Plants could help authorities detect dead human bodies in woodland

In an article published Thursday in the journal Trends in Plant Science, researchers from the University of Tennessee said tree and shrub canopies could be used as a search "asset" to help guide rescue teams to human remains.

This is because chemical changes in the ecosystems around human remains, referred to by researchers as "cadaver decomposition islands," alters the soil and surrounding plant roots and leafs.

This in turn, they said, "might lead to plant foliar compositional changes that could be detected remotely."

A team of botanists, anthropologists and soil scientists from the university will begin experimenting with the so-called cadaver islands to better understand how plants could help reduce the time spent on "painstaking" on-foot pursuits and aerial searches.

The research will be conducted at the university's Anthropology Research Facility, known as the "body farm," where scientists examine the process of human body decay under different conditions and how it impacts nearby plants.

The authors cautioned that the research was in an early phase, with any feasible use of plants as a body recovery tool still "several years away."

However, they said the early findings were "exciting" and that they hoped in future to scale up technology that would scan plants for specific fluorescence or reflectance signals that indicate human remains.

"In smaller, open landscapes foot patrols could be effective to find someone missing, but in more forested or treacherous parts of the world like the Amazon, that's not going to be possible at all," said senior author Neal Stewart Jr, a professor of plant sciences at the University of Tennessee, in a statement. "This led us to look into plants as indicators of human decomposition, which could lead to faster, and possibly safer body recovery."

"The most obvious result of the islands would be a large release of nitrogen into the soil, especially in the summertime when decomposition is happening so fast," Stewart added.

But the team faces challenging hurdles, including the need to have scanners recognize human bodies as distinct from other large mammals, such as deer.

In order to do that, they must first better understand metabolites -- small molecules -- specific to the breakdown of human remains that could influence plant appearance, researchers said.

"Once diagnostic spectra are compiled, researchers can begin to think about scaling up to drones and other tech that can analyze a wide stretch of area in a short time," Stewart added.