Four years after Poland built a steel fence across one of Europe’s most precious forests, scientists and residents are still grappling with officialdom to access basic data on its environmental impact.
In Teremiski, you first hear about the border from a woman’s kitchen.
“Coffee?” she asks, sliding a plate of cookies across the table as if nothing in the world has changed.
“Just water, please,” we answer. It’s a small habit we have picked up in the borderlands of northeast Poland: you never know how long you will stay, or what you may need to carry next.
A cat loops around chair legs. Her name is Depression.
“Yes, Depression,” our host says without irony. “She was sick. That’s what we called her.”
A minute later, the conversation turns from domestic to practical. Ela, who lives a few kilometers from the heavily guarded border with Belarus, describes what she takes into the forest now.
“Before, you took a map,” she says. “Now you take more water. Maybe food. Something that might keep someone alive.” Someone like one of the thousands of asylum seekers who over the past five years have tried to cross from Belarus into EU member Poland.
The Bialowieza Forest is a transboundary ecosystem shared by Poland and Belarus. Only a part of it is protected as national parks on both sides of the border. The entire forest complex covers roughly 1,500 square kilometers, while Bialowieza National Park in Poland protects about 105 square kilometers. The forest shelters large tracts of undisturbed old-growth trees and is home to more than 250 species of birds and 59 animal species, including some 900 individuals of the forest’s signature animal, the European bison.
Two parallel realities have coexisted in the Bialowieza Forest for the past five years. Poland completed a permanent steel barrier in June 2022, running for 186 kilometers along the border, far beyond the national park boundaries, crossing several Natura 2000 protected areas. One reality takes the form of a five-meter wall of steel, lights, and cameras – the Polish state’s answer to a political crisis on the eastern edge of the European Union.
The wall was built in 2022, when thousands of migrants from the Middle East, Africa, and Asia arrived in Belarus and pushed toward the border. Polish authorities accused the Belarusian government of orchestrating the movement as a form of “hybrid warfare” in retaliation for EU sanctions imposed over the violent crackdown on critics of the regime. Warsaw responded by declaring a state of emergency along the border and later building a permanent barrier intended to stop irregular crossings from Belarus.
The other side of the new reality is mostly hidden: people moving through the woods at night, sleeping outdoors, falling ill, and sometimes dying. The wall was meant to be a boundary – for people, not animals. In practice, it has become a pressure system – on residents, on those crossing, and on the ecosystem itself.
We came here to investigate a narrower question than border politics: what an infrastructure project did to a UNESCO World Heritage forest – and why, years later, so much about its environmental impact remains difficult to independently verify. In particular, its effect on the movement of the forest’s “big four” residents: bison, wolves, moose, and lynx.
Teremiski’s residents describe the change in repeating details. The “go-to-the-forest” bag now includes a thermos and a rescue kit. And the animals, especially bison, have become less predictable.
A large bison bull has repeatedly wandered into the village from the forest. The more often wildlife enter inhabited places, the higher the chance of conflict and accidents. A few months ago, a tourist approached a bison too closely and was attacked. According to Rafal Kowalczyk, former director of Poland’s Mammal Research Institute, the animal was saved only because witnesses confirmed the tourist ignored warning signals and basic rules of behavior around wildlife.
Residents also describe a different kind of isolation: not ecological, but personal. “No one cares what it means to live here,” Ela tells us. “Very rarely did anyone ask uswhat everyday life looks like.”
The Shortcut: How the Wall Bypassed Ordinary Rules
In spring 2022, construction crews moved into the forest to build a permanent barrier. Polish authorities argue that the barrier is necessary for national security and for protecting the EU’s external border. Officials maintain that controlling migration flows remains the government’s priority, even as debates about environmental impacts continue.
The main contractor was Budimex, one of Poland’s largest construction firms, owned by Spain’s Ferrovial. In the wake of the big construction project, local researchers began documenting what heavy machinery left behind: damaged trees, concrete, plastic waste, and human refuse along forest roads churned into ruts.
We heard about this “inventory” before we saw it. Then we met the people who had monitored it: residents and scientists who returned to the same spots again and again, photographing, describing, and mapping the evidence.
The project was completed in June 2022. Most of the 186-kilometer barrier lies outside the national park but still crosses protected Natura 2000 habitats and other ecologically sensitive forest areas. The official price tag was 1.6 billion zloty (375 million euros), including an electronic surveillance system.
