Fig. 2From: Importance of overstorey attributes for understorey litter production and nutrient cycling in European forestsAmount of overstorey foliar litterfall (target tree species) and understorey non-lignified biomass per area unit across the studied forest types. Bars represent the mean ± standard error of the mean. Letters above the bars denote significant differences across forest types, for overstorey (uppercase) and understorey (lowercase) variablesBack to article page