🖊️ By Bassam Al Kantar
Head of Campaign Strategy & Communications
🌿 Society for the Protection of Nature in Lebanon (SPNL)
For years, Lebanon’s exceptional biodiversity—compressed into a sliver of land wedged between the Mediterranean Sea and the Syrian Desert—was admired but poorly understood. That is, until a team of Lebanese and international researchers decided to ask a simple yet profound question: What biogeographical region does Lebanon truly belong to?
The answer, as it turns out, is more nuanced than anyone imagined.
In a groundbreaking study published in March 2025 in the journal Ecology and Evolution, ecologists Jean Stephan, Youmna Hammoud, Melissa Korban, and Ignacio Ferro peeled back the ecological layers of Lebanon using cutting-edge ecological niche modeling and species distribution analysis. Their goal? To create the first detailed biogeographic map of Lebanon based on the distribution of native trees and shrubs.
A Nation at the Crossroads of Continents
Lebanon is a mosaic. It’s one of those rare places where four major biogeographic regions—Mediterranean, Euro-Siberian, Irano-Turanian, and Saharo-Arabian—intersect. This unique position, nestled at the crossroads of Asia, Europe, and Africa, means that Lebanon is not just rich in species but also in overlapping ecological identities. However, until now, no one had definitively mapped where one zone ends and another begins—or where they blur into transitional zones.
Trees Tell the Tale
To uncover Lebanon’s biogeographic DNA, the researchers turned to trees and shrubs—what botanists call phanerophytes. These species, with their deep evolutionary histories and clear distribution limits, serve as reliable indicators of ecological regions.
Using 60 native tree and shrub species, and thousands of field observations combined with ecological niche modeling software (MaxEnt), the team simulated each species’ potential geographic range within Lebanon. These were grouped into “chorotypes”—species with overlapping global or local distribution patterns.
The result: nine global chorotypes and five regional ones that, together, paint a stunning new picture of Lebanon’s ecological geography.
The Green Divide
According to the study, the western slopes of Mount Lebanon are a hotspot for Mediterranean and East Mediterranean species—lush, rich, and full of floral diversity. This belt includes species like Cedrus libani (Lebanon cedar), Pinus pinea (stone pine), and Quercus calliprinos (Palestine oak).
But climb higher, and a shift begins.
At elevations above 1400 meters, the Euro-Siberian flora takes root—cool-adapted species like Sorbus torminalis and Ostrya carpinifolia. Go further east, beyond the Beqaa Valley and up the slopes of the Anti-Lebanon mountains, and a drier, starker Irano-Turanian biome emerges. Here, hardy species like Amygdalus orientalis and Prunus korshinskyi dominate.
Even the Saharo-Arabian region makes a cameo—with Pistacia atlantica clinging to the arid southern lowlands and Searsia tripartita narrowly hugging the coast.
In other words, Lebanon is split into two main ecological bodies—Mediterranean west, Irano-Turanian east—intertwined by mountainous transitional zones that host rare endemic trees and serve as evolutionary frontiers.
Zones of Transition: Where Nature Blends
One of the study’s most compelling findings is the identification of biogeographic transition zones—areas where species from different ecological regions mingle.
Most people imagine borders between ecosystems as hard lines. But they’re often fuzzy gradients. What we’re seeing here are ecological melting pots.
These zones are found at high altitudes, on the eastern slopes of Mount Lebanon, and in the southern Anti-Lebanon range—places where Mediterranean species fade and Irano-Turanian flora begin to assert themselves.
Fascinatingly, these very transition areas are also home to Lebanon’s endemic trees—species found nowhere else on Earth, like Quercus look, Pyrus bovei, and Quercus kotschyana. Their presence underscores the importance of these zones for conservation.
A Map with Consequences
For Lebanon, a country under mounting pressure from urban sprawl, climate change, and political instability, this biogeographic map is more than just an academic exercise—it’s a vital tool for conservation.
By understanding where distinct ecological regions lie, and where transitions occur, conservationists can prioritize areas for protection and restoration. The study also provides a blueprint for policymakers to integrate ecological considerations into land-use planning, especially in fragile mountain zones.
Moreover, it sets a precedent for neighboring Levant countries, whose biogeographic boundaries are similarly complex yet largely unmapped.
A Leap Forward in Eastern Mediterranean Ecology
This is the first time Lebanon’s biogeographic structure has been quantified and visualized with this level of precision. We hope it sets a new standard for how biodiversity is studied and managed in the Middle East.
Backed by rigorous modeling and rooted in field data, the study brings clarity to a landscape long shrouded in ecological ambiguity.
And while the team received no formal funding, their collaboration—bolstered by open-source tools and a shared passion for Lebanon’s natural heritage—proves that high-impact science can still thrive in challenging contexts.
Looking Ahead
With more than 60 tree and shrub species mapped and categorized, and the country’s ecological zones finally charted, the path is now open for further research. Could the same methods be applied to herbaceous plants? Animals? Fungi? We need to keep digging—literally and figuratively. Lebanon still has many secrets to tell. And now we have a map to help us find them.
