Contrasting phosphorus‐impoverished habitats influence the species‐dependent phosphorus‐acquisition strategies of plants

Abstract Plant species in phosphorus (P)‐impoverished habitats express diverse P‐acquisition strategies. However, the effect of soil P concentration ([P]) on the expression of specific P‐acquisition strategies and whether these strategies have converged within families remains unknown. We investigated the P‐acquisition traits of 12 coexisting species from Proteaceae, Fabaceae, Myrtaceae and Ericaceae, including root carboxylate exudation, in two contrasting habitats and assessed soil [P] in the rhizosphere and bulk soil. The soils in these contrasting habitats differed in depth, volumetric water content and total [P]. Each species exhibited a distinct P‐acquisition strategy, with limited convergence within its respective family. The P‐acquisition strategies expressed were associated with bulk soil [P]. Notably, soil total [P] and organic [P] strongly affected leaf manganese concentration, a proxy for rhizosphere carboxylates. In P‐impoverished habitats, species expressed multiple P‐acquisition strategies, including carboxylate and phosphatase exudation and facilitation by P‐mobilising plants, reflecting their taxonomic background and bulk soil [P]. This study highlights how contrasting habitats with different soil [P] influenced P‐acquisition strategies and demonstrates the variation in P‐acquisition strategies among species in severely P‐impoverished environments. These findings contribute to a deeper understanding of how plants obtain P to allow their coexistence in extremely P‐limited landscapes. Read the free Plain Language Summary for this article on the Journal blog.