Environmental drivers of microbial community composition in a temperate forest

Recently, much attention has been focused on the importance of forests to the global carbon cycle. Microorganisms are a critical component of the carbon cycle in forests, participating in important ecosystem processes and degrading various carbon compounds, from simple to highly recalcitrant compounds. However, most studies in this regard have focused on fungi. Only in recent years has it become known that bacteria are also capable of degrading complex plant polymers in soil, and that their contribution to the carbon cycle may be as important as that of fungi. Furthermore, our knowledge of the temporal dynamics of both fungal and bacterial communities is limited, as well as their response to different environmental drivers. The main objective of this dissertation was to fill these knowledge gaps by (1) quantifying the rate of temporal turnover of fungal and bacterial communities in soils of temperate forests, (2) describing the factors that shape fungal communities in spruce and beech stands during their long-term development (stand age), (3) assessing the contribution of fungi and bacteria to the utilisation of different carbon sources in forest soils, and finally (4) describing the development of bacterial communities in response to clearcutting of a spruce stand. The study of microbes..