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

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.