Treedom Blog: Sustainable & Green Lifestyle

How Many Tree Species Are There? A Global and European Forest Perspective Summary

Written by Tommaso Ciuffoletti | Dec 23, 2025 10:50:59 AM

Trees are the silent giants of the land — essential to life on Earth, yet astonishingly under-charted. Recent scientific research suggests the planet is home to an estimated 73,000 tree species, yet about 9,000 remain undiscovered or formally undescribed by science. Many of the species we already know are under threat, caught in the crosshairs of habitat loss, climate change, and invasive species. This article explores the latest knowledge on global tree diversity, species at risk, and then shifts focus to the European Union’s forests - their extent, condition, origins, and role in the global forest landscape. By linking global data and EU statistics, we paint a clearer picture of where forests stand today and why they matter more than ever.

How Many Tree Species Are There in the World?

Understanding the total number of tree species on Earth has long been a challenge for botanists. A groundbreaking study published in Proceedings of the National Academy of Sciences (PNAS) used an innovative statistical approach based on over 44 million tree records from more than 100,000 forest plots worldwide. The result: scientists estimate about 73,000 tree species on Earth -significantly more than earlier approximations.

This figure reflects the best data available to date, combining field inventories with modeling techniques to estimate diversity even in poorly explored regions. Importantly, it acknowledges that current taxonomic knowledge is still incomplete.

How Many Tree Species Are Still to Be Discovered?

The same research highlights a striking fact: roughly 9,000 tree species - more than 12 % of the total - are still unknown to science or not yet formally described.

These undiscovered species are likely to be highly localized and rare, particularly in tropical and subtropical regions such as the Amazon basin. Their scarcity and limited ranges make them especially vulnerable to extinction before they are even documented.

Tree Species at Risk of Extinction

While the number of known tree species is growing, so too is awareness of their vulnerability. According to the IUCN Red List of Threatened Species, a significant portion of known tree species are classified as threatened (Vulnerable, Endangered, or Critically Endangered). Recent assessments presented at global biodiversity forums indicate over one-third of tree species face extinction risk, driven by habitat loss, land-use change, climate impacts, and invasive species pressures. 

The degradation and conversion of natural habitats - particularly in tropical forests - remain the leading drivers of species loss. Even as some regions regain tree cover through reforestation, this does not necessarily equate to recovery of original biodiversity.

African, Asian, and South American Tree Diversity - A Snapshot

Globally, tropical regions host the greatest diversity of trees. South America, Africa, and Southeast Asia are home to thousands of species, many of which occur only in specific habitats. These regions also face high deforestation rates due to agricultural expansion, logging, and infrastructure development. While the rate of natural forest loss has slowed in some areas, the magnitude of historical loss and ongoing pressures still pose urgent conservation challenges.

Forests in the European Union: Extent and Trends

The European Union (EU) has a very different forest dynamic from the tropics or boreal regions. According to Eurostat and EU forestry statistics, as of 2022 the EU had approximately 160 million hectares of forests - covering roughly 39 % of the EU’s land area.

Unlike many parts of the world where forest cover is declining, forests in the EU have been steadily increasing over the past decades. Since 1990, the EU’s forest area has grown by several million hectares, thanks to both natural expansion on abandoned agricultural land and active afforestation efforts.

However, this growth masks important differences in forest condition and origin.

Primary, Semi-Natural, and Planted Forests in the EU

A key question for the European forest landscape is how much of it is genuinely natural versus shaped by human activity. Most forests in the EU are the result of centuries of land use, management, and reforestation. According to European Environment Agency assessments:

  • More than 90 % of EU forest area is semi-natural, meaning it has been influenced by human management but still retains natural characteristics.

  • Plantations - forests deliberately planted, often with a limited number of species - account for about 3 % of total forest area.

  • Primary and old-growth forests - those with minimal or no significant human disturbance - represent less than 4 % of EU forest cover.

These figures illustrate that true old-growth forests within the EU are rare and fragmented, making their protection critical for biodiversity conservation.

Forest Management and Biodiversity Implications

The prevalence of semi-natural and managed forests in Europe influences not just forest structure but biodiversity. Many forest stands are even-aged and composed of only a few tree species, partly due to historical forestry practices focused on productivity.

This can make forests more vulnerable to disturbances such as drought, pests, and fires, especially under changing climate conditions. Increasing species diversity and restoring natural structures where possible are priorities in European forest strategies.

EU’s Role in Combating Global Deforestation

While the EU’s internal forest area is increasing, European consumption and trade have historically contributed to deforestation abroad. Studies suggest that EU demand for commodities such as soy, palm oil, and beef has non-trivial links to deforestation in tropical forests, making up a notable share of global deforestation associated with trade.

To address this, the EU has developed the EU Deforestation Regulation (EUDR) - legislation aimed at ensuring that certain commodities imported into the EU are not associated with recent deforestation. Implementation timelines have evolved, but the law represents a major step in linking EU consumption to global forest protection.

Why the EU Forest Situation Matters Globally

European forests play a substantial role in carbon sequestration, biodiversity conservation, and regional climate regulation. EU forests are estimated to absorb around 10 % of the Union’s greenhouse gas emissions annually, a significant contribution to climate mitigation efforts.

Yet the distinction between natural and managed forest underscores the need for strategies that balance ecological integrity with economic use. Protecting rare old-growth areas, enhancing species composition, and maintaining resilient ecosystems are central to future forest policies.

Conclusion

Trees remain one of the most essential yet under-appreciated components of the Earth’s biosphere. With an estimated 73,000 tree species on Earth - and nearly 9,000 still to be discovered - our understanding of forest biodiversity continues to evolve. Many of these species face threats from human-driven habitat change and climate impacts.

The European Union, while geographically distant from tropical deforestation hotspots, is a major forested region in its own right, with forests covering close to 40 % of its land area and continuing to expand. However, the fact that primary forests are only a small fraction of total forest cover highlights the historical influence of human management. EU forests are predominantly semi-natural or managed stands, making forest policy, biodiversity protection, and sustainable management critical priorities.

Whether in the Amazon basin or in the European greenwood, forests remain vital for life on Earth - and our knowledge, stewardship, and policies must continue to evolve to protect them.

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