Leaf phosphorus fractions vary with leaf economic traits among 35 Australian woody species

Abstract

Summary Adaptations of plants to phosphorus (P) deficiency include reduced investment of leaf P in storage (orthophosphates in vacuoles), nucleic acids and membrane lipids. Yet, it is unclear how these adaptations are associated with plant ecological strategies. Five leaf P fractions (orthophosphate P, Pi; metabolite P, PM; nucleic acid P, PN; lipid P, PL; and residual P, PR) were analysed alongside leaf economic traits among 35 Australian woody species from three habitats: one a high‐P basalt‐derived soil and two low‐P sandstone‐derived soils, one undisturbed and one disturbed by human activities with artificial P inputs. Species at the undisturbed low‐P site generally exhibited lower concentrations of total leaf P ([Ptotal]), primarily associated with lower concentrations of Pi, and PN. The relative allocation of P to each fraction varied little among sites, except that higher PL per [Ptotal] (rPL) was recorded at the undisturbed low‐P site than at the high‐P site. This higher rPL, reflecting relative allocation to membranes, was primarily associated with lower concentrations of leaf nitrogen at the undisturbed low‐P site than at the high‐P site. Associations between leaf P fractions and leaf nitrogen may provide a basis for understanding the variation in plant ecological strategies dependent on soil P availability.