Walk through parts of northwestern Costa Rica today and you might assume the forest around you has always been there.
Understanding the importance of Costa Rica biodiversity is crucial for the preservation of these ecosystems.
Towering trees shade the trails. Monkeys move through the canopy. Jaguars roam the landscape. Birds, bats, insects and countless other species occupy a forest that feels ancient.
But in many places, the forest is younger than the people who work in it.
Only a few decades ago, large stretches of this land were cattle pasture. Forest had been cleared and burned for ranching and agriculture, part of a transformation that made tropical dry forest one of the most threatened ecosystems in the world.
Today, much of that forest is back.
This revival showcases the incredible efforts to maintain Costa Rica biodiversity.
Its recovery is at the heart of Área de Conservación Guanacaste, or ACG, a protected area in northwestern Costa Rica that stretches from the Pacific Ocean across tropical dry forest and rain forest and up the slopes of several volcanoes.
ACG now protects roughly 425,000 acres and an extraordinary concentration of life—approximately 2.6 percent of the planet’s biodiversity.
The story of how it came to be offers a hopeful lesson about what is possible when nature is given time, space and protection.
Beginning in the 1980s, conservationists Daniel Janzen and Winnie Hallwachs, working alongside Costa Rican colleagues and communities, began pursuing an ambitious idea.
Rather than simply protecting the fragments of forest that remained, why not rebuild an entire tropical ecosystem?
That meant acquiring former farms and cattle ranches surrounding the surviving forest and connecting them into a much larger protected landscape.
It also meant controlling the human-caused fires that swept through the region during the dry season and prevented young forests from taking hold.
Then, in many places, conservationists did something deceptively simple: They let nature do the work.
This was not primarily a forest restoration project built around planting millions of trees.
Once cattle and fire were removed, seeds arrived naturally through wind, birds, bats and other animals.
Young trees grew. Forest patches expanded. Previously separated habitats began connecting again.
Wildlife returned.
Year by year and decade by decade, former pasture became forest.
That transformation created habitat for an extraordinary range of species.
Jaguars, once under enormous pressure from habitat loss and conflict with people, now live and reproduce within this increasingly connected landscape.
Monkeys, tapirs, birds and bats move through restored habitat. Thousands of less conspicuous species—from insects and fungi to plants and microorganisms—are also part of the recovering ecosystem.
Just as importantly, the project has never been only about land.
ACG developed a conservation model rooted in Costa Rica itself.
Local residents became firefighters, researchers, educators, park staff and highly trained biodiversity specialists.
Children from surrounding communities began visiting the forest as an outdoor classroom.
Scientists from Costa Rica and around the world have spent decades studying the ecosystem, generating knowledge that reaches far beyond the boundaries of the conservation area.
The Guanacaste Dry Forest Conservation Fund, or GDFCF, a U.S.-based nonprofit, has supported this work for nearly 30 years.
Working alongside ACG and Costa Rican partners, GDFCF helps provide resources for land acquisition, forest protection, scientific research, environmental education and the people whose daily work sustains this remarkable conservation effort.
Despite decades of progress, serious challenges remain.
Climate change is increasing the threat of drought and wildfire. Restored forests require continued protection, management and monitoring.
There are also important pieces of habitat that could still be added to create an even larger and more resilient landscape.
The future of Guanacaste’s restored forests will depend on maintaining the same long-term commitment that helped bring them back.
Perhaps the most important lesson from ACG is one we do not hear often enough.
Environmental stories are frequently stories about what we are losing.
The forests of Guanacaste tell another story: Under the right circumstances, some of what has been lost can come back.
It takes patience.
It takes people, land, funding and decades of commitment.
And sometimes, it takes knowing when to get out of the way and let nature take over.
In Guanacaste, a forest that was disappearing is growing back.
Nearly 40 years later, that may be one of its most important lessons for the rest of the world.
