Some soil properties and microbial biomass of Pinus maritima, Pinus pinea and Eucalyptus camaldulensis from the Eastern Mediterranean coasts

Background: Salt-affected soils occupy wide areas that have ecological importance in semi-arid and arid regions. Excessive amounts of salt have adverse effects on soil physical and chemical properties and also on the microbiological processes. The soils of Pinus maritima, Pinus pinea, and Eucalyptus camaldulensis were found to be under salinity stress in the present study area. Thus, the carbon, nitrogen, phosphorus contents, microbial biomass, and carbon mineralization were determined in the soils sampled from the Tarsus-Karabucak Forest of the Eastern Mediterranean Region (Turkey). Method: Carbon mineralization of all samples was measured by the CO2 respiration method over 30 d at 28°C and constant moisture. Results: There were no significant differences in the carbon mineralization among the soils. The average fungi count in 1 g of air dried soils of P. maritima, P. pinea, and E. camaldulensis were found to be a 72000 colony forming unit (cfu)/g, 25300 cfu/g, and 28500 cfu/g, respectively. The total bacterial counts were 4x103 cfu/g, 10x103 cfu/g, and 7x103 cfu/g and the counts of anaerobic bacteria were 17800 cfu/g, 42900 cfu/g, and 27300 cfu/g, respectively. Conclusions: It is possible to conclude that salt, as an ecological factor, had no effect on microbial activity. This may be as a result of heavy rains which decreased the salt concentrations of the soil in the sampling region.