The Bioelemental Blueprint of Hygrophytic Bryophytes: Linking Composition to Function

Chemical elements, as the fundamental components of matter constituting living organisms, play critical roles in physiological processes and metabolic pathways, directly influencing how organisms interact with each other and adapt to their environments. However, in bryophytes, the link between traits and elements beyond C, N and P is mostly unknown. By analysing a large set of traits in bryophytes, we here explore the connection between bioelemental and other functional traits and assess their performance in differentiating bryophyte lineages (mosses and liverworts) and growth forms. We demonstrate that the elemental composition of bryophytes outperforms metabolic traits (e.g., photosynthetic capacity, dark respiration, BVOCs [biogenic volatile organic compounds] emissions) or morphological traits (e.g., cell length and width) in distinguishing bryophyte lineages (mosses and liverworts) and growth forms. Concentrations of key elements such as B, Cu, C, Na, K, S, and N isotope ratio δ¹⁵N played pivotal roles in separating these groups. Additionally, we identified significant correlations between specific elements and functional traits: C, N, P, S, Mg, and Zn were strongly linked to photosynthetic activity, while B, Cr, Fe, and Mn were associated with the production of BVOCs. This study supports and expands the elemental ecology framework, emphasizing the potential of species' bioelemental signatures as a powerful tool for understanding their ecological functioning.