DOI: 10.5061/dryad.q3fv55j
title: Data from: Plasticity in root symbioses following shifts in soil nutrient availability during long-term ecosystem development

description: 1. The vast majority of terrestrial plants form root symbioses with
 arbuscular mycorrhizal (AM) fungi to enhance nutrient (particularly
 phosphorus, P) acquisition, but some plant species also form dual
 symbioses involving ectomycorrhizal (ECM) fungi, with a subset of those
 also forming triple symbioses also involving dinitrogen (N2)-fixing
 bacteria. Whether these plants show plasticity in root symbioses to
 optimise nutrient acquisition depending on the type and strength of soil
 nutrient limitation (e.g., N vs. P) has been suggested, yet empirical
 evidence remains limited. Alternatively, the degree of investment or
 ‘preference’ in particular root symbioses might simply reflect differences
 in inoculum potential among soils of contrasting nutrient availability,
 reflecting adaptations of root symbionts to different edaphic conditions.
 2. Here, we grew two co-occurring plant species forming triple (AM / ECM /
 N2-fixing; Acacia rostellifera) or dual (AM / ECM; Melaleuca systena)
 symbioses in soils of increasing age and contrasting nutrient availability
 from an Australian long-term soil chronosequence to disentangle the
 relative importance of abiotic factors (e.g., soil nutrient availability
 and stoichiometry) and biotic factors (e.g., soil inoculum potential) in
 determining root colonisation patterns and functional outcomes of these
 multiple root symbioses. 3. For both plant species, we found clear
 hump-shaped plant growth patterns along the pedogenesis-driven gradient in
 soil nutrient availability, with peak growth in intermediate-aged soils,
 while high levels of mycorrhizal colonisation by the ‘preferred’ root
 symbionts was maintained. We found large increases (540%) in foliar
 manganese concentrations with increasing soil age and declining P
 availability, suggesting that plants are also relying on the release of
 carboxylates to help acquire P in the most impoverished soils. Finally, we
 found that soil abiotic properties, such as strong differences in soil
 nutrient availabilities, are generally more important than soil inoculum
 potential in explaining these shifts in our plant and root responses. 4.
 Synthesis. Our study suggests that plants capable of forming multiple root
 symbioses show plasticity in their nutrient-acquisition strategies
 following shifts in soil nutrients during long-term ecosystem development,
 yet maintain a preference for certain root symbionts despite changes in
 soil microbial inoculum.
description: PlantGrowthPlant species growth data incluiding initial predicted biomassgrowth.csvfoliarNutrients-Using_Average_for_values_below_detection_limitfoliarNutrients-Using_Average_for_values_below_detection_limitfoliarNutrients-Using_detection_limit_itself_for_values_below_detection_limitfoliarNutrients-Using_detection_limit_itself_for_values_below_detection_limitfoliar15NPlant species foliar 15NmycorrhizasArbuscular and ectomycorrhizal fungal colonization data for both plant specieshyphalLengthExtraradical fungal hyphal length counts for soil samples taken from pots of both plant species