Taiga fire on Bolshoy Ushkany Island as a model case of forest soil transformation and potential source of eutrophication in Lake Baikal coastal zone


  • Vashukevich, N.V. 1
  • Timoshkin, O.A. 2
  • Samsonov, D.P. 3
  • Kulikova, N.N. 2
  • Levasheva, M.V. 4
  • Lukhnev, A.G. 2
  • 1 Ural State Agrarian University, 42 Karl Liebknecht Str., Ekaterinburg, 620075, Russia
    2 Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk, 664033, Russia
    3 Research and Production Association (RPA) “Typhoon” Roshydromet, 4 Pobedy Str., Obninsk, 249038, Russia
    4 Irkutsk State University, 1 Karl Marks Str., Irkutsk, 664025, Russia




taiga fires, pyrogenic soils, nutrients, polycyclic aromatic hydrocarbons, retene, Baikal, coastal zone eutrophication


The soils of a model site in Severnaya Bay, affected by fire in June 2015, on Bolshoy Ushkany Island (Lake Baikal) were studied. About 70% of the Island taiga burned. The bloom of cyanoprokaryotes in the coastal zone and their massive wash-ups were observed in this bay a year later, in summer 2016. When studying the soils at two points of observation (a high and a low-intensity fire), we focused on geochemically congugated soil profiles. Wildfire strongly affected top soil horizons (4−5 cm), entailing changes in charred roots biomass, soot, charcoal and structural aggregate stability. Migration and accumulation of total organic carbon (30−35 mg/g), N-NH4 (40 mg/kg), phosphates (104 mg/kg) detected at the foot of the slope, were 1.5−3 times higher than the content of these elements in the unburned soil. The slope migration of pyrogenic carbon was traced studying polycyclic aromatic hydrocarbons (PAHs). Retene, a marker of wood combustion, comprised 80-90% of PAHs. In the upper part of the slope, PAH was 270 ng/g, in the transit position − 47 ng/g. In the lower part, due to the accumulation of pyrogenic organic compounds, the content of PAH increased to 100 ng/g. Post-pyrogenic slope erosion was detected a year after the fire in Severnaya Bay. Biogenic migration and accumulation in the beach area (including interstitial water) can have consequences as a potential factor in the eutrophication of Lake Baikal coastal zone.


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