Tropical forests, bursting with wildlife and soaking up as much CO2 as all of Europe’s emissions, are in trouble. Sneaky vines called lianas—like passionflowers—are spreading fast, choking trees and messing with the forests’ ability to store carbon. A new study, shared on May 7, 2025, shows this isn’t just a local problem—it’s happening all over the world, and it’s getting worse.

Lianas: The Forest’s Sneaky Bullies

Ecologist Marco Visser from Leiden University compares lianas to tapeworms. “They steal trees’ resources and can double the number of trees that die,” he says. These vines climb up trees, hogging sunlight and spreading their leaves like a blanket over the forest canopy. When trees die, lianas just keep growing over the fallen trunks, turning forests into tangled messes.

Back in 2016, Visser used disease-spreading models to study lianas, but now his student, Manuela Rueda-Trujillo, has dug deeper. Her work, published in Global Change Biology, reviewed tons of studies and found lianas have been surging by 10-24% every decade for over 30 years. This isn’t just in South America—tropical forests everywhere, from Africa to Asia, are seeing the same takeover.

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Why Are Lianas Winning?

The big culprit? Rising CO2 in the air. “All plants grow faster with more CO2, but lianas get an extra boost,” Visser explains. Unlike trees, which need strong trunks to stand tall, lianas cheat by climbing trees and using less energy to make their leaves. This lets them grow faster and steal more sunlight, leaving trees in the dust. In liana-heavy forests, carbon storage can drop by up to 95%—almost as bad as clear-cutting the forest.

Spotting Lianas from Space

Visser’s team, working with researchers from the US and UK, made a cool discovery: you can spot lianas from space! Their study in Ecology shows liana leaves reflect more light and infrared than tree leaves and lie flat, blocking sunlight from reaching others. “Lianas are selfish,” Visser says. “Trees tilt their leaves to share light, but lianas hog it all.” Using cranes in Panama to check treetop leaves, they confirmed their math models, opening the door to tracking lianas worldwide with satellites.

Should We Chop Them Down?

So, should we grab some machetes and start hacking? Not so fast, says Visser. Lianas aren’t all bad—they’re native to forests and feed rare animals like monkeys and birds year-round. Cutting them could hurt wildlife that depends on them. Instead, Visser points to a bigger fix: tackling climate change. “Rising CO2 gives lianas an edge. Slowing climate change is the best way to keep them in check,” he says.

Why This Matters?

Tropical forests are Earth’s climate superheroes, but lianas are throwing a wrench in their work. If these vines keep spreading, forests could lose their power to fight climate change, and wildlife could suffer. With 83% of people wanting greener solutions, per a 2024 PwC survey, this issue is hitting home.

What’s Next?

Thanks to satellite tracking and boots-on-the-ground research, scientists can now keep an eye on lianas like never before. But time’s running out. As CO2 levels climb, these vines are getting stronger, and tropical forests are feeling the squeeze. Fixing climate change isn’t just about saving trees—it’s about keeping our planet’s carbon-storing champs in the game.

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