Exposure to pollutants and productivity of tundra ecosystems

The biomass of Tundra ecosystems gradually increases from 4-7 ton/ha for moss-lichen tundra to 28-29 ton/ha by dry weight for low-bush tundra. In the northern tundra, the plant biomass and dead organic matter are eventually shared. Southwards this percentage tends to diminish, and low-bush living biomass is smaller than dead plant remains mass. A typical feature of the Tundra ecosystems plant species is the prevalence of underground matter (roots) up to 70-80% of the total biomass. 

The average mass distribution of Tundra ecosystems is as shown in Table 7. 

The biogeochemical turnover of nitrogen is about 50 kg/ha per year. A similar value was shown for the turnover of total mineral elements, 47 kg/ha/yr. The relevant values for various trace and macroelements are shown in Table 8. 

Chemical species Chemical species symbol Plant uptake fluxes, kg/ha/yr 

The flux of chemical elements per unit area in tundra ecosystems is not proportional to the plant uptake. Presumably, some elements, like Zn and Cu, are taken up selectively, whereas other trace elements, like Ti, Zr, V, or Y, are absorbed passively, depending on their content in the environmental media. 

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