How was it possible to build such an intervention without the standard environmental checks? The answer is procedural: a special law. In October 2021, then-Polish President Andrzej Duda signed legislation that effectively removed the investment from normal administrative pathways. In practice, that meant bypassing the environmental-impact assessment that projects of this scale would normally require under EU rules and sidestepping Poland’s obligations under the Espoo Convention on transboundary environmental impacts.
Authorities argued that time was a luxury they did not have. We asked the Ministry of Climate and Environment whether any environmental analyses were conducted for either construction or operation. We received no reply.
The legal shortcut had another consequence that is central to this story: it narrowed public access to information. Even today, when the physical wall is finished, the paper trail around its ecological footprint remains fragmented and often inaccessible.
What We Asked For – And What We Were Told
We filed formal information requests to understand what assessments the state carried out, if any. We wrote to the Regional Directorate for Environmental Protection (RDOS) in the regional capital Bialystok, the Border Guard, and other state bodies involved in implementing the barrier.
RDOS responded that the wall had been built under the 29 October 2021 act on state border protection legislation that explicitly exempted the project from environmental protection rules, spatial planning, laws regulating water use and construction, and even standard access to environmental information.
In other words, the regional office tasked with safeguarding the environment carried out no independent audits, assessments, or analyses during construction. Oversight was concentrated in a government “task force for the preparation and implementation of state border security” that included the General Director for Environmental Protection. Any documentation about potential impacts on Natura 2000 sites would be held at the national level and could be released only by the General Directorate for Environmental Protection, according to the office of Bialystok RDOS director Dorian Kozlowski.
RDOS also stated it had recorded no complaints about environmental damage and had no information about post-construction monitoring.
The Border Guard, acting as investor, resisted disclosure, telling us that “technical aspects” of the barrier do not constitute public information under the rules governing access to public data. In practice, this position blocks independent scrutiny of basic environmental questions: where cameras are placed, what they record, how the gates at animal crossings operate, and how often animals approach or attempt to cross.
The Border Guard did confirm that it used 1.3 billion zloty in domestic funds on the barrier and that after completion there were no extra costs beyond routine repairs. It also reported no current plans to expand the barrier.
For residents and scientists, the pattern is familiar: a physical structure that cannot be ignored, and an information regime that is difficult to penetrate.
Two Barriers, One Forest
The leader of Belarus’s largest pro-government youth organization, BRSM, Aleksandr Lukyanov, in 2023 called Poland’s treatment of asylum seekers at the barrier an act of “barbarism” and claimed that in one year, 23 people had died trying to cross the border. In 2022, the then-minister for natural resources and environmental protection called the fence a “politicized project” and “a monument to human arrogance.” The ministry has flagged the environmental damage caused by the barrier and disruption of the hydrological regime of adjacent ecosystems. Those arguments are real – but the Belarusian narrative often omits a crucial detail: an older barrier has stood on the Belarusian side since the late 1980s.
Locals call it the Sistema – a roughly two-meter fence that has constrained the movement of large mammals inside the forest for decades. A Belarusian scientist we spoke to asked to remain anonymous for safety reasons.
“Some species already had trouble crossing the border before,” the scientist told us. “But now it’s much worse. In 2017 we discussed removing the Belarusian fence. Today that hope is gone.”
New obstacles on the Polish side made the situation worse. In places, concertina wire – known locally as the “Bruno spiral” – was installed, including near river valleys. Scientists say this wire has caused severe injuries and mortality of animals attempting to cross it.
While official environmental monitoring remains limited, independent researchers have begun documenting what is happening along the barrier.
Katarzyna Nowak, a biologist studying the impact of military presence on the border, and her colleagues installed 36 camera traps along the forest edge and nearby roads. During 18 months of monitoring that started in August 2023, they collected more than 50,000 photographs.
The results suggest that the border infrastructure is already reshaping how wildlife uses the forest. Cameras placed deep in the forest recorded significantly more wildlife than those near the barrier, where human activity was detected more than twice as often as animal movement.
“The influence of militarization on the border goes beyond the border zone itself,” Nowak said during a recent research presentation.
Her team also documented heavy construction traffic during the building phase. On one forest road alone, monitoring recorded up to 130 vehicles per day. Researchers found damaged roadside trees, fragments of barbed wire, fuel leaks, and plastic waste left behind by construction crews.
