Plant and soil microbe responses to light, warming and nitrogen addition in a temperate forest

1. Temperate forests across Europe and eastern North America have become denser since the 1950s due to less intensive forest management and global environmental changes such as nitrogen deposition and climate warming. Denser tree canopies result in lower light availability at the forest floor. This shade may buffer the effects of nitrogen deposition and climate warming on understorey plant communities. 2. We conducted an innovative in-situ field experiment to study the responses of co-occurring soil microbial and understorey plant communities to nitrogen addition, enhanced light availability, and experimental warming in a full-factorial design. 3. We determined the effects of multiple environmental drivers and their interactions on the soil microbial and understorey plant communities, and assessed to what extent the soil microbial and understorey plant communities co-vary. 4. High light led to lower biomass of the soil microbes (analysed by phospholipid fatty acids), but the soil microb...