EcoSphere

Ground under old trees

Białowieża Forest

Podlaskie, Poland

The last large fragment of the lowland forest that once covered the European plain, with a floor that has never been cleared.

The ground under

Białowieża Forest, Podlaskie

52.7167, 23.8667 · keep going ↓

5 cmTopsoil

100.7g/kg

grams of organic carbon per kilogram of soil

The living layer: dead leaves, roots, bacteria, and the fungal threads that bind them into crumbs. Almost everything that happens to soil carbon happens here first.

30 cmThe stock

48t/haModerate

tonnes of organic carbon per hectare, top 30 cm

The ordinary range for productive farmland and managed gardens in temperate Europe.

ISRIC — World Soil Information

Modelled at 250-metre resolution from global soil surveys, and read from SoilGrids on 2026-09-01. SoilGrids publishes in versioned releases rather than continuously, so this figure is the current one until they publish again.

deeperThe network

11,158 fungal records near here

Each one is a specimen somebody found and wrote down. The species below are only the ones that fruit visibly; the threads that do the work almost never appear above ground at all.

GBIF — Global Biodiversity Information Facility

Each name links to the original record, with its collector, date and dataset.

Reading this figure

Lower than the argument above might lead you to expect, and worth sitting with. Part of it is the depth window — deadwood and deep litter are not soil and are not counted — and part is that lowland forest on sandy ground simply holds less per hectare than peat or volcanic soil does. An old forest holds an enormous amount of carbon in total, across a great many hectares and in wood the reading never sees.

Why this ground

Ground under old trees

In an undisturbed forest most of the carbon is not in the trees. It is underneath them, in fungal networks and in the litter they never finish breaking down.

Białowieża survived because it was a royal hunting reserve, protected for centuries by people who wanted the game rather than the trees. Parts of it have never been logged, which on the European plain is close to unique.

What that produces is not primarily large trees. It is deadwood, and a soil surface that has been accumulating litter and fungal biomass without interruption for a very long time. Most of the carbon in an old forest is in the ground and in what is decaying on it, not standing up.

The forest is also a long-running argument about management: whether to remove trees killed by bark beetle, or to leave the deadwood where it falls. The soil is one of the things that argument is about.

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