Leaf nutrient concentration, nutrient resorption and litter decomposition in an evergreen broad-leaved forest in eastern China

Abstract

While plant mineral nutrition has been well addressed in temperate ecosystems, our knowledge of this topic in subtropical evergreen broad-leaved forests remains weak. We examined various plant leaf traits and litter decomposition rates among three groups—deciduous species (DB) and evergreen broad-leaved species with leaf life span <1.5 years (EBS) and >1.5 years (EBL) in a secondary evergreen broad-leaved forest in eastern China. Relative to DB, EBS and EBL classes contained 33 and 44% less leaf N, and 28 and 45% less leaf P, respectively. N resorption efficiency varied from 27 to 65%, 21 to 52% and 22 to 51% in DB, EBS and EBL, respectively. P resorption efficiency varied from 38 to 77% in DB, 6 to 58% in EBS and 15 to 55% in EBL. P resorption efficiency was greater in DB than in EBS and EBL while N resorption efficiency did not differ among the three classes. N resorption efficiency was not correlated with either leaf N or N:P ratio. In contrast, P resorption efficiency was positively correlated with leaf P. Litter decomposition rates were 2.45, 1.33 and 2.30 year −1 for DB, EBS and EBL, respectively, but the rates did not significantly differ between groups. Litter decomposition rate was positively correlated with specific leaf area (SLA) and initial litter N but not litter P. In conclusion, there were no significant differences between EBS and EBL for any of the leaf traits measured, but these two classes were different from DB. Plants with long leaf life span tend to minimize nutrient loss more by reducing N concentration in leaf litter than by increasing N resorption efficiency.