Pathways for the effects of increased nitrogen deposition on fauna

Although all identified pathways and bottlenecks are supported by peer reviewed literature, we conclude that scientific evidence on the causal relationship between increased N deposition and effects on fauna in the complete causal chain is still insufficient. We recommend that future research should aim to clarify the causal mechanisms underlying the observed changes in species composition attributed to N deposition. The most severe gaps in knowledge concern subtle changes in plant chemistry and changes in availability of prey and host species to higher trophic levels.