting a small percentage of the Earth's surface in the right places yields conservation outcomes that would be impossible to replicate across the broader landscape.
Last year, Re:wild purchased an island off the coast of Chile to end deforestation on the island, which is home to rare species including the sooty shearwater seabirds. “The irreplaceable Island of Guafo is now protected from coal mining, logging, and other destructive industries,” DiCaprio said in a statement.
Turning Key Biodiversity Area Science Into Ground-Level Action
One Tree Planted takes that blueprint into active practice. We work directly within and adjacent to biodiversity hotspots and KBAs to rebuild what fragmentation and deforestation have stripped away, like our work in Uganda's Albertine Rift — a recognized biodiversity hotspot that ranks first among continental Africa's 119 terrestrial eco-regions for number of endemic species and is home to over 50 percent of the continent's bird species and 39 percent of its mammals. This project demonstrates the impact that’s possible when restoration targets the right places with the right species.
Healthy forests shelter 80 percent of all amphibian species, 75 percent of all bird species, and 68 percent of all mammal species on land. Within KBAs and ecological hotspots, reforestation is rebuilding the specific layered habitat structure that endemic and threatened species require to survive.
Designating a KBA is a scientific act. Restoring one is a physical and sustained commitment — it’s where One Tree Planted's work is directly relevant to the biodiversity crisis. We target landscapes identified as having the greatest ecological need, including areas with significant land degradation, climate-critical regions, and key biodiversity corridors. Planting trees restores critical habitat for these species, some of which can be found nowhere else on earth.
Across Africa specifically, One Tree Planted is a core partner in TerraFund for AFR100, a landscape restoration initiative managed alongside the World Resources Institute and Realize Impact that channels financing directly to locally led projects across the continent. Our work is explicitly framed around ecosystem connectivity — restoring not just individual stands of trees but the functional links between them that allow wildlife to move, populations to intermix, and biodiversity to persist at scale.
The geographic range of that commitment spans several of the world's most pressured ecological hotspots. In Latin America, One Tree Planted operates in and around the Tropical Andes — the single most species-diverse region on the planet, containing one-sixth of all plant species on Earth — as well as across the Amazon and Central American biodiversity corridors. In Asia, its projects are restoring habitat for critically endangered species. The through-line across all of it is the same principle that underpins the KBA framework itself: where you restore matters as much as how much you restore.
“We must act now to halt and reverse the loss of nature by 2030 toward achieving an integrated equitable, Nature Positive, and carbon neutral future,” Locke says.
Since 2014, One Tree Planted has planted more than 171 million trees across 84 countries working with 489 partners, making us one of the most operationally active reforestation organizations working at the intersection of community needs and ecological urgency.
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