Proforestation: The case for leaving trees alone

Older, wiser, wetter: The overlooked value of ancient forests

Forest in the Pacific Northwest

In a quiet corner of northern New York, the white pines of the Adirondack Forest Preserve rise like sentinels, untouched for over 125 years. Their silence speaks volumes. These towering trees—some 150 feet tall and over a century old—stand as evidence of a counterintuitive climate solution: do nothing.

Well, not quite nothing. Proforestation, a term coined by academics William Moomaw and Susan Masino in 2019, refers to the practice of leaving existing forests to grow unbothered until they reach their full ecological potential. Unlike reforestation or afforestation, which involve planting new trees, proforestation champions mature forests precisely because of what they already are. “It’s the existing forests that we have that are doing the work,” says Moomaw. And quite a bit of work at that—forests annually remove nearly 30% of human-generated CO₂ emissions. The largest 1% of trees by diameter in a mature forest can store half its carbon.

But their value transcends carbon. Old-growth forests are biological fortresses, rich in complexity: downed logs, snags, towering trunks, and diverse canopies. This intricate architecture provides shelter to species that would otherwise vanish—from spotted owls in the Pacific Northwest to elusive salamanders in mossy understoreys. Strip away the ancient trees, and you unravel webs of life evolved over centuries.

They are hydrological engineers, too. With deeper roots and broader crowns, old trees drive evapotranspiration, moving water from soil to sky. Cut them down, and landscapes dry out.

As Masino put it bluntly to Sruthi Gurudev, “Nature needs room to breathe. We can’t leave everything open to manipulation and extraction. It’s deadly.”

There is no app to replicate the wisdom encoded in an ancient forest. Genetic diversity—essential for adapting to an unpredictable climate—cannot be replanted wholesale. Nor can the cultural or spiritual gravity of landscapes that predate the combustion engine.

Yet old-growth logging persists, a hangover from an era when dominion trumped deference. Of the old forests that once blanketed the U.S., perhaps a tenth remain.

“They are the only survivors of American handiwork,” said ecologist Beverly Law.

Letting forests grow might sound passive, but in the age of climate chaos, patience is an act of radical stewardship.

Gurudev’s piece, Beyond reforestation, let’s try ‘proforestation’

CITATION: Gilhen-Baker, M., Roviello, V., Beresford-Kroeger, D., & Roviello, G. N. (2022). Old growth forests and large old trees as critical organisms connecting ecosystems and human health. A review. Environmental Chemistry Letters, 20(2), 1529-1538