Biology subjects

Brodribb, T.

Publications and source records attributed to Brodribb, T..

4 recordsLinked to original sources

bioRxiv2026

The origin of mechanical advantage in angiosperms

O_LIMechanical interaction between guard cells and epidermal pavement cells enables large stomatal apertures and high productivity in angiosperms. We do not know when this response evolved, but over the last 169 years we have found that mechanical advantage has been tested in at least 230 species from 85 families. To date no data on this trait exists among angiosperms outside magnoliids, monocots and eudicots. C_LIO_LITo resolve the evolutionary origins of this critical stomatal response we tested for mechanical advantage across 14 additional species including the earliest diverging lineages of angiosperms. C_LIO_LIWe find that mechanical advantage, while variable in magnitude, is present in all angiosperm species that have been measured, including Amborella trichopoda sister to all angiosperms. C_LIO_LIThis response likely evolved once in flowering plants, in the common ancestor of this clade, remaining widespread across angiosperms today. We hypothesize that angiosperms could not have realized the full potential of physiological innovations in water transport without the evolution of this key trait that increased operational stomatal aperture. C_LI

plant biology↗

bioRxiv2025

Root vulnerability to embolism and lack of physiological recovery limit the competitive ability of an invasive palm

O_LIClimate change and invasive species both threaten forest ecosystems. While exacerbated droughts drive tree mortality, species invasion alters forest composition. Invasive plants may be more vulnerable to drought due to acquisitive traits and low embolism resistance, but their potentially superior recovery capacity raises key uncertainties in predicting future species distributions. C_LIO_LIWe compared the drought resistance and recovery of an invasive palm (Trachycarpus fortunei) with two native species (Ilex aquifolium & Tilia cordata) from the Southern Alps. Saplings were exposed to increasing intensities of drought-induced xylem embolism, then rewatered for 45 days. Among others, we tracked net assimilation (Anet), stomatal conductance (gs), and leaf water potential ({Psi}leaf) before and after the drought, and modeled the time to hydraulic failure in leaves, stems, and roots. C_LIO_LIWhile the invasive palm had exceptionally drought-tolerant leaves, its roots were the most drought-sensitive among all species. The palm maintained positive gas exchange until {Psi}leaf of -4 MPa, as some native species; however, it failed to recover from the most severe drought, with simulations showing root embolism preceding leaf failure, unlike native species. C_LIO_LIInvasive plants may match or exceed natives drought resistance, but their inability to recover from extreme droughts could limit their future spread. C_LI

ecology↗

bioRxiv2025

Conserved strategies underpin the replicated evoluton of aridity tolerance in trees

Predicting forest responses to climate change requires a detailed understanding of trait-environment coordination. Adaptation to environment comprises both conserved and labile components of trait variation. However, few studies explore the decomposition of trait-environment relationships in a rigorous phylogenetic framework. Combining a revised phylogeny with trait, climate and soil data to achieve unprecedented species coverage ([~]85%), we identified patterns of replicated evolution that allowed the evergreen tree genus, Eucalyptus, to rapidly radiate across Australia in response to aridification. Eucalypts from arid regions are short, produce dense wood, and have small, physically robust leaves with high nitrogen content, promoting hydraulic safety and economies in photosynthetic water use. Phylogenetic modelling reveals strong niche conservatism, with adaptation to aridity occurring primarily via clade-level divergences, followed by phylogenetically independent adjustments to local conditions. Ancestral state reconstructions accounting for trends in the paleoclimate record indicate that transitions in aridity tolerance are associated with distinct signals of environmental filtering and directional selection on functional trait variation. However, astonishing repeatability of trait changes in different clades reveals a narrow optimal solution to water availability, opening a path to predict future species distributions from phylogenetically structured trait data and signalling major implications for functional and species diversity under progressive climate change.

evolutionary biology↗

bioRxiv2023

The AusTraits Plant Dictionary

Traits with intuitive names, a clear scope and explicit description are essential for all trait databases. Reanalysis of data from a single database, or analyses that integrate data across multiple databases, can only occur if researchers are confident the trait concepts are consistent within and across sources. The lack of a unified, comprehensive resource for plant trait definitions has previously limited the utility of trait databases. Here we describe the AusTraits Plant Dictionary (APD), which extends the trait definitions included in the new trait database AusTraits. The development process of the APD included three steps: review and formalisation of the scope of each trait and the accompanying trait description; addition of trait meta-data; and publication in both human and machine-readable forms. Trait definitions include keywords, references and links to related trait concepts in other databases, and the traits are grouped into a hierarchy for easy searching. As well as improving the usability of AusTraits, the Dictionary will foster the integration of trait data across global and regional plant trait databases.

ecology↗