Fig. 1

Species positions along three litter moisture and flammability axes based on principal components analysis (PCA). The first PCA factor (Flam1) explained 44.3% of the variation and was negatively associated with flaming time (r =  − 0.49) and positively associated with consumption (r = 0.47) and saturation moisture content (r = 0.45). The second PCA axis (Flam2) explained 21.4% of the variation and was negatively associated with maximum flame height (r =  − 0.48) and positively associated with time-lag (r = 0.63). The third flammability axis explained 15.8% and was negatively associated with smoldering time (r =  − 0.93). Shared symbol shapes reflect species classified in the same cluster based on a k-means cluster analysis. The gray join plots refer to the relative strength and direction of significant relationships (α = 0.05) between litter traits and moisture/flammability scores. SA:V, surface area-to-volume ratio; SLA, specific leaf area