Nutrient resorption of leaves and roots coordinates with root nutrient-acquisition strategies in a temperate forest

Abstract

• Nutrient acquisition, conservation and recycling are three mechanisms for plants to meet their nutritional requirements. However, how nutrient recycling relates to other mechanisms remains unknown. Here, we hypothesize that nutrient resorption processes are coordinated with plant nutrient-acquisition strategies.
• We measured leaf and root nutrient resorption efficiencies and proficiencies and root economic traits for 34 coexisting ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) temperate woody species.
• Our results revealed that species with lower foraging efficiency relying on mycorrhizal fungi for nutrient absorption (e.g. larger root diameter) have higher root phosphorus resorption efficiency and greater phosphorus concentrations of senesced roots, while species with conservative nutrient-acquisition strategies (e.g. higher root tissue density) have lower nitrogen and phosphorus concentrations of senesced leaves and roots.
• Overall, our results demonstrate that plant nutrient acquisition and protection strategies are partly coordinated with plants' ability to resorb nutrients. First, they suggest that outsourcing phosphorus acquisition to mycorrhiza may limit the value for plants to reduce phosphorus loss. Second, those species better able to protect their living leaves and roots from adversity are not necessarily the most efficient to recycle nutrients, but are nonetheless the most capable of minimizing nutrient loss during organ senescence.