The role of fungi and bacteria in the mineralization of nitrogen compounds in the soil of low-productivity birch forest of the southern taiga subzone of European Russia
S. M. RAZGULIN1, N. I. KOPYTINA2,3
1Institute of Forest Science Russian Academy of Sciences, Uspenskoe, Russia
2Papanin Institute for Biology of Inland Waters Russian Academy of Sciences, Borok, Russia
3A. O. Kovalevsky Institute of Biology of the Southern Seas of the Russian Academy of Sciences, Sevastopol, Russia
Keywords: saprotrophic fungi, bacteria, soil biogeochemical parameters, net ammonification, inhibitor analysis
Abstract
The dynamics of the abundance and distribution patterns of mycelial fungi, yeasts and bacteria were studied in the soil of a bilberry-sphagnum birch forest in the Yaroslavl region, taking into account the biogeochemical background, and the contribution of fungi and bacteria to the net ammonification process was determined using inhibitor analysis. Bacteria were predominant in the birch forest soil (43.5-98.7 %), while the mycobiota included fungi of the genus Penicillium (1-80 %) and yeast (0-88 %). A relationship was established between the abundance of all groups of microorganisms and pH; mycelial fungi with the content of Corg and NН+4, the C/N ratio and C-CO2 emission; yeast with soil moisture. The dynamics of the numbers of fungi, yeasts and bacteria in the upper soil horizon were close and negatively correlated with seasonal changes in ammonification ( r = -0.86 - -0.97). In the At1 horizon, the contribution of fungi to ammonification prevailed over bacteria, 208 ± 5 and 121 ± 3 mg N/100 g. In the peaty layer (At2 horizon), a slight predominance of fungal activity over bacteria was noted 98 ± 4 and 72 ± 4 mg N/100 g. In the eluvial part of the profile (A2 horizon), a similar contribution of these groups was obtained 8.7 ± 0.4 and 9.7 ± 0.5 mg N/100 g.
|
