How Soil Is Formed - Soil: Reflections on the Basis of our Existence - page 27

trees, whose elongated crowns necks remind me of Donald Duck's national park
visit with his nephews. As we approach the glacier, the forest thins further and the
blueberry scrub grows higher.
A cold draught from the glacier hits us as we approach. Countless rivulets of murky
meltwater run from the ice, forming a stream that continues down into the lake.
As it moves down the slope, the glacier slowly grinds underlying gravel and stones
into smaller pieces. The ice is in constant forward motion but will retreat at the edges
during persistent or accelerated periods of melting, as during summer. The edge of the
ice will recede if this crimping exceeds the distance the glacier travels during the year.
If the ice sheet ceases to move the glacier becomes dead-ice and after it melts, it leaves
behind an expanse of pulverised rock that eventually forms the basis for soil. Soil is
the top layer of earth that is exposed to the elements and supports life forms. It begins
to form as soon as vegetation takes hold. It can be partially unsorted, as with moraine
deposited in front of a glacier, or more finely sorted into fractions that are carried away
in meltwater as silt. The silt settles as mud or sand at the bottom of the lake and forms
muddy or sandy soil when the lake eventually dries out.
Close to the glacier, the loosely piled rocks are treacherous to walk on. In winter the
water freezes, dislodging particles of gravel and sand that in spring are carried by rain-
water into the crevices, where they stabilise the more outlying rocks. This is the start of
soil formation—a process that begins when clumps of grass and sedge take root thirty
metres or so from the edge of the ice. They do not look like much, but when they die
they provide the organic matter needed for willow bushes to grow.
Return of the trees. The glacier in the photo has retreated by an average of ten metres per year over the
past century. Various plants have gradually gained a foothold: lichens, mosses, sedges, small willow
shrubs. After eighty years, soil formation has reached a point enabling the fir trees in the foreground to
take root. It is fascinating to think that the entire Nordic region has undergone this process