A team of researchers suggests that radiation from the 1986 Chernobyl nuclear incident has impaired tree growth and the health of birds in and around the region of the Ukraine where the disaster took place.

By analyzing the mean growth rates of 105 Scots pine trees located near Chernobyl, the researchers determined that radiation suppressed the growth of the pine trees. The worst effects of the radiation were recorded in the first few years after the nuclear incident, but the surviving trees were left vulnerable to environmental stressors such as drought.

Younger trees were most markedly affected by the radiation, the researchers learned, even decades after the original accident.

Tim Mousseau from the University of South Carolina, conducted the research with Anders Møller of the Université Paris-Sud. In an interview with BBC News, Mousseau said their study was consistent with research done on much smaller sample sizes.

"They are also consistent with the many reports of genetic impacts to these trees," he said.

"Many of the trees show highly abnormal growth forms reflecting the effects of mutations and cell death resulting from radiation exposure."

The study, published in the journal Trees, is one of a trio of papers Mousseau and Møller have recently published on the effects of ionizing radiation on trees and birds in the Chernobyl exclusion zone.

In the journal PlosOne, the researches suggest the fitness of wild birds from Cherobyl suffered from significant rates of cataracts. In Mutation Research, they contend that birds in Chernobyl have high frequencies of tumors and albino feathering.

The research comes at a time when scientists are trying to better understand the effects of the Fukushima nuclear incident that occurred in March 2011, the world's worst nuclear disaster since Chernobyl.

"There's extensive literature from Eastern Europe about the effects of the release of radionuclides in Chernobyl," Mousseau said in a statement. "Unfortunately, very little of it was translated into English, and many of the papers - which were printed on paper, not centrally stored, and never digitized - became very hard to find because many of the publishers went belly up in the 1990s with the economic recession that followed the breakup of the Soviet Union."

In 2006, a World Health Organization forum report suggested that Chernobyl ecosystems are healthy and thriving.

"But when you dug into the Chernobyl Forum report to find out what they based this conclusion on, there were no scientific papers to support it," Mousseau said.

A 2009 summary of Chernobyl research contended that the Chernobyl ecosystem was not as healthy at the 2006 report made it seem.

"But there were some problems -- for example, with the lack of statistical treatment. We're using these studies as a bit of a guide, but trying to do them in a thorough way, better than anyone's done them before," Mousseau said.

"The uniform theme we find from these papers is that, when you look carefully, in a quantitative way, you see numerous biological impacts of low doses of radiation. Not just abundance of animals, but tumors, cataracts, growth suppression."

The researchers hope that their studies will not only shed light on the situation in Chernobyl , but also be of use to people studying the effects of radiation on mainland Japan in the wake of the Fukushima incident.