Photographic evidence suggests that border infrastructure apart from the 2022 barrier is also being shaped by concerns about defense rather than migration. This image released by Northwestern University’s Knight Lab shows “dragon teeth” anti-tank obstacles placed along a road in August 2025.
Claims from the Belarusian side about the impact of the barrier are hard to verify. In 2024, the state news agency Belta quoted a mention of the border wall in a joint human rights report by the Russian and Belarusian foreign ministries: “There is no expert assessment of the measures taken by Warsaw to build a wall on the border with Belarus, ostensibly to protect against illegal migration flows, as well as of the destructive environmental consequences that they have already caused and will cause in the future.”
In 2022, a state media interview suggested deer numbers in a hunting reserve had halved within a year because of the Polish wall – without presenting data. With limited access and politicized messaging, it is difficult to establish what happened to those animals. The forest is split between two states and two information systems; both constrain verification in different ways.
“No One Asked Us”
Scientists from the University of Warsaw monitored the construction footprint from February to November 2022. Along one forest road they visited 26 times, they recorded dead reptiles, amphibians, and birds – some protected by Polish law – that had been run over by construction vehicles. Many carcasses disappeared quickly, taken by scavengers, suggesting that observed mortality likely understates reality.
“We had the tools to monitor properly before construction started,” says Michal Zmihorski, a professor at the Mammal Research Institute of the Polish Academy of Sciences. “No one asked us to.”
Scientists emphasize that even without expensive multi-year telemetry, the state could have learned a great deal about wildlife near the border through simpler methods such as tracking, transect lines, camera traps, and presence monitoring. In fact, in some areas, scientists did install such equipment to document wildlife activity.
Researchers also attempted to obtain camera footage from the barrier system. They were told materials were classified – even though selected clips later appeared in official communication. The result is a basic knowledge gap: independent scientists still cannot answer, with confidence, which species approach the wall, where, and how often.
Katarzyna Nowak also led a project on the ecological footprint of border barriers in 2022–2023. She describes fieldwork that often resembled negotiating every meter of access. Camera traps had to be positioned so they recorded the forest but did not “see” the barrier – a condition imposed by the Border Guard and regional environmental authorities. The team combined camera traps with transects, snow tracking, sound recording, and inventories of human traces (from rubbish to tire marks).
The data they collected points in one direction, Nowak says: increased human presence – vehicles, soldiers, Border Guard officers, and personnel from other services − near the border compared with control roads, and fewer animal tracks in the border zone consistent with avoidance.
“We can see how this affects the distribution of mammals and their activity. Preliminary results indicate that species like bison, wolves, and red deer appear far less often near the border today than before the barrier was built,” the scientist said.
The wall also changed what eats what. Food waste around military and Border Guard posts attracts foxes, raccoons, dogs, and feral cats. That can create local hotspots for disease transmission and alter predator dynamics in ways difficult to reverse. Tracking in winter 2024 added nuance: some small mammals and mid-sized predators can cross secondary fences and barbed wire, and may even pass the main barrier in specific spots. But large mammals appear far less often near the border today than before 2022, researchers say.
According to the researchers’ field notes, deer tend to move parallel to the barrier rather than attempt crossings. Tracks of lynx have been recorded approaching the fence and turning back.
On an 18-kilometer stretch of the border, scientists recorded around 140 tracks of medium-sized predators and roughly 40 traces of deer, but very few successful crossings of the main barrier.
One risk concentrates on the lynx. Scientists warn that further genetic isolation could push the population, now just 10–15 individuals, toward irreversible decline. The wall is not the only factor shaping the forest, but it has become a new, hard line in an ecosystem that relies on permeability.
Listening to the Border
The border is not only a visual structure; it is an acoustic one. Researchers analyzed the forest’s soundscape, running continuous recordings in winter 2024 for a week and recording for more than eight months in the strict reserve of the Bialowieza Forest – the most protected core area of one of Europe’s last primeval lowland forests, where human activity is heavily restricted to preserve old-growth ecosystems and rare species.
The recordings indicate that human-made sounds can travel deep into the forest within a belt of roughly 100 to 250 meters from the border – wide enough to affect nesting, hunting, and movement for species sensitive to disturbance. Conditions also fluctuate: quieter phases alternate with periods of patrol activity and other noise, so the full acoustic variability may take years to capture.
