Inferring community assembly processes from functional seed trait variation along elevation gradient

Assembly of plant communities has long been scrutinized through the lens trait-based ecology. Studies generally analyse functional traits related to vegetative growth, survival and resource acquisition thus ignore how assembly rules may affect plants at other stages their life cycle, particularly when seeds disperse, persist in soil germinate. Here, we analysed an extensive dataset 16 for 167 species measured in-situ 36 grasslands located along elevation gradient studied impact abiotic filtering, biotic interactions dispersal on reflecting different trait categories: germination, seed morphology. For each community, quantified community-weighted means (CWMs) diversity (FD) all established relationships mean annual temperature. The were weakly correlated with traits. Therefore, these constituted independent axes phenotypical variation that could be affected differently by community rules. Abiotic filtering impacted mostly a lesser extent germination morphological Increasing low-temperature stress upland sites selected short-stature, slow-growing frost-tolerant produce small quantities high degree dormancy, temperature requirements low speed. Biotic interactions, specifically competition lowlands facilitation uplands, also filtered some communities. benign climate seems promote competitive strategies include fast growth (vegetative traits) early (germination traits), whereas effects cancelled out strong filtering. changes main vector from zoochory anemochory strongly structure This explained stronger vertical turbulence moderate warm upwinds grazing intensity uplands select light non-round shaped lower terminal velocity endozoochorous potential. Synthesis. We demonstrate that, addition traits, can substantially contribute structuring environmental gradients. Thus, ‘hard’ are critical detect multiple, complex Consequently, such should included core lists and, applicable, incorporated into analysis assembly.