Interspecific facilitation of micronutrient uptake between cluster-root-bearing trees and non-cluster rooted-shrubs in a Banksia woodland

Christiana Staudinger; Michael Renton; Matthias Leopold; Jun Wasaki; Erik J Veneklaas; Patrícia de Britto Costa; Gustavo Boitt; Hans Lambers

doi:10.1007/s11104-023-06092-6

Interspecific facilitation of micronutrient uptake between cluster-root-bearing trees and non-cluster rooted-shrubs in a Banksia woodland

Plant Soil. 2024;496(1-2):71-82. doi: 10.1007/s11104-023-06092-6. Epub 2023 Jun 21.

Authors

Christiana Staudinger^#^{1

2

3

4}, Michael Renton^#¹, Matthias Leopold⁵, Jun Wasaki⁴, Erik J Veneklaas¹, Patrícia de Britto Costa⁶, Gustavo Boitt⁵, Hans Lambers¹

Affiliations

¹ School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, 6009 Australia.
² The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, 6009 Australia.
³ Institute of Agronomy, Institute of Soil Science, University of Natural Resources and Life Sciences, BOKU Vienna, 3400 Tulln, Austria.
⁴ Graduate School of Integrated Sciences of Life, Hiroshima University, Higashi-Hiroshima, 739-8521 Japan.
⁵ School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, 6009 Australia.
⁶ Department of Geography, University of Exeter, Exeter, EX4 4RJ UK.

^# Contributed equally.

Abstract

Background and aims: Belowground interspecific plant facilitation is supposed to play a key role in enabling species co-existence in hyperdiverse ecosystems in extremely nutrient-poor, semi-arid habitats, such as Banksia woodlands in southwestern-Australia. Manganese (Mn) is readily mobilised by Banksia cluster root activity in most soils and accumulates in mature leaves of native Australian plant species without significant remobilisation during leaf senescence. We hypothesised that neighbouring shrubs are facilitated in terms of Mn uptake depending on distance to surrounding cluster root-forming Banksia trees.

Methods: We mapped all Banksia trees and selected neighbouring shrubs within a study site in Western Australia. Soil samples were collected and analysed for physical properties and nutrient concentrations. To assesses the effect of Banksia tree proximity on leaf Mn concentrations [Mn] of non-cluster-rooted woody shrubs, samples of similarly aged leaves were taken. We used multiple linear models to test for factors affecting shrub leaf [Mn].

Results: None of the assessed soil parameters showed a significant correlation with shrub leaf Mn concentrations. However, we observed a significant positive effect of very close Banksia trees (2 m) on leaf [Mn] in one of the understorey shrubs. We found additional effects of elevation and shrub size.

Conclusions: Leaf micronutrient concentrations of understorey shrubs were enhanced when growing within 2 m of tall Banksia trees. Our model predictions also indicate that belowground facilitation of Mn uptake was shrub size-dependent. We discuss this result in the light of plant water relations and shrub root system architecture.

Supplementary information: The online version contains supplementary material available at 10.1007/s11104-023-06092-6.

Keywords: Banksia woodland; Bossiaea eriocarpa; Carboxylates; Cluster roots; Facilitation; Hibbertia hypericoides; Leaf manganese; Root-root interactions; Size-dependent resource allocation; Spatial analysis.