Chernobyl: The 30-year exotic forest doesn't decompose

Nearly 30 years ago, all the world's attention was on the explosion of the Chernobyl nuclear power plant in Ukraine, one of the most serious atomic disasters in human history. The world has changed since that incident, but at Chernobyl, something is still largely undeveloped: dead trees and leaves at the contaminated area do not decompose like normal plants elsewhere.

'We used to step on all the dead stalks on the ground after the first explosion in Chernobyl in 1986. Years later, these stalks remained in good shape. Meanwhile, a normal tree collapsed in your garden will turn into sawdust in about 10 years, ' said biology professor Tim Mousseau of the University of South Carolina (USA).

Professor Mousseau and Paris-Sud University expert Anders Møller conduct numerous studies on biology of radioactive areas such as Chernobyl and Fukushima (Japan). Most of their work was concentrated in the Red Forest , the famous forest surrounding Chernobyl had trees turning reddish brown before dying.

Both researchers found that dead trees in the Red Forest were almost unchanged , even after a few decades. To better understand what happened, they collected hundreds of samples of fallen leaves, scattered on the radioactive forest floor and put them in sealed bags. These leaf bags were then placed around Chernobyl area for about 9 months.

The results are staggering: Leaf samples placed in highly radioactive areas are 40% less decomposed than those in areas where there is no contamination. The degree of decomposition of leaf samples also corresponds to the level of radiation contamination in each area, according to research published in the journal Oecologia.

Scientists have known for a long time that radiation has many harmful effects on microorganisms, such as bacteria and fungi. A recent study also showed that radiotherapy may lead to serious complications in cancer patients, due to a decrease in the number of beneficial bacteria in the intestinal tract.

Mousseau's team is concerned that the accumulation of decaying leaves on the forest floor around Chernobyl over the past 28 years will create a real threat: They can become the ideal fuel for a fire. .