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

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.

To test our hypothesis that some Ericaceae exhibit high leaf
manganese concentrations [Mn], a proxy for rhizosphere carboxylates, and
release root carboxylates, we collected fully expanded mature leaves of 32
Ericaceae in southwest Australia from October 2020 to July 2022. We also
collected leaves of positive reference species (Proteaceae)
and negative reference species
(Xanthorrhoeaceae) at most sample
locations. When there was no Xanthorrhoea species
nearby, we used young expanding leaves of the target species as a negative
reference. Total mature leaves [Mn] (Figure 2) and [P] (Figure 3) were
oven-dried leaf samples and ground to a fine powder. The acid was digested
and analysed by ICP-OES. Leaf [Mn] was compared using
the Welch t-test to assess the difference in mean concentrations between
the negative reference and target species. Differences in leaf [Mn] and
[P] across species were analysed using one-way ANOVA, and followed by
Tukey-Kramer’s HSD post-hoc tests at
P < 0.05. To measure root
carboxylate exudation, we grew seedlings of Ericaceae in a
controlled-environment glasshouse at the University of Western Australia
at 18/25℃ (night/day) temperatures. After approximately 20 weeks in the
nutrient solution, root exudates were collected from excised parts of root
systems. Total effective carboxylate is calculated by summing up the
concentrations the sum of all di- and tri-carboxylates, with mainly
citrate, malate, and oxalate. All carboxylate concentrations are expressed
per unit root fresh weight. Our results showed that all the selected plant
species, which exhibited either relatively high or low leaf [Mn], all
released carboxylates when grown in low-P nutrient solution (Figure
5).

# Data from: Strategies in Ericaceae to acquire phosphorus in
phosphorus-impoverished habitats in the southwest Australian biodiversity
hotspot. Dataset DOI: [10.5061/dryad.9w0vt4btf](10.5061/dryad.9w0vt4btf)
## Description of the data and file structure For ericoid mycorrhizal
Ericaceae, a prominent and diverse family in southwest Australia, it is
unclear whether they release carboxylates as a P-acquisition strategy. We
hypothesised that some Ericaceae exhibit high leaf manganese (Mn)
concentrations [Mn], a proxy for rhizosphere carboxylates, and release
root carboxylates. #### File:
Figure_2_(leaf_manganese_concentrations_were_separated_into_each_sanple_area_).xlsx **Description:**  We collected fully expanded mature leaves of 32 Ericaceae in southwest Australia, to analyse their leaf manganese concentration ([Mn]), they were oven-dried leaf samples and ground to a fine powder, then acid digested analysed by ICP-OES. Leaf [Mn] was compared using the Welch t-test to assess the difference in mean concentrations between the negative reference and target species. Our results: Some Ericaceae species exhibited a leaf [Mn] close to or even higher than that of the positive reference. ##### Variables * Species names: the names of 32 species of Ericaceae in southwest Australia. * Mn (mg kg-1): mature leaf manganese concentrations in dry weight. #### File: Figure_3_(leaf_phosphorus_conrentrations).xlsx **Description:** We collected fully expanded mature leaves of 32 Ericaceae in southwest Australia, to analyse their leaf phosphorus concentration ([P]), they were oven-dried leaf samples and ground to a fine powder, then acid digested analysed by ICP-OES. Differences in leaf[P] across species were analysed using one-way ANOVA, and followed by Tukey-Kramer’s HSD post-hoc tests at *P* < 0.05. Our results showed that Species with the highest leaf [Mn] did not have the highest leaf [P]. ##### Variables * Species names: the names of 32 species of Ericaceae  in southwest Australia. * P (mg g-1):  mature leaf phosphorus concentrations in dry weight. #### File: Figure_4_(leaf_manganese_concentration_and_phosphorus_concentration_for_each_species).csv **Description:**  We used Standardised Major Axis regression (SMA) to examine the correlation between leaf [Mn] and leaf [P] of targeted Ericaceae species in their low-P natural habitats. ##### Variables * Species names: the names of 32 species of Ericaceae  in southwest Australia. * Mn (mg kg-1): Mn (mg kg-1): mature leaf manganese concentrations in dry weight. * P (mg g-1): mature leaf phosphorus concentrations in dry weight. #### File: Figure_5_(rates_of_root_carboxylate_exudation_of_seedlings_grown_in_an_aerated_nutrient_solution).csv **Description:** Total effective carboxylate is calculated by summing up the concentrations the sum of all di- and tri-carboxylates, with mainly citrate, malate and oxalate. All carboxylate concentrations are expressed per unit root fresh weight. Our results showed that all the selected plant species, which exhibited either relatively high or low leaf [Mn] all released carboxylates when grown in low-P nutrient solution. ##### Variables * Seedling ID: The 6-12 years old seedlings of Ericaceae  grown in glasshouse to measure root carboxylate exudation * Total effective carboxylate: with mainly citrate, malate and oxalate * Rates of root carboxylate exudation (nmol g-1 FMs-1):  All carboxylate concentrations are expressed per unit root fresh weight. ## Code/software All analyses for Figure 2,3,4  were conducted in R v.3.6.3 (R_Development_Core_Team 2019) using R base packages. Figure 5 we used Standardised Major Axis regression (SMA) to examine the correlation between leaf [Mn] and leaf [P] of targeted Ericaceae species in their low-P natural habitats and mapped the leaf [P] and [Mn] onto the phylogeny for visualisation, using the ‘contMap’ function in phytools in R ## Access information Other publicly accessible locations of the data: * [https://doi.org/10.1071/SB14041_AC](https://doi.org/10.1071/SB14041_AC) Data was derived from the following sources: * n/a