The Forest

The single largest driver of forest loss isn't logging in the way people often imagine. It's agriculture. Across the tropics, forests are cleared to make room for cattle pasture, soy fields, palm oil plantations and the export commodities that feed distant supply chains. The Amazon, the Congo Basin and Southeast Asia each tell a version of the same story: land is worth more, in the short term, with the trees gone. The chainsaw is really an economic instrument.

The scale is hard to hold in the mind. The world has lost something on the order of a third of its forest cover over the long span of human history, with much of that loss concentrated in the last few centuries and a sharp acceleration in the tropics since the mid-twentieth century. In recent years the annual net loss has run in the millions of hectares — an area of tree cover disappearing each year larger than many countries. Some of that is offset by regrowth elsewhere, but the forests being lost and the ones growing back are rarely equivalent.

Faced with all this, the response of the last two decades has often taken a satisfying, countable form: plant trees. Governments and companies have pledged billions of them. Campaigns have staged mass plantings — volunteers putting hundreds of millions of seedlings in the ground in a single day, records set and celebrated. The appeal is obvious. A tree planted is a fact you can photograph, a figure you can announce, a gesture almost everyone can get behind.

The problem starts after the photo. A striking share of planted seedlings don't survive their first years. Follow-up studies of large restoration schemes have repeatedly found survival rates well below half, sometimes far below, when the wrong species are chosen for the site, when there's no plan to tend them, or when the land was cleared again for farming a few seasons later. In one much-discussed Turkish mass-planting effort, a large fraction of the saplings were reported dead within months. The seedling in the ground is the beginning of the work, not the end of it, and the counting usually stops at the beginning.

The gap between a planted stand and a living forest is, in the end, the gap between a thing and a process. You can plant a tree in an afternoon. You cannot plant a forest, because a forest isn't an object you install — it's a set of relationships that assemble themselves over decades, given the right soil life, the right mix of species, the seed-dispersing animals, the accumulated dead wood, and above all the time to grow old. A seedling is a bet on that whole process taking hold. Very often it doesn't.

This is why ecologists increasingly argue that protecting existing forest is worth more than planting new trees, hectare for hectare. An intact forest already contains the network, the age, the complexity that a plantation would need a hundred years and a great deal of luck to approach — if it ever did. Letting degraded land regenerate on its own, seeded by nearby survivors, often produces a richer result than planting, because it lets the system rebuild in its own order rather than forcing a design onto it.

Step back into that old forest one more time — the dim light, the give of the ground, the fungal threads running under a single footstep. Almost none of what makes it a forest could be installed by a planting crew. It was assembled over a century or more, in an order no one designed, out of relationships that mostly happen where we can't watch them. That's the thing under pressure, and it's the thing a freshly planted field of saplings does not yet contain.