The researchers consider the production of vodka, and its sales profits, a means to aid economic recovery of the communities most adversely affected by the disaster. Radioactive contamination 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. As noted by Baker and Wickliffe, one of many issues is differentiating between negative effects of Chernobyl radiation and effects of changes in farming activities resulting from human evacuation. Near the facility, a dense cloud of radioactive dust killed off a large area of Scots pine trees; the rusty orange color of the dead trees led to the nickname "The Red Forest" (Рудий ліс). The Red Forest was among the world's most radioactive places; to reduce the hazard, the Red Forest was bulldozed and the highly radioactive wood was buried, though the soil continues to emit significant radiation. Other species in the same area, such as birch trees, survived, indicating that plant species may vary considerably in their sensitivity to radiation. Cases of mutant deformity in animals of the zone include partial albinism and other external malformations in swallows 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. Møller is the first author on 9 of the 20 most-cited articles relating to the ecology,