Soil's Tiniest Organisms Could Solve Huge Problems

NAIROBI, Kenya, November 29, 2002 (ENS) - There is a wealth of new species under our feet awaiting discovery, especially in the still unknown portions of the tropics, which represents "a huge new genetic resource," the top United Nations environmental agency said today. Amoebas, protozoa, nematodes, mites, termites, ants, earthworms. Life forms that inhabit the soil are the least known of all life forms on Earth, and scientists are discovering that they can profoundly affect planetary patterns.

Calling it "the largest source of untapped life left on Earth," the UN Environment Programme (UNEP) has announced a new $26 million project to understand and utilize the life forms underground. It is one of the more "unusual, curious but absolutely vital projects UNEP has undertaken," said the agency's executive director Klaus Toepfer as he announced the project today.


Mark Kinney and Conrad Field construct a soil profile on native lands near Homer, Alaska. (Photo courtesy USDA Natural Resources Conservation Service)
In the hope that this "genetic treasure trove" will yield new drugs, antibiotics, and industrial products, the project will initially target "below ground biodiversity" in seven tropical countries - Brazil, Mexico, Cote d'Ivoire, Uganda, Kenya, Indonesia and India. These countries were chosen for study are those thought to have the richest below ground biodiversity.

Backed with $9 million funding from the World Bank Group's Global Environment Facility (GEF) and support from other donors such as the Rockefeller Foundation, the Conservation and Sustainable Management of Below-Ground Biodiversity project will catalog and classify "the life forms below ground" said Ahmed Djoghlaf, head of the UNEP/GEF Division, based at UNEP headquarters in Nairobi.

These miniscule life forms can be as tiny as one-tenth of a millimetre (100 micron). The smallest amoebas are even less than 10 microns in size, while bacteria weigh in at one to three microns.

One gram of tropical forest soil may contain up to 40,000 individual bacterial species, the agency said today, many of which have never been described.

"There is an urgent need to assess, classify and record the life forms below ground," Djoghlaf said.


The 200 species of mites in this microscope view were extracted from one square foot of the top two inches of forest litter and soil. Mites play a role in soil nutrient release. (Photo by Val Behan-Pelletier, Agriculture and Agri-Food Canada courtesy USDA)
Just as increasing intensification of agriculture and clearing of forests for farmland have taken their toll on wild animals and plants, they place the microscopic world of underground bacteria and fungi at risk of extinction and decline in the abundance and numbers of species.

UNEP Executive Director Klaus Toepfer said, "The life forms living just below our feet are the most understudied organisms on the planet. When people think of where new species might be found, they tend to think of the rainforests, mangrove swamps or place like mountain peaks, not millimetres below their toes."

Toepfer said researchers are now realizing that the world's soils, especially topical soils, are teeming with life. They "harbor more undescribed species than dwell on the Earth's surface," he said.

Expressing delight at UNEP's involvement in "this pioneering work." Toepfer said, "Harvesting the secrets of this understudied realm promises huge benefits and improved knowledge towards the goal of delivering sustainable development, towards eradicating poverty."

Bacteria and fungi in the soil can clean drinking water sources. They help eliminate pollutants and germs from groundwater as it percolates through the soil to reservoirs, boreholes and other freshwaters sources.


Female nematode (Photo courtesy USDA Agricultural Research Service
Organisms living in the soil also "play a key role in the release of carbon dioxide, methane and other greenhouse gases from the land into the atmosphere," scientists associated with the project said as part of the UNEP statement today.

Understanding and unraveling the role of these microscopic creatures in the carbon cycle may help the land absorb more greenhouse gases to help cool the planet.

Soil-dwelling beneficial life forms may also play a role in reducing crop, livestock and human diseases, UNEP said today, as they attack and neutralize plant, animal and human pests and pathogens.

Earthworms, termites and other soil burrowing organisms influence the amount of rainwater soils can absorb. Soils depleted in such organisms are more prone to drought and run-off, which in turn increases the risk of flooding and erosion with consequences for river water and coral reefs.


Earthworm cocoons (Photo by Clive A. Edwards, The Ohio State University, Columbus published in the USDA's Soil Biology Primer)
"We may be losing many important and useful species from the world's soils without even knowing it," warned Djoghlaf.

The project is coordinated by Mike Swift, director of the Nairobi based Tropical Soil Biology and Fertility Institute of the International Center for Tropical Agriculture (CIAT), one of the research centers in the CGIAR agricultural network.

The Consultative Group on International Agricultural Research (CGIAR), an association of public and private members supporting a system of 16 Future Harvest Centers, works in more than 100 countries, mobilizing the "cutting-edge science" that CGIAR says aims to reduce hunger and poverty, improve human nutrition and health, and protect the environment.

Increasingly, bioengineering and genetic modification of crops underpins CGIAR's approach to those issues. Still, CIAT has other offerings, among them a new climate database tool based on 20 years of weather data. The newly published CD-ROM version 1 of MarkSimTM generates Simulated Weather Data for Crop Modeling and Risk Assessment.

The Below-Ground Biodiversity Project Guide to
"Mini Beasts, Wiggle Worms and Fellow Soil Dwellers"

It is estimated that in one gram of forest soil there are up to 40,000 individual bacterial species many of which have never been described.

It is thought that only five percent of the world's living fungi have been described. Of the 72,000 described species, up to 35,000 could be classed as soil living.

Protozoa include amoebas and flagellates. Some 1,900 soil-living protozoa have been described, which may be only 10 percent of the species alive.

Some 15,000 individual nematode species have been described. It is estimated that there may be more than be as many as 100,000 species.

The 45,000 described species of spider-like invertebrates known as mites are thought to represent just five percent of the total.

There are numerous groups of soil-dwelling insects, including termites. More than 2,000 termite species have been described.

Nearly 9,000 ant species have been described.

Over 3,600 earthworms have been described, and scientists say double this number may exist in the wild.

Most protozoa eat bacteria, says Elaine Ingham of Oregon State University, but one group of amoebae eat fungi, the vampyrellids that suck the life out of their prey.

"The perfectly round holes drilled through the fungal cell wall, much like the purported puncture marks on the neck of a vampire’s victim, are evidence of the presence of vampyrellid amoebae," says Ingham. "The amoebae attach to the surface of fungal hyphae and generate enzymes that eat through the fungal cell wall. The amoeba then sucks dry or engulfs the cytoplasm inside the fungal cell before moving on to its next victim."

Pictures, facts and figures on soil biology and below ground biodiversity are online at the website of the U.S. Department of Agriculture Natural Resources Conservation Service's Soil Quality Institute, UNEP recommends. Find it here.

The "Soil Biology Primer" edited by by A.J. Tugel, and A.M. Lewandowski the source of the photos in this article, is online at: