The initially high doses in the pine forests surrounding Chernobyl led to the “Red Forest" Pine trees are particularly sensitive to radiation and many trees died, giving a rusty appearance in the needles as they die, hence the name. This is the same color that is widespread over the northern Rocky Mountains as the pine trees are killed by mountain pine beetle, in part as a consequence of global warming. However, the severe consequences in the forests around Chernobyl were not long-lived. Trees grew back as the high radiation levels dropped quickly in the first few months after the accident. Pripyat was abandoned by the people and it is turning into a forest. Fields quickly reverted to grasslands and trees as a more natural ecosystem developed in the exclusion zone. 137Cs activity has remained high in berries, mushrooms, and wild game in the forests of the exclu­sion zone, which precludes their use as food, though some illegal gathering and poaching occur.

In spite of the elevated radioactivity, the exclusion zone has become a wildlife preserve half the size of Yellowstone National Park where birds and mammals thrive (20, 30). Between 250 and 280 bird species—40 of them rare or endan­gered, including white-tailed eagles and black storks—have been sighted in the area. Large mammals that thrive include boars, red deer (elk), roe deer, European bison, moose, wolves, foxes, beavers, and Przewalski’s horses. The only subspe­cies of wild horse that was brought back from the cusp of extinction, Przewalski’s horses were introduced into the exclusion zone in a controversial move. Thirty-one horses were released in 1998 and 1999, though 10 of them soon died—not from radiation but from the stress caused during transport. By December 2003 they had grown to 65 head (16). Unfortunately, the numbers are now down to as little as 30-40 as poachers have begun killing some of the horses (31).

The Soviet Union had cleared the forest around Chernobyl and built canals to drain the marshy land so that it could be turned into collective farms. After the nuclear accident, beavers returned to their natural habitat as people abandoned the exclusion zone and soon transformed the farmland back to its native marsh­land. Vast flocks of waterfowl migrate through and spend months in the water­ways. Huge catfish up to 18 feet long swim in the former artificial lake that was used to cool the reactors. Their size is not because they are mutants but because they live up to 100 years and there are no top predators to kill them, so they just keep growing. Around 120 wolves in numerous packs thrive as top predators to keep the populations of bison, deer, elk, and moose in balance (32). As it turns out, nature thrives in the absence of people—radiation is less of a problem than people!

Mary Mycio, the author of the excellent book Wormwood Forest: A Natural History of Chernobyl (2005), put it very well.

It seems odd, but it is impossible to smell fresher air in an inhabited urban setting than in Chornobyl,4 where the number of cars can usually be counted on one hand and songbirds frequently provide the only sound. It is one of the disaster’s paradoxes, but the zone’s evacuation put an end to industri­alization, deforestation, cultivation, and other human intrusions, mak­ing it one of Ukraine’s environmentally cleanest regions—except for the radioactivity. (31)

Agriculture was affected by radioactivity, but the levels decayed rapidly. Over time, the transfer of 1 37Cs from soil into plants became the biggest problem with radioactivity in crops, but this was reduced through weathering, physical decay, binding in the soils, and remediation efforts. Levels of 137Cs are now below national and international standards in agricultural food products produced in areas contaminated by radiation from Chernobyl, with the exception of the exclu­sion zone, where agriculture is banned (20). The Belarus government is beginning a program to resettle thousands of people in the formerly contaminated areas and to return the areas to normal use with few restrictions, though some areas with too much radioactivity will be reforested and managed (13).

A relatively small area in northern Wales, Scotland, and Cumbria was unfor­tunately under the radioactive plume when it rained heavily, bringing down high concentrations of 1 37Cs onto the peaty soils where sheep grazed. About 9,700 farms were unable to sell their sheep because internal radioactivity from 137Cs exceeded 1,000 Bq per kilogram—the international standard for restricting meat from consumption. Because the peaty soils kept the cesium in the plants rather than being adsorbed into the soils, the area maintained high levels of cesium for decades. It wasn’t until 2010 that the Scottish farmers were able to raise and sell sheep without quarantine (33, 34).