small forest clearings, big impact

ABSTRACT

Small persistent clearings in tropical forests cause significant forest biomass loss

The latest research published in Nature shows that even small clearings and forest fragmentation can cause much higher carbon and biodiversity losses than previously expected, altering the microclimate and weakening the entire ecosystem. It is not only the quantity of forest lost that matters, but its integrity. The approach of Foreste per Sempre OdV, based on restoring areas degraded by grazing, fires, and logging, proves particularly effective: stitching together these “voids” means strengthening the forest’s resilience and its role in fighting climate change. In Costa Rica, in the Karen Mogensen Reserve, this commitment translates into concrete actions of regeneration and protection. Supporting the acquisition of new areas to restore is now a fundamental step to expand this positive impact.

Small clearings that cause big damage, the invisible wounds accelerating the forest crisis: what science tells us and why our work is even more urgent.

When thinking about tropical deforestation, the collective imagination evokes large-scale logging operations, vast bare plains where ancient forests once stood, landscapes transformed in a few months. Satellite images of agricultural frontiers devouring square kilometers of virgin forest. Yet science reveals a subtler and, in some ways, even more worrying story. A study just published in Nature by an international team of researchers sheds new light on an often-overlooked phenomenon: small persistent clearings, those that nobody notices in the newspapers, but which are silently eroding the planet’s forest heritage. Even small clearings, seemingly marginal fragments of degraded or converted forest, have a much larger impact than previously thought.

The study, led by Yidi Xu and colleagues, analyzed the dynamics of carbon stored in tropical humid forests between 1990 and 2020. The finding is striking: tropical humid forests have lost a total of approximately 15.6 billion tons of carbon in above-ground biomass — a massive net loss, driven primarily by small persistent deforestation clearings. Although small deforestation clearings (those smaller than 2 hectares, often linked to small-scale farming or extensive grazing) account for only 5% of the total disturbed area, they are responsible for over half (56%) of carbon losses. Why such a disproportionate impact? Unlike natural fires or selective logging, after which the forest has some capacity to regenerate, these small clearings tend to be kept open over time. The soil is converted to pasture or cropland, permanently preventing the forest from returning, along with the restoration of its precious carbon stock and biodiversity.

In practice, a myriad of small cuts, almost invisible when observed individually, add up to cause a carbon hemorrhage and destroy vital habitats with far greater effectiveness than a single large deforestation event. Moreover, the study highlights that over time deforestation has shifted towards forests with increasingly higher carbon density, further worsening the balance. This is a wake-up call that redraws priorities: protecting the forest also means, above all, caring for these seemingly minor wounds.

It is a paradox that invites reflection. The enemy of forests is not only large-scale industrial deforestation: it is also — perhaps above all — fine-grained fragmentation, the small clearing to make room for a few head of cattle, the fire set to renew pasture, the selective logging that leaves an open wound in the dense woodland. These small voids, often caused by grazing, fires, or selective logging, do not merely remove a portion of forest cover. They profoundly alter the functioning of the surrounding ecosystem. Forest edges become more exposed to wind, light, and temperature variation, modifying the microclimate and accelerating the loss of carbon stored in soil and biomass. At the same time, many animal and plant species, particularly sensitive to the forest’s interior conditions, disappear or are drastically reduced. Small wounds, almost invisible from above, that multiply and never heal, turning into loss of carbon, biodiversity, and climate resilience.

This is where Foreste per Sempre OdV’s on-the-ground action becomes not just relevant, but truly impactful. Our projects for years have been aimed precisely at restoring these degraded areas, which science tells us are the critical knot of the climate crisis and biodiversity loss. We do not work on vast monocultures or large industrial estates: we immerse ourselves in the fragmented fabric of forests, those that have suffered from overgrazing, small arson fires, or selective logging.

Our commitment in Costa Rica is an emblematic example. Here, on the Nicoya Peninsula, one of the most biodiverse areas on the planet, we are regenerating precisely those small clearings that the Nature study identifies as a priority. These are areas that from the outside may still look like “a bit of green,” but which have actually lost their ecological structure, species diversity, ability to store carbon, and to withstand climate stresses. Our projects involve acquiring degraded land parcels, often former pastures, and letting them undergo assisted natural regeneration, planting native species when necessary. Within a few years, we see life returning: trees regrowing, capturing carbon at a surprising rate, and with them animals, from the collared peccary to the puma, finding reconnected ecological corridors. Every small plot we restore is not an isolated point, but a tile that recomposes a vital mosaic, precisely where the damage is most insidious but also most reversible.

This is exactly the territory where Foreste per Sempre OdV operates with its Partners.

The projects we carry out, in Costa Rica as in other intervention areas, are not aimed at large intact forests — those, fortunately, already enjoy a certain amount of international attention. Our focus is on degraded areas, which scientific research now indicates as the Achilles’ heel of the system: areas eaten away by abusive grazing, crossed by repeated fires, emptied by selective logging. These are areas that from the outside may still look like “a bit of green,” but which have actually lost their ecological structure, species diversity, ability to store carbon, and to withstand climate stresses.

In Costa Rica, where we are present with some of our most mature initiatives, this type of degradation is particularly widespread in the border territories between protected reserves and private agricultural lands. The pressure of extensive grazing and seasonal fires has left entire forest strips in a state of chronic degradation: tree cover exists, but it is discontinuous, impoverished, unable to fully perform its ecological functions. These are exactly the “small persistent clearings” mentioned in the Nature study: not total absences of forest, but recurrent voids that prevent regeneration and amplify carbon and biodiversity losses disproportionately to their extent. Science confirms that these recovering forests, if protected and allowed to grow, can become an extraordinarily valuable carbon sink and biodiversity reservoir. Every restored hectare is not only valuable in itself: it breaks the isolation of clearings, reduces edge effects, and allows the surrounding forest to breathe better.

Science tells us that intervening in these small areas has a more-than-proportional effect. And we still have the opportunity to do so. Right now, we can take a decisive step to purchase an additional portion of degraded forest to be annexed to the Karen Reserve in Costa Rica, acquiring a further portion of degraded forest for regeneration, thanks to the commitment of our partner Asepaleco. This is an area that perfectly matches the profile described by the research: land already partially forested but marked by decades of human pressure, with persistent clearings that prevent spontaneous recovery and rob the forest — and the climate — of enormous potential. These are adjacent lands, currently used as pasture, which once regenerated would become a fundamental biological corridor and an active carbon sink.

To do this, we need your help. A donation to Foreste per Sempre does not fund an abstract project: it funds the purchase of real land, the protection of concrete ecosystems, the closing of those small open wounds that science tells us weigh heavily on the future of our planet. Every contribution, large or small, translates into hectares taken from degradation and returned to life.

You can donate on our website and directly participate in the expansion of the Karen Reserve. Because sometimes, as this research teaches us, it is precisely the small actions — the small clearings closed, the small forests protected — that make the biggest difference. 🤝 Donate now. ✨

Scientific source: Xu et al., “Small persistent humid forest clearings drive tropical forest biomass losses”, Nature, vol. 649, January 2026. DOI: 10.1038/s41586-025-09870-7