Skip to main content
Dryad

Data from: Strategies in Ericaceae to acquire phosphorus in phosphorus-impoverished habitats in the southwest Australian biodiversity hotspot.

Abstract

We hypothesised that some Ericaceae exhibit high leaf manganese (Mn) concentrations [Mn], a proxy for rhizosphere carboxylates, and release root carboxylates. We compared their leaf [Mn] with that of positive and negative reference species, known to release carboxylates or not, respectively. To follow up, we measured the carboxylate-exudation rates of targeted species with high and low leaf [Mn] using seedlings grown in low-P nutrient solutions. Using these complementary approaches, we confirmed that Ericaceae in P-impoverished habitats with high leaf [Mn] exhibit a carboxylate-releasing P-mobilising strategy, like non-mycorrhizal Proteaceae. Surprisingly, some species with low leaf [Mn], which occurred in habitats with high soil pH, also released carboxylates. Therefore, low leaf [Mn] cannot conclusively indicate the absence of carboxylate exudation. These species may release carboxylates along with cations such as potassium or magnesium, which increase the rhizosphere pH, thereby decreasing Mn availability and accumulation in mature leaves. The lack of a significant phylogenetic signal detected for leaf [P] and leaf [Mn] across sampled taxa indicated these nutrient-acquisition traits are not limited to certain clades but likely evolved independently multiple times in Ericaceae. Styphelia sensu lato exhibited the widest trait variation (highest to lowest leaf [P] and [Mn]) of all genera included in this study.