For the team, snow tracking proved most revealing. It showed which species attempt crossings and which animals linger near posts for discarded food. Informal conversations with soldiers added details: foxes may cross the main barrier, cats reportedly come from Belarus, and bison approach the barrier on the Belarusian side in at least two locations.
That raises a disturbing possibility: some large mammals may be effectively boxed in between Poland’s wall and Belarus’s older fence. According to Nowak, the strip between the two barriers covers about 37 square kilometers, mostly within Poland’s Bialowieza National Park, and is fragmented into several sections connected by narrow corridors where the fences run close together – passages large animals may be reluctant to use.
“Last August we watched a bison bull stand just behind the Polish barrier, looking west,” she says. “In an ideal world, Poland and Belarus would cooperate to free these animals as soon as possible.”
Closed Gates
As the barrier was under construction, state officials drew attention to 24 wildlife corridors for bison, wolves, deer, and lynx. On paper, these crossing points are the compromise – the promise that the wall could be both a border and a permeable structure for nature.
If corridors stay shut and gates closes, the ecological logic is brutal. Large mammals are prevented from moving between habitats and from mixing genetically. Over time, isolated populations become weaker: they expend more energy, suffer lower reproductive success, and are more vulnerable to disease and inbreeding. In a primeval forest where genetic exchange once happened across rivers and clearings, the wall creates a fixed, administrative topology.
The obvious question – why gates are not opened and under what criteria they could be opened – is also the question the state is least willing to answer. Without operational transparency, “corridors” remains a word on an infographic rather than a functioning mitigation measure.
How to Minimize the Damage?
Given current politics and an ongoing migration crisis, dismantling the barrier soon appears unlikely. If it remains, the debate shifts from “take it down tomorrow” to “what must be done so the damage doesn’t compound.” Scientists warn that the greatest long-term risk may be genetic isolation. Large mammals such as lynx, wolves, and moose rely on movement between populations on both sides of the border. If the barrier prevents this exchange, small populations could gradually lose genetic diversity, increasing the risk of disease and long-term decline.
In their 2024 joint report on Bialowieza, the International Union for Conservation of Nature and UNESCO warned, “the Polish border security infrastructure combined with the existing Belarusian ‘Sistema’ are blocking the majority of wildlife movements” and forecast that “Lack of action to address this impact through effective mitigation measures will inevitably lead to two functionally disconnected wildlife protected areas.”
A number of recommendations for better monitoring of wildlife and improved public access to information about the border wall emerge from the interviews for this article and studies such as this one from the Mammal Research Institute and the University of Warsaw’s Bialowieza research station:
- long-term monitoring of key populations (especially lynx, moose, and wolf);
- transparent rules for when and how gates and wildlife corridors can open;
- limiting service traffic and preventing further road expansion in protected zones;
- rigorous waste management at posts;
- and a remedial plan for Natura 2000- and UNESCO-protected areas, with deadlines and responsibilities clearly assigned.
Some monitoring is carried out now, but it was not designed around the barrier. In early 2025, a UNESCO state-of-conservation report noted that partial studies had been commissioned in 2024 – two years after construction ended – and recommended a multi-institution team (made up of site managers, ministries, Border Guard, army, and scientists) to design comprehensive monitoring and remedial actions.
In late 2025, Poland’s State Council for Nature Conservation issued an urgent position paper arguing that Bialowieza – still recovering from the shock of illegal logging in 2017 – faces new pressure from the border barrier, expanding infrastructure, and drainage of habitats. Experts called for immediate measures: limiting traffic on forest roads, restoring wetlands, and developing integrated protection plans.
Residents don’t need reports to sense the shift. In Teremiski, Basia describes years when the border existed mainly for people, not animals. “Once a bear came to us from Belarus,” she recalls. “We photographed it eating honey. Wolves crossed the border when we walked nearby. For them, politics didn’t exist.”
Now politics has a five-meter spine of steel. The ecological bill is still being counted – and, as our requests show, part of the bill is informational: without access to data and a functioning monitoring system, society cannot reliably evaluate what the wall has done, what mitigation works, and what is failing.
Nikola Budzinska is a Polish journalist who specializes in cross-border and environmental reporting. Anastasiya Zakharevich is a Belarusian journalist with extensive knowledge of local communities and protected areas along the Belarusian border.
This article was produced with the support of Journalismfund Europe.
