The territory of the zone is polluted unevenly. Spots of hyperintensive pollution were created first by wind and rain spreading radioactive dust at the time of the accident, and subsequently by numerous burial sites for various material and equipment used in decontamination. Zone authorities pay attention to protecting such spots from tourists, scrap hunters, and wildfires, but admit that some dangerous burial sites remain unmapped, and only recorded in the memories of the (aging)
Chernobyl liquidators.
Flora and fauna There has been an ongoing scientific debate about the extent to which
flora and
fauna of the zone were affected by the radioactive contamination that followed the accident. Other species in the same area, such as
birch trees, survived, indicating that plant species may vary considerably in their sensitivity to radiation. and insect mutations. A study of several hundred birds belonging to 48 different species also demonstrated that birds inhabiting highly radioactively contaminated areas had smaller brains compared to birds from clean areas. A reduction in the density and the abundance of animals in highly radioactively contaminated areas has been reported for several
taxa, including birds, insects, spiders, and mammals. In birds, which are an efficient
bioindicator, a negative correlation has been reported between background radiation and bird species richness. Scientists such as Anders Pape Møller (
University of Paris-Sud) and Timothy Mousseau (
University of South Carolina) report that birds and smaller animals such as
voles may be particularly affected by radioactivity. However, some of Møller's research has been criticized as flawed. Prior to his work at Chernobyl, Møller was accused of falsifying data in a 1998 paper about asymmetry in oak leaves, which he retracted in 2001. In 2004, the
Danish Committees on Scientific Dishonesty (DCSD) reported that Møller was guilty of "scientific dishonesty". The
French National Centre for Scientific Research (CNRS) subsequently concluded that there was insufficient evidence to establish either guilt or innocence. Strongly held opinions about Møller and his work have contributed to the difficulty of reaching a scientific consensus on the effects of radiation on wildlife in the Exclusion Zone. More recently, the populations of large mammals have increased due to a significant reduction of human interference. The populations of traditional
Polesian animals (such as the
gray wolf,
badger,
wild boar,
roe deer,
white-tailed eagle,
black stork,
western marsh harrier,
short-eared owl,
red deer,
moose,
great egret,
whooper swan,
least weasel,
common kestrel, and
beaver) have multiplied enormously and begun expanding outside the zone. The zone is considered as a classic example of an
involuntary park. The return of wolves and other animals to the area is being studied by scientists such as Marina Shkvyria (
National Academy of Sciences of Ukraine), Sergey Gaschak (Chernobyl Centre in Ukraine), and Jim Beasley (
University of Georgia).
Camera traps have been installed and are used to record the presence of species. Studies of wolves, which are concentrated in higher-radiation areas near the center of the exclusion zone, may enable researchers to better assess relationships between radiation levels, animal health, and population dynamics. Special
game warden units are organized to protect and control them. No scientific study has been conducted on the population dynamics of these species. The rivers and lakes of the zone pose a significant threat of spreading polluted
silt during spring floods. They are systematically secured by
dikes.
Grass and forest fires It is known that fires can make contamination mobile again. In particular, V.I. Yoschenko
et al. reported on the possibility of increased mobility of
caesium,
strontium, and plutonium due to
grass and
forest fires. As an experiment, fires were set and the levels of the radioactivity in the air downwind of these fires were measured. Grass and forest fires have happened inside the contaminated zone, releasing
radioactive fallout into the atmosphere. In 1986, a series of fires destroyed of forest, and several other fires have since burned within the zone. A serious fire in early May 1992 affected of land, including of forest. This resulted in a great increase in the levels of caesium-137 in airborne dust. In 2010,
a series of wildfires affected contaminated areas, specifically the surroundings of
Bryansk and border regions with Belarus and
Ukraine. The Russian government claimed that there was no discernible increase in radiation levels, while
Greenpeace accused the government of denial.
Current state of the ecosystem Despite the negative effect of the disaster on human life, many scientists see an overall beneficial effect to the
ecosystem. Though the immediate effects of the accident were negative, the area quickly recovered and is today seen as very healthy. The lack of people in the area has increased the
biodiversity of the Exclusion Zone in the years since the disaster. In the aftermath of the disaster, radioactive contamination in the air had a decidedly negative effect on the fauna, vegetation, rivers, lakes, and groundwater of the area. The radiation resulted in deaths among coniferous plants, soil invertebrates, and mammals, as well as a decline in reproductive numbers among both plants and animals. The surrounding forest was covered in radioactive particles, resulting in the death of 400 hectares of the most immediate pine trees, though radiation damage can be found in an area of tens of thousands of hectares. An additional concern is that as the dead trees in the Red Forest (named for the color of the dead pines) decay, contamination is leaking into the groundwater. Despite all this, Professor Nick Beresford, an expert on Chernobyl and ecology, said that "the overall effect was positive" for the wildlife in the area. The impact of radiation on individual animals has not been studied, but cameras in the area have captured evidence of a resurgence of the mammalian population – including rare animals such as the
lynx and the vulnerable European bison. Research on the health of Chernobyl's wildlife is ongoing, and there is concern that the wildlife still suffers from some of the negative effects of the radiation exposure. Though it will be years before researchers collect the necessary data to fully understand the effects, for now, the area is essentially one of Europe's largest
nature preserves. Overall, an assessment by
plant biochemist Stuart Thompson concluded, "the burden brought by radiation at Chernobyl is less severe than the benefits reaped from humans leaving the area." In fact, the ecosystem around the power plant "supports more life than before". ==Infrastructure==