Soil fungal community structure in a temperate upland grassland soil.

Abstract Alterations in soil microfungal community structure across a transect between a semi-natural upland grassland and an agriculturally improved enclosure were assessed using an indirect measurement of active fungal biomass (ergosterol), together with a nucleic acid approach, terminal restriction fragment length polymorphism (TRFLP), which was compared to a commonly used but less sensitive community fingerprinting technique, denaturing gradient gel electrophoresis (DGGE). These techniques indicated that there was no reduction in numbers of fungal ribotypes across the floristic transect, despite decreased floristic diversity and a reduction of more than two-fold in ergosterol concentration. Although there were no differences in ribotype number, there was a decrease in diversity and an increase in dominance in only one of the transitional areas. The highest degree of variability within fungal communities was also found in this transitional area, with 84% of ribotypes only being detected in one of three replicates. Comparison of the two fungal community fingerprinting approaches indicated that TRFLP (26-33 ribotypes) was more sensitive for monitoring alterations in fungal community structure than DGGE (13-18 ribotypes). Using a measurement of the relative percentage of each ribotype within communities, a decrease in abundance of prominent ribotypes of the natural grassland soil fungal community was indicated together with an emergence of previously undetected ribotypes towards the improved area. This may have important implications for ecosystem stability or productivity, particularly if agricultural inputs to managed grasslands are suspended.