Sustain Our Nation's Forests and Grasslands

What about the soil fauna?

A periodical cicada nymph emerging from belowground after 17 long years of subterranean life. They get to spend only a few weeks flying around as adults, but the rest of the time they are soil fauna. Photo courtesy of Roberto Carrera-Martínez.

ASHEVILLE, N.C. — When Southern Research Station research ecologist Mac Callaham and post-doctoral researcher David Coyle, D.B. Warnell School of Forest Resources, published a paper in Soil Biology and Biochemistry aimed to call attention to a subject that in recent years has received too little love from the scientific community: soil fauna and how various kinds of environmental disturbances affected soil invertebrates.

“The disturbances that nature and humans are throwing at ecosystems have an influence on soil fauna,” says Callaham. “This is going to play out on the microbes. Yet no one’s really paying attention to that right now.”

Callaham, who has been studying soil fauna for the past 25 years, noticed a disturbing trend in the scientific literature. Researchers were focusing much more on the microbes in the soil than on any of the other creatures that live in it.

When they used indexing services to look up terms like “soil microbial ecology” and “soil fauna,” the authors of the paper confirmed their fear — lots of new studies pertaining to the former, but only a few about the latter. “That’s detrimental to gaining an understanding of what’s really going on down there,” Callaham says. “Soil fauna affect the microbial components of the soil.”

As there are more environmental disturbances and their impacts get bigger, how will soil fauna respond? With fire, belowground fauna have an advantage, as the organisms on the surface that can’t retreat to deeper cooler soil die from exposure. Fire also consumes part of their habitats and food resources.

The study goes on to describe more of these impacts, including the various effects of floods, wind, invasive species, and climate change. The findings are often complex and beg many more questions. They highlight the fact that there is still much we don’t know about the creatures that live on and in our soil.