Flowers that cool themselves: Thermal ecology of summer‐blooming thistles in hot Mediterranean environments DOI
Carlos M. Herrera

Ecological Monographs, Journal Year: 2025, Volume and Issue: 95(1)

Published: Feb. 1, 2025

Abstract Flower exposure to high temperature reduces the production, viability, and performance of pollen, ovules, seeds, which in turn impairs individual fecundity risks survival populations. Autonomous floral cooling could alleviate effects flower harmful temperatures, yet investigations on thermal ecology flowers hot environments are needed evaluate reality, magnitude, ecological significance thermoregulatory cooling. This paper reports a study heads (=capitula) 15 species summer‐blooming Asteraceae, tribe Cardueae, from hot‐dry habitats southern Iberian Peninsula. Temperature inside ( T ) outside out capitula were assessed under natural field conditions using two complementary sampling measurement procedures, provided information relationships between temperatures at levels (“continuous recording”) local plant populations (“instantaneous measurements”). Baselines for – relationship absence physiological activity obtained by exposing dehydrated variable ambient field. To assess whether co‐flowering Asteraceae defined collectively distinct layer, vertical distribution relative ground was quantified. Bees visiting watched air beside visited capitulum measured. Results remarkably similar all species. The experienced during long periods, their interior cooler than most time, with differentials (Δ = − often approaching, sometimes exceeding −10°C. best described composite one steep shallow linear separated breakpoint (Ψ, interspecific range 25–35°C). Capitula only weakly thermoregulated when < Ψ, but switched closely > Ψ. Narrow distributions above responses resulted “refrigerated layer” where bees foraged Ψ presumably cooled capitula. Thermoregulatory refrigeration (“thermal engineering”) can benefit not reproduction reducing pollen ovule summer also bee pollinators other floricolous insects.

Language: Английский

Flowers that cool themselves: Thermal ecology of