Not All Forests Are Equal: Why Primary Forests Are Irreplaceable

So, What’s the Difference Between Forest Types?

Let’s break it down. Not all forests are created equal, and understanding these differences is key to protecting them.

• Primary Forests: The Last Intact Forest Ecosystems
  • Primary forests are among the most important ecosystems on Earth. These forests have evolved over centuries, with natural processes taking the lead and having faced limited negative anthropogenic disturbances. They store the most carbon, house incredibly diverse species (many of which are found nowhere else), and provide services essential for societal wellbeing, like water purification, flood prevention, and even disease regulation. Once lost, primary forests cannot be fully restored within a reasonable timeframe - if ever.
     
• Secondary Forests: Rebuilding, but Not the Same
  • Secondary forests are areas that regenerate after the original forest has been disturbed or cleared by human activities like logging or agriculture. While forests can regenerate, the intricate biodiversity and ecological functions of primary forests are the result of centuries - often millennia - of undisturbed growth, making them virtually irreplaceable. They may hold carbon, and much of the biodiversity may return, but it’s often an echo of what was once there. Restoration efforts can certainly help regain ecological integrity, especially when evidence-based forest landscape restoration (FLR) is implemented, but secondary forests are more vulnerable to future disruption and do not offer all of the same benefits as primary forests.
     
• Plantation Forests: Designed for Timber, Not Conservation
  • Plantations are intentionally planted forests, often to meet timber, paper, or other commodity needs. They are typically monocultures - meaning they’re composed of one or two tree species - and they lack the biodiversity of natural forests. While plantations have a role in meeting many social and economic needs, they aren’t a substitute for protecting natural forests, nor are they the only models capable of meeting production needs. They store less carbon and provide fewer benefits for wildlife and people. So while these landscapes can be economically important, they shouldn’t be seen as replacements for conservation of natural, intact forest landscapes (IFLs), like primary forests.

Why Primary Forests Are Irreplaceable

What makes primary forests so special? Primary forests are essential for a host of reasons, including:

• Unmatched Carbon Storage & Climate Regulation
  • Primary forests store more carbon than any other type of forest. The deep roots of old-growth trees and the stability of undisturbed soils lock away vast amounts of carbon that would otherwise be released into the atmosphere. When these forests are logged or destroyed, that stored carbon is unleashed, intensifying the climate crisis. Restored forests can take centuries to reach the same carbon storage levels. Therefore, it’s essential to protect what’s already in place.
     
• Biodiversity That Can’t Be Recreated
  • Many species are uniquely adapted to life in primary forests and simply can’t survive in secondary forests or plantations. These ecosystems support biodiversity that can’t be found anywhere else - endemic and threatened species that are often critical for maintaining ecosystem balance and resilience. If we lose these primary forests, we lose critical habitat and endangered species, as well as the potential for life-saving medicinal discoveries and a huge chunk of the planet’s genetic diversity.
     
• Essential for Human Health
  • Primary forests also play a critical role in protecting human health. For example, they filter water, provide forest foods, help regulate the spread of diseases, and even protect against floods and natural disasters. They act as natural barriers against disease transmission within plant and animal populations and shield people from being exposed to dangerous zoonotic diseases. Losing primary forests could mean more frequent floods, droughts, loss of food and water security, and a higher risk of new diseases jumping from animals to humans.
• Essential for Indigenous and Local Communities
  • Primary forests are often found in or near Indigenous lands, where they have been sustainably managed for generations. These forests provide food, medicine, and cultural value to Indigenous communities. Protecting these forests is not only about preserving ecosystems - it’s about safeguarding the rights and livelihoods of Indigenous peoples and local communities. Over 80% of the Earth’s terrestrial biodiversity exists in forests, many of which are Indigenous-managed primary forests. These communities are the best stewards of their homes, and supporting their conservation efforts is both an environmental and human rights imperative.

Shifting the Focus: Prioritizing Conservation

Here’s the thing: The most effective, cost-efficient, and ecologically sound approach to conservation is preventing the loss of our existing primary forests. Restoring secondary forests is essential for reforestation efforts and must be employed in degraded and deforested areas for the sake of people, biodiversity, and climate. However, it cannot be our only tool for fighting the climate crisis. Rather, restoration should complement conservation efforts by improving ecological functionality and integrity in already degraded areas, or by diverting pressure from intact ecosystems. For example, restoration can improve buffer zones around primary forests, increase connectivity between primary forest patches, or make degraded land productive once more to halt the need for further deforestation. In this way, restoration and conservation efforts can work together to support nature and allow us to protect the remaining, old-growth forest ecosystems that are still intact.

Protecting What Matters Most

So, what can we do? First, we need to clearly differentiate how plantation forests, secondary forests, and primary forests support people, biodiversity, and climate resilience. Then, policy frameworks must better acknowledge and reflect these differences. Let’s be clear: while restoring degraded and deforested areas is extremely important, it is not a substitute for keeping intact, primary forests standing. And we must do more to fund Indigenous and local-led conservation efforts - because they are the guardians of these natural sanctuaries and have been for centuries.

As we approach critical global policy discussions, such as the 20th session of the United Nations Forum on Forests (UNFF20) and the 2025 UN Climate Change Conference (UNFCCC COP 30) later this year, world leaders have the opportunity to recognize just how valuable these ecosystems are.

One of the most effective strategies for climate action and biodiversity conservation is straightforward: protect primary forests where carbon is stored, biodiversity thrives, and human health is safeguarded. Put plainly, healthy forests mean a healthy world.