On the Polish-Belarusian border, a kaleidoscope of golden, yellow and orange leaves hang from magnificent, century-old trees. The Bialowieza Forest floor is covered with lush moss, the roots of which were born after the Earth’s last ice age 12,000 years ago.
“It’s really a unique place,” said Mateusz Szymura, who grew up in the area and now heads the Nature Conservancy of Poland’s Bialowieza National Park, which lies within the forest. “It has a beauty that can’t be bought.”
But the forest – a 140,000-hectare (346,000-acre) UNESCO World Heritage site that is home to European bison, lynx, pygmy owls and 10,000 varieties of fungi – is on the edge of a geopolitical battle and migration crisis.
In July 2022, Poland completed the construction of a 186-kilometer fence along its border with Belarus and through the cross-border forest.
The 5.5-meter metal barrier on top with barbed wire and security cameras was built to prevent migrants from the Middle East and the Horn of Africa from entering Poland as a gateway to the European Union.
Katarzyna Zdanovich, a spokeswoman for Poland’s border patrol, told DW that about 3,000 guards and soldiers are monitoring the so-called “green border” in an effort to stop asylum seekers. He said about 30,000 attempts to cross the border were recorded by authorities in 2024.
Analysts say migrants are being weaponized in a “hybrid” war by pro-Russian Belarusian President Alexander Lukashenko in retaliation for EU sanctions against his country.
Impact of disturbance on biodiversity
Katarzyna Nowak, a scientist at the Mammal Research Institute of the Polish Academy of Sciences, said the creation of a physical border through Bialowieza, which previously had minimal human presence, is “a very significant shock.” “It was here before humans. Some parts of the forest were untouched for centuries.”
A year after the barrier was built, Nowak and a team of dozens of Polish and international scientists began an independent study over 18 months to assess its impact on Bialowieza’s animals and plants.
Using methods and tools such as camera traps, sound sampling, temperature and light monitors, as well as snow tracking, they found that border fortifications have led to the deaths of many animals, including reptiles, birds and bison being killed on the roads.
Their report, published in March, found that fences and barbed wire are injuring animals and preventing species such as deer, moose and wolves from crossing between the two countries. Nowak said Eurasian lynx on the Polish side that are unable to hunt, feed or breed on the larger Belarusian side are in danger of local extinction.
Although the barrier was built with gates to allow animals to pass through, they were never opened due to concerns among authorities that migrants would use them to enter EU territory.
Human presence affecting natural behavior
Scientists also observed that there are fewer animals near the border compared to other places and that loud noises such as vehicles and gunshots have had an impact on bird life near the barrier.
Furthermore, the findings point to changes in Bialowieza’s pristine ecosystem as a result of activity around the fence, including the introduction of 13 plant species with “invasion potential”. Nowak says some were probably brought in during construction of the barrier, when there was a lot of vehicle traffic.
In October, the International Union for Conservation of Nature (IUCN) declared the conservation status of Bialowieza as “critical”. The environmental organization said the border and related security activities are significantly increasing habitat fragmentation and pressure on wildlife.
Increasing number of borders around the world
The fencing of the jungle is just one example of the increasing militarization of international borders. Research shows there are currently more than 60 physical border walls in the world with further militarized borders, a sharp increase compared to the six that existed after the fall of the Berlin Wall in 1989.
These limits regularly affect local wildlife. On the US-Mexico border, white-tailed deer, American black bears and mountain lions are being blocked by more than 1,000 kilometers of walls and barriers.
In the case of Poland’s fence, which also cuts through five other EU-protected Natura 2000 areas, scientists say they don’t know enough about its impact. This happened partly because the Polish government approved its construction without an environmental impact assessment.
In a written statement to DW, the national park, which began monitoring wildlife deaths last year, said, “The number of mammals harmed by the fence is very low, and deaths are very rare.”
But Michal Zmihorski, director of the Mammal Research Institute, questions the effectiveness of official efforts.
“The most important thing is good data, but we don’t have enough. Only then can we create data-based solutions,” he said, adding that the government should fund the monitoring being done by him and his team.
“We have to take responsibility,” he said, in reference to his institute’s independent funding of the 18-month research project.
Poland’s Ministry of Climate and Environment did not respond to Zmihorski’s claim, but said in a statement that it was the responsibility of park authorities to implement “preventive measures” and that data on incidents involving animals is submitted to the ministry every two weeks. However, it did not respond to requests for such data.
Can conservation help build bridges?
Although the national park says it has taught about 4,000 soldiers about the “extraordinary value” of the forest, the institute says these efforts have not been enough to raise environmental awareness among soldiers and border guards, who have been seen littering the forest, feeding stray cats and working off-duty.
Scientists at the Mammal Research Institute are also requesting better access, including permission to take samples at border checkpoints to track zoonotic disease risk amid increased human-wildlife contact. Raccoon dogs, which spread coronavirus, are in the wild.
Meanwhile, humanitarian groups argue that there should be safe, legal routes available to migrants, meaning they would not need to cross the jungle.
Zmihorski hopes that “conservation diplomacy” – using cross-border conservation to improve diplomatic relations – can build bridges with Belarus and protect the Bialowieza Forest.
In 2022, the Slovenian government began removing 194 kilometers of fence and barbed wire installed on its border with Croatia seven years earlier to prevent illegal border crossings, believing that “security cannot be ensured by a border fence.”
Meanwhile, Poland has banned its scientists from collaborating with their Belarusian counterparts. An IUCN spokesperson said countries needed to take “urgent” joint action. IUCN and UNESCO have offered to moderate talks.
“Eventually the wall can be removed,” Zmihorski said. “It’s possible. It’s realistic. But it depends on geopolitics.”
Edited by: Tamsin Walker