Early positive biodiversity effects on total biomass in experimental tree seedling assemblages with and without water limitation

Questions While positive effects of tree diversity on community biomass have often been reported in mature stands, the debate whether may be detectable at seedling level persists, with opposing outcomes found so far. We still lack a comprehensive evaluation biodiversity (so-called ‘complementarity’ and ‘selection’ effects), as well phenotypic drivers play, underlying early-community biomass. Even less is known about such change under water-limited conditions. Location Seeds from four species coexisting Mediterranean forest (Spain). Methods built experimental assemblages three levels — monocultures, two-species four-species mixtures two soil moisture quantified extent to which richness, identity, community-weighted mean (CWM) functional dissimilarity (FD) influence complementarity selection effects. computed CWM FD for seven traits related water light acquisition; we calculated above- below-ground measures level. Results Our results showed that drove greater more diverse stage. This pattern was largely favored by particular species, Quercus faginea, distinct (great height, lateral ramification root high dry matter content), induced effect Moreover, our study deficit limited production above-ground without interacting community’s richness. Conclusion provides evidence occur early, stage, it highlights essential role certain play their initial development stages favoring spatial resource partitioning. work motivates future studies apply integrated approaches assessing both community-wide species-specific understand biodiversity–biomass relationship.