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

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 thermal niche,
incorporating seed dormancy and mortality temperature responses, 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
if the pyro-thermal niche is aligned 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 dormancy
release 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 LT50, Topt, and
DRT50. Seeds of Pomaderris (Rhamnaceae) had the highest Topt and
LT50, and Pomaderris bodalla having the highest DRT50 of 101.3°C. Seeds
from species within this family exhibited higher temperature thresholds
than those from Fabaceae. Seed mass was only influential in explaining
LT50 variation.