The reaction of algo-cyanobacterial complexes on increasing concentration of copper ions in soil under different agricultural crops
Studying the influence of increasing concentration of copper ions (3, 150, 300 mg/kg) on algo-cyanobacterial complexes in soil under crops of wheat, mustard and peas has shown change in quantitative and structural indices of these complexes. Under all cultures a high degree of negative correlative dependence between the doses of copper ions and the number of eukaryotic green algae and seaweed diatoms is revealed (with correlation coefficients from -0.5150 to -0.9977). The increasing concentration of copper also has a negative effect on development of prokaryotic phototrophs (cyanobacteria) under crops of mustard and peas (with correlation coefficients from -0.9614 to -0.9738). At the same time the increasing concentration of copper practically doesn't influence the development of cyanobacterial complexes under wheat crops (coefficient of correlation -0.0090). Fluctuations of the amount of algae and cyanobacteria in soil under the influence of copper ions lead to change in algo-cyanobacterial population structure of complexes. As a rule, technogenic influence leads to the effect of cyanofitization which is shown in increase of the share of cyanobacteria in phototrophic structure of the populations under the influence of various pollutants. Here the effect of cyanofitization of algo-cyanobacterial complexes is observed only in the option with introduction of copper ions increasing concentration under wheat, where the contribution of cyanobacteria to the structure of phototrophic complexes increases from 66.9% in control to 87.3% (Cu<sup>2</sup> + 300 mg/kg). Thus in agroecosystems a certain impact is made by higher plants on the development of phototrophic microbial groups owing to certain features of root system development and of carrying out nutrients from soil and allocated exometabolites which is shown in intensity of algae and cyanobacteria reproduction in soil under various cultures.