The Trillions Worth – Soil Biodiversity

kristy Community Development Solutions, Earth Systems Science

The Trillions Worth – Soil Biodiversity

By Luc Gnacadja*

IDN-InDepth NewsViewpoint

BONN (IDN) – Six to ten inches (18-25 cm) of topsoil are all that stand between us and extinction. There’s far more to this than food. The things that live in and grow from this irreplaceable and finite resource also keep us clothed, the air and water clean, the land green and pleasant and the human soul refreshed. Only now are we starting to comprehend how the tiny life forms in soil sustain productivity and the greater environmental balance.

Already, we know that the species that live in soil are far more abundant than first thought. Microbes in the soil make up most of the biomass of life on earth. They may lack the charisma of the tiger or the orang-utan, but the sheer prevalence of soil-dwelling fungi, archaea, bacteria, rotifers and nematodes alone puts other species in the shade.

If we placed all the microbes found in soil on one side of a scale and all surface-dwelling animals on the other, the soil microbes would quite literally outweigh them. Understanding just what their function is thus vital to our broader grasp of environmental management, climate change and human development.


Soil microbes and the tiny animals in earth provide a wide array of ecosystem services, including nutrient cycling, nitrogen fixation, decomposition and pest control, pollination, soil moisture retention, drainage, carbon sequestration, waste recycling and more.

They even play little-known but major roles in climate regulation. Research provides growing evidence that, along with dust and other particles, certain bacteria from the soil are swept up by wind to high altitudes, where ice crystals form around them to make rain. Thus, healthy, bacteria-rich soil might well encourage rainfall.

Land degradation and desertification spell the gradual death of soil’s complex web of biota. The disappearance of just a single species from this web can be devastating. Among soil’s “free services” is the harbouring of the larvae of pollinating wasps, beetles, flies and bees.

Their contribution to farming alone is extraordinary. The Food and Agricultural Organization (FAO) estimated in 2005 that of the slightly more than 100 crop species that provide 90 percent of the food for 146 countries, 71 are bee-pollinated. If we lose these “keystone” species, whole edifices will collapse.


Knowing all this, we should attribute proper economic value to soil and to the work of those who tend it. A European Commission Joint Research Centre (JRC) report in 2009 determined soil biodiversity to be “of immense economic importance”.

The report claims that “the monetary value of ecosystem goods and services provided by soils and their associated terrestrial systems … was estimated in 1997 to be 13 trillion US dollars. The soil biota underwrites much of this value.”

We sometimes forget that biodiversity includes us, too. We have long seen ourselves both as part of nature and as nature’s keepers. Some call for a shift from the old paradigm of human domination of the earth and its animals to a less greedy, less invasive coexistence with them.

But that does not relieve us of a capital duty. Because we are an all-powerful species, soil’s health — and thus our own — depends in large part on how well we sustain it. And the front line agents of this sustainability are those who live in the areas most vulnerable to degradation: the drylands.


The UNCCD’s first strategic objective is to support them in this crucial task. More than one-half of these 2 billion people subsist on less than two dollars a day. By alleviating their poverty, improving the science of sustainable land management, generating sustainable rural incomes from land-based ecosystems and building partnerships with governments, business and civil society, the UNCCD and its 193 Parties are helping them not only to inhabit, farm and use the land sustainably, but also to safeguard topsoil and its benefits for people in distant lands and for generations far into the future.

World Day to Combat Desertification 2010 takes place, as always, on June 17. This
year, it also coincides with the International Year of Biodiversity. There is no better time to remind the world of the immense value of soil’s biodiversity and of the work by farmers, rich and poor, to nurture it.

“Enhancing soils anywhere enhances life everywhere” is this year’s motto for World Day. It places soil health where it needs to be: at the very foundation of our survival and well-being.

Established in 1994, the United Nations Convention to Combat Desertification (UNCCD) is the sole legally binding international agreement linking environment and development issues to the land agenda. It focuses on the drylands, which cover 41 percent of the Earth and are in habited by over 2 billion people.

Drylands account for 44 percent of the world’s cultivated ecosystems and have provided 30 percent of all the world’s cultivated plants. However, eight of the world’s 25 biodiversity ‘hotspots’ are in the drylands and up to one fifth of the drylands have been steadily degraded since the 1980s.

The Convention’s 193 Parties are dedicated to improving the living conditions of the world’s poorest 1.2 billion resident in the drylands, to maintaining and restoring the land’s productivity, and to mitigating the effects of drought.

*Luc Gnacadja is Executive Secretary of the UN Convention to Combat Desertification (UNCCD), based in Bonn. This Viewpoint is the text of his message on the World Day to Combat Desertification, June 17, 2010.


Allan Savory
Savory Institute
Albuquerque, New Mexico, USA
Tel. 505/349-5595
Africa Centre for Holistic Management
Victoria Falls