In the Bialowieza forest, activists regularly chain themselves to a forest harvester, a massive machine that can cut down 200 trees a day. They are trying to slow down the destruction of Europe's last primeval forest.

On Friday, the European Court of Justice (ECJ) stepped in, ordering Poland to immediately halt logging in the Bialowieza Forest.

It's an interim measure the ECJ decided to take after the European Commission filed a lawsuit against Poland, arguing the logging of century-old trees poses "a major threat to the integrity" of the forest.

Environmentalists are celebrating the decision.

"This is great news for Bialowieza and the communities that depend on this remarkable forest," Dariusz Gatlowski, biodiversity specialist at WWF Poland told DW. "We expect the Polish government to immediately adhere to the court's order and stop the ongoing destruction of Europe's best-preserved lowland forest."

The interim measures are valid until the ECJ reaches a verdict. This usually takes one to two years.

The Bialowieza forest is 9,000 years old

International outcry

The Polish government started felling trees in the Bialowieza forest over a year ago as part of a "recovery program." It argued that dead wood needed to be removed to combat an infestation of bark beetles. The decision allowed for a three-fold increase in logging operations in the forest.

But environmentalists believe the forest is quite capable in recovering from the infestation by itself and argue that bark beetles are just an excuse.

"The Court's decision confirms what the European Commission, UNESCO and most of the scientific community knew and clearly stated: It's state-sanctioned logging, not a bark beetle outbreak, that is the real threat to the protected habitats and species in the Bialowieza forest," Robert Cyglicki, director of Greenpeace Poland told DW.

Poland's decision to allow logging in Europe's last ancient forest provoked uproar from international institutions.

UNESCO called on the Polish government to turn off the chainsaws and threatened to add the forest to its List of World Heritage in Danger - a move usually reserved for land threatened by natural disasters or armed conflict.

The European Commission has repeatedly and officially urged Poland to refrain from large-scale logging in the ancient forest. Poland pressed ahead regardless.

Picking battles

Poland's environment ministry tweeted that it was "delighted" at the prospect of a court case when the European Commission referred the country to the ECJ. In another tweet the ministry said it had "hard data" on the Bialowieza forest and looked forward to presenting it before the tribunal.

Environmentalists have dubbed Poland's Environment Minister Jan Szyszko "minister for logging." Szyszko also issued a law earlier this year allowing private landowners to chop down trees on their property without applying for permission.

Some activists are worried the government will continue logging in the Bialowieza forest, in spite of the EJC ruling.

Citizens in Warsaw protest against logging operations in the Bialowieza forest

"I'm not very optimistic," Tomasz Wesolowski, a forest biologist at the University of Wroclaw, told DW. "The foresters will continue to log, destroy the forest and make money, while the citizens have to pay for their stupidity. We'll end up paying the fines with our tax money."

But political observers don't think Poland would go so far as to ignore an ECJ ruling.

Aleks Szczerbiak, professor of polish politics at the University of Sussex in the UK, says the Polish government is careful to calculate the strategic political costs of its actions. Right now, the country is more likely to pick its battles with the commission over judicial reform and a quota for refugees.

"I would be very surprised if [the logging] was such a priority to accept financial sanctions - unlike the migration issue and the judicial reform," Szczerbiak told DW.

The commission has said Poland's voting rights in EU decision-making could be suspended if the government removes judges from the supreme court. It also announced plans to pursue legal action against Poland for refusing to participate in a scheme to distribute refugees more equitably among EU member states.

A woodpecker perches on a tree in a protected area of the forest

Not too late

On the ground in the Bioalowieza forest, activists are anxious for the ECJ's order to be implemented as quickly as possible.

"Every day of continued logging is destructive for the forest," Krzysztof Cibor of Greenpeace Poland told DW. "They are still destroying the really beautiful part of the forest. It's important to halt it as soon as possible."

The forest, which extends over 1,500 square kilometers (580 square miles) across Poland and Belarus, is home to more than 5,500 plant species and 11,000 animal species, including rare bison and lynx.

Environmentalists say this precious the biodiversity is at risk - but it's not too late yet.

"The forest will recover if they stop logging now," Cibor says. "It will take a long time, though."