Scientists Plant 33,518 Trees to Build the Perfect Forest

Ecologist Jamie Pullen dips a baby witch hazel tree's roots into clear gel and places it carefully into Maryland soil. She and her team have only 15,000 more saplings to go.

Scientists at the Smithsonian Environmental Research Center in Edgewater, Maryland, are building something extraordinary on 22 acres of former farmland. They're planting 33,518 trees from 20 different species in carefully designed combinations to solve a puzzle that could help save forests everywhere.

The Functional Forests project asks a simple but powerful question: can we design forests that do multiple jobs at once? Some tree combinations focus on timber production, mixing sycamore, bald cypress, black cherry, loblolly pine and poplar. Others aim to attract wildlife, bringing together Chickasaw plum, persimmon, hazelnut and witch hazel.

The team has created 200 test plots with 38 unique species combinations. Some plots contain five species working together, while others hold just one type for comparison. They're even testing whether trees planted close together perform differently than those spaced farther apart.

Since last August, researchers and volunteers have transformed a soybean field into a living laboratory. They worked through heavy January snowfall, mapping locations with color-coded bamboo stakes and digging holes in frozen ground. When conditions are right, six staff members and eight volunteers can plant nearly 2,000 saplings in a single day.

This matters because humanity has cleared five billion acres of global forests throughout history. We continue removing about 25 million acres each year. Yet forests provide extraordinary benefits: they absorb carbon dioxide from the atmosphere, prevent soil erosion, protect water quality, cool surrounding areas and may even boost our mental and physical health.

Many large-scale tree planting efforts plant just one species because it's easier and cheaper. But monoculture forests miss opportunities that diverse ecosystems provide. This experiment will track which combinations recruit the most pollinators, resist fires best, store the most carbon and produce the most food and timber.

The Ripple Effect: Sensors will measure air and soil temperature every 15 minutes for decades to come. Drones will fly overhead tracking how each tree grows. Camera traps and audio recorders will document which animals and insects make these experimental plots their home. The data collected could guide reforestation projects worldwide, helping communities design forests that simultaneously fight climate change, support wildlife, provide resources and protect landscapes. Countries committed to restoring 865 million acres by 2030 through the Bonn Challenge desperately need this kind of science-backed guidance.

The perfect forest might not contain just one perfect tree, but the perfect blend of many species working together.