Defining the pyro-thermal niche do seed traits, ecosystem type and phylogeny influence thermal thresholds in seeds with physical dormancy?

Defining the pyro-thermal niche : do seed traits, ecosystem type and phylogeny influence thermal thresholds in seeds with physical dormancy?

© 2025 The Author(s). New Phytologist © 2025 New Phytologist Foundation.

Détails bibliographiques
Publié dans:The New phytologist. - 1979. - 246(2025), 4 vom: 23. Mai, Seite 1567-1582
Auteur principal: Tangney, Ryan (Auteur)
Autres auteurs: McInnes, Sarah J, Dalziell, Emma L, Cornwell, William K, Miller, Ben P, Auld, Tony D, Ooi, Mark K J
Format: Article en ligne
Langue:English
Publié: 2025
Accès à la collection:The New phytologist
Sujets:Journal Article physical dormancy postfire germination pyro‐thermal niche seed dormancy seed survival
Description
Résumé:© 2025 The Author(s). New Phytologist © 2025 New Phytologist Foundation.
Seeds are a key pathway for plant population recovery following disturbance. To prevent germination during unsuitable conditions, most species produce dormant seeds. In fire-prone regions, physical dormancy (PY) enables seeds to germinate after fire. The pyro-thermal niche, incorporating temperature effects into seed dormancy and mortality, has not been characterised for PY seeds from fire-prone environments. We aimed to assess variation in thermal thresholds between species with PY seeds and whether the pyro-thermal niche is correlated with seed mass, ecosystem type or phylogenetic relatedness. We collected post heat-shock germination data for 58 Australian species that produce PY seeds. We applied species-specific thermal performance curves to define three critical thresholds (DRT50, dormancy release temperature; Topt, optimum temperature; and LT50, lethal temperature), defining the pyro-thermal niche. Each species was assigned a mean seed weight and ecosystem type. We constructed a phylogeny to account for species relatedness and calculated phylogenetic signal (h2) for DRT50, Topt and LT50. We found a consistent inverted u-shaped thermal response curve across all species examined. Seeds from species within Rhamnaceae exhibited higher temperature thresholds than those from Fabaceae. Seed mass was influential in explaining LT50 variation. The pyro-thermal niche analysis presented here provides a framework for direct comparisons between other fire-prone and nonfire-prone species, in which heat may play a role in postfire germination dynamics
Description:Date Completed 24.04.2025
Date Revised 24.04.2025
published: Print-Electronic
Citation Status MEDLINE
ISSN:1469-8137
DOI:10.1111/nph.70061