Закономерности изменения дыхания лесной подстилки в градиентах промышленного загрязнения

Abstract

The effect of industrial pollution on the total CO2 emission from the soil surface and the forest litter (measured in situ) in the areas of impact of Middle Ural Copper Smelter (spruce-fir forests) and Karabash Copper Smelter (birch forests) has been studied. Measurements were carried out in the middle of the 2011–2013 growing seasons at 60 plots. Contamination has little influence on the overall CO2 emissions (the difference between the background and impact areas is 1.5– 1.8 times, a significant decrease was observed only at the industrial barren) and has almost no effect on the emission from the forest litter. At the same time, the specific respiratory activity of the litter (respiration of a unit mass of substrate) is closely related to the level of pollution, and the difference between the impact and background areas is substantially greater (3.5–15 times). Comparison of the litter contribution to the total emission of CO2 (30–60 % in coniferous forests, and 17–32 % in hardwood) and the root reserve (7–10 % and 2–5 %, respectively) allows to interpret respiration of litter as being mainly microbial. Stability of carbon dioxide fluxes from the forest litter in a gradient of pollution is due to the interaction of two countervailing processes: reduction of specific respiratory activity of forest litter (due to the inhibition of microorganisms inhabiting it) and the increase of its reserve.