Fall 1992

Think of Topsoil As...

M.J. Furniss
Forest Hydrologist, Six Rivers National Forest, Eureka, CA

Topsoil is many things. Topsoil is the great integrator. It has been called the "placenta of life on Earth," and the "balance wheel of the ecosystem."

Nothing is more fundamentally important to watersheds and living things than topsoil.

The first challenge in integrated watershed management is to get people to share fundamental values. The values of topsoil is a fine starting point for this. A reverence for topsoil is, I believe, the wellspring of all land stewardship.

Topsoil is many things. We can think about topsoil in many ways. How we treat the topsoil depends on how we think about it. We can think of topsoil as the balance wheel- or the flywheel- of the ecosystem, and the placenta of terrestrial life. Powerful thoughts. Such perspectives can be useful in persuading land managers that the topsoils entrusted to them are more than "just soil"- much more.

Here are a few more of my favorite ways to think of topsoil:

Think of topsoil as Old Growth

Topsoils must grow. Mineral weathering and the accumulation of stable humus takes very long periods of time-thousands of years. We might think of humus as recent, but dating studies reveal that humus molecules are often tens of thousands of years old. Only tiny portion of the organic matter reaching the soil persists and becomes stable humus. Countless generations of plants must contribute to make a dark topsoil.

Much attention has been paid lately to large old trees and forests; to "old growth." Yet the living topsoil is far older than the big trees it supports; orders of magnitude older.

If we could watch a forest soil and its trees in time lapse, and speed up the clock just enough to see important changes that build soil fertility happening, the trees would be quickly pulsing in and out of the soil, looking like ephemeral skins on the old growth topsoil.

Topsoil is Old Growth.

Think of Topsoil as Capital

It's easy to think of topsoil as capital. Living in a capitalist society, many of us have this perspective intuitively. The trees, crops and habitats that come from the topsoil are the profits. The amount of profit depends on the amount of capital-the fertility of the topsoil. The profit may be taken away, or rolled back into the capital.

Holding topsoil is real and enduring wealth, not subject to agreements and convention. Land appraisers talk of bare land having a "soil bank" value.

The first rule of capitalism is to never spend the capital. Those who spend capital lose their enterprise. Eroding soil is spent capital. Those who build capital have growing, enduring wealth. Topsoil is capital.

Think of topsoil as tissue.

Topsoil is a living tissue, looking like an organism turned inside out. It has a skeleton-the mineral fraction of soil that holds it together and provides surfaces to hang things on. Topsoil has living respiring matter, teeming matrices of living things of all sizes, living everywhere, thickly interacting. As these billions of creatures breathe, the whole soil breathes.

Topsoil has free enzymes that catalyze organic reactions. Humus is everywhere too, a rich web of old, super-complex organic molecules that collected in ways that they can't be eaten by soil creatures or enzymes. Humus and clay surfaces function like master organs and membranes; filtering, sorting, harboring, metering, nourishing, and holding the blood of the topsoil, it's water.

The soil solution is the blood of the soil tissue and the land organism. The soil pores, the smallest streams, are the capillaries, and feed into larger and larger veins until they become streams and rivers, and the sea.

Topsoil will bleed when cut, just like we do. If there are only capillaries, the healing may be fast. If there are arteries, like riparian areas, the bleeding may be profuse, and the healing slower. Some soils, such as those developed from DG, are hemophiliac; when cut they can't stop bleeding.

The life of the topsoil interacts via the blood, the soil water, that carries it's products to mother ocean.

Topsoil is old growth. Topsoil is capital. Topsoil is tissue. These are not analogies. Topsoil is these things. What is topsoil to you?

As land managers, we are stewards of very old growth indeed. Will it live and grow on our watch? As land manager we are keepers and investors of tremendous real wealth. Will our bank accounts and stocks be worth more next year; next century? As land managers we are physicians for the topsoil tissue and land organism, and are responsible for the health and healing of the land, the living Earth.