Nature thrives in Chernobyl, scene of the world's most devastating nuclear accident

Chernobyl, the scene of the world's worst nuclear accident, has defied the gloomiest of prophesies by becoming oneof Europe's richest wildlife habitats, teeming with endan-gered species.

Chernobyl, the scene of the world's worst nuclear accident, has defied the gloomiest of prophesies by becoming oneof Europe's richest wildlife habitats, teeming with endan-gered species.

The evacuation of tens of thousands of residents living in the 30km (19-mile) exclusion zone around the Ukrainian reactor has resulted in a flourishing community of plants and animals whose diversity has stunned biologists.

Radioactive fallout from the explosion and fire contaminated 2,800sq km (1,000sq miles) of Ukraine and Belarus, which resulted in the evacuation of 135,000 people and 35,000 cattle and left dozens of towns and villages deserted.

Although the exclusion zone has been subjected to some of the worst radioactive contamination in history, life in all its forms has proved to be remarkably resistant to the known biological effects of radiation, notably mutations and birth deformities.

Scientists studying the site from the International Radioecology Laboratory just outside the zone have reported a startling return of many rare species to the area and a general increase in the diversity of many wild plants and animals.

British biologists involved in the study of the region have called for the zone to become a nature reserve where endangered fauna and flora can be free to breed in what is becoming a pristine habitat.

Arable farmland and pasture has been slowly replaced by weeds and meadows as the land returns to its original forested state.

Large European mammals, such as moose, wild boar, roe and red deer, beavers, wolves, badgers, otters and lynx have become well established within the zone, while species associated with man - such as rats, house mice, sparrowsand pigeons - have declined. Michail Bondarkov, the director of the laboratory, said that 48 endangered species listed in the international Red Book of protected animals and plants are now thriving in the Chernobyl exclusion zone.

Of the 270 species of birds in the area, 180 species are breeding - the rest being migrants that are passing through. Breeding birds include therare green crane, black stork, white-tailed sea eagle and fish hawk.

Freshwater fish, such as carp, pike, roach and perch, are also thriving, Dr Bondarkov said. The scientists have even recorded a rich community of aquatic wildlife living in one of the contaminated cooling ponds at the Chernobyl site.

Asked if there was any evidence that wild animals had suffered long-term declines since the accident or whether the scientists had detected any increase in birth defects, Dr Bondarkov replied: "Such evidence does not exist."

Andrey Arkhipov, the director of the Kiev branch of the International Chernobyl Centre, warned that although wildlife in the zone had become richer through the absence of humans, it was still too early to make a judgement on the region's longer-term future. "The natural recovery of wildlife is really complicated and not very well investigated. Irradiation did result in the death of wildlife but in small, localised places that had really high levels of radiation," Dr Arkhipov said.

Immediately after the 1986 accident, which sent a huge plume of radioactive dust and debris into the atmosphere, relatively small areas within a 3km radius of the plant received massive doses, resulting in the "red forest", where dead pine leaves turned rusty brown.

There were many reports of birth defects and deformities in Ukrainian children and wildlife. Yet a detailed study by an international panel of scientists failed to uncover any evidence that human birth defects were at higher levels than normal, finding a significant increase only in thyroid cancers.

A report on the after-effects, by the Russian Institute of Agricultural Radiology and Agroecology in Obninsk, found that even the most severely damaged areas of the surrounding forest were on their way to a full recovery.

The only long-term effects seem to be beneficial for wildlife and have resulted from the forced depopulation of farms and villages, including the town of Chernobyl itself where 50,000 people once lived. The Russian institute reported: "Some natural populations have thrived as a result of the lack of human interference. No evidence has been found that any plant or animal species have been eliminated from the contaminated areas, except where clean-up activities involving soil removal have drastically altered the ecosystem."

Scientists have detected small biological changes to a limited number of animals and plants, but these do not appear to have had any impact on their ability to survive and breed. One study published in the 1990s allegedly showing high levels of genetic damage to rodents living near Chernobyl was later retracted.

Jim Smith, a radioecologist from the Centre for Ecology and Hydrology in Dorchester, who is monitoring Chernobyl contamination in British sheep, said the latest findings on the exclusion zone were surprising and had demonstrated how important the site has become for understanding ecology.

"We've not really made any hard decisions about what to do with the exclusion zone. I don't think people will live there for decades. I'd like to see something positive done with it, possibly by creating a permanent wildlife reserve," Dr Smith said.

"It is a unique area and we don't really have anywhere like it in western Europe. It would be good to see it protected."