Coordination of leaf and stem traits in 25 species of Fagaceae from three biomes of East Asia

Abstract

It has been debated whether leaf and stem economics spectra are coordinated across species, because previous studies have provided contradictory results. These studies have been restricted to single biomes, and we hypothesize that climate seasonality may determine the strength of coordination between leaf and stem trait combinations. Herein, using 25 Fagaceae species from East Asia, we investigated the coordination of 16 leaf traits and 5 stem traits across and within three biomes (cool temperate, warm temperate, and tropical forests). The traits were chosen to reflect multiple aspects of plant adaptive strategies, such as water, carbon, and nutrient use. The leaf and stem traits of species that reflect resource-use strategies for different resources were functionally coordinated, forming a single axis of trait variation across biomes. This axis represents the trade-off between fast and slow resource-use strategies. We found the trend that the coordination between leaf and stem traits was the strongest in cool temperate forests after removing two Fagus species, followed by warm temperate forests, but was not observed in tropical forests. Our results support the proposed model that plants vary from slow to fast resource exploitation, using closely related species, and suggest that temperature modulates the coordination of leaf and stem economics spectra.