Spatial and temporal variability of soil microbial community in the Carpathian biosphere reserve

Abstract

Abstract In this study, the effect of endogenous and exogenous factors on the soil microbiome in the primitive forest ecosystems of the Carpathian Biosphere Reserve (Shyrokoluzhansky massif) in Ukraine was been investigated as temporal variation. These unique ecosystems have a model value for investigating the distinctive soil microbiota, such as the structure of their microbial communities, the number of major ecological groups, and their spatial variability. For this aim, microbial communities in the soil were been researched in the years 2008 and 2018 by field sampling, and georeferenced field data has been collected for mapping process in geographic information systems (GIS). Microbiological studies on soils in the research area were been carried out according to the general methods used in soil microbiology. Spatial distribution of microbial communities was been transformed to interpolated raster maps for the years 2008 and 2018 by utilizing Kriging interpolation method in GIS. The relationships of soil microbial communities with elevation, climate, and soil variables were also investigated by utilizing available climate (annual mean temperature and annual precipitation amount), elevation, and soil (sand-silt-clay, organic matter, pH, and cation exchange capacity) raster maps. Statistical analyses were been conducted by utilizing test of normality (Shapiro–Wilks), descriptive statistics, t-test, correlation, and linear regression analyses. Significant increases in the number of microorganism communities were been detected from 2008 to 2018, with the most significant increases seen in oligotrophs and pedotrophs, followed by ammonifiers and bacteria. While ammonifiers and bacteria constituted the first group similar to each other in terms of the number of microorganisms, the second group was been formed by pedotrophs and oligotrophs. The differences between these two groups of microorganisms also reflected in their relationships with the independent variables. The strongest associations with microorganism communities were been found between elevation, Cation Exchange Capacity (CEC), precipitation and temperature variables. While ammonifiers and bacteria showed a negative relationship with elevation, CEC and precipitation, and a positive relationship with temperature, pedotrophs and oligotrophs showed a positive relationship with altitude, CEC and precipitation and a negative relationship with temperature. Strong relationships were been modeled. Temperature and precipitation values also increased significantly between 2008 and 2018, giving some clues about how global warming affects the geographical distribution of microorganism communities. *Corresponding author. E-mail Addres: kenankilic@ohu.edu.tr