Linking seed size and number to trait syndromes in trees

Aim Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits are closely linked to fitness. We tested whether link between and seed number size is consistent with two hypotheses, termed leaf economics spectrum plant syndrome, or reproduction represents an independent dimension related a size–seed trade-off. Location Most data come Europe, North Central America East Asia. A minority South America, Africa Australia. Time period 1960–2022. Major taxa studied Trees. Methods gathered 12 million observations seeds produced in 784 tree species. estimated by individual trees scaled it up species level. Next, we used principal components analysis generalized joint attribute modelling (GJAM) map on spectrum. Results Incorporating into trait while controlling for environment phylogeny GJAM exposes relationships might otherwise remain hidden. Production large total biomass [product size; hereafter, productivity (SSP)] associated high area, low foliar nitrogen, specific area (SLA) dense wood. numbers small nutrient-demanding softwood, leaves SLA. Trait covariation opposing strategies: one fast-growing, early successional, dispersal, other slow-growing, stress-tolerant, recruit shaded conditions. Main conclusions Earth system models currently assume reproductive allocation indifferent among functional types. Easily measurable strong predictor productivity. The connection SSP form first basis improved fecundity prediction across global forests.