EcoSphere

Ground at the limit

Hekla

Southern Iceland

Volcanic ash soils that hold carbon unusually well, on an island that lost most of its topsoil to erosion.

The ground under

Hekla, Southern Iceland

63.9925, -19.6656 · keep going ↓

5 cmTopsoil

233.2g/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

103t/haHigh

tonnes of organic carbon per hectare, top 30 cm

Approaching what settled grassland and mature woodland hold, where roots and fungal networks have been left undisturbed for decades.

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

31 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.

Why this ground

Ground at the limit

Soil that is frozen, or new, or so dry that almost nothing lives in it. The edges of the range explain the middle of it.

Soils formed from volcanic ash — andosols — have an unusual mineralogy that binds organic matter tightly and protects it from decomposition. Per hectare they are among the better carbon-holding soils in the world.

Iceland is also one of the most eroded countries in Europe. Settlement brought grazing animals and the removal of birch woodland from a landscape with a short growing season, thin cover and constant wind, and much of the interior became desert. Soil conservation has been a national programme since 1907, one of the oldest anywhere.

So this is two facts about the same ground: a soil type that is good at holding carbon, in a place that demonstrated how quickly cover can be lost regardless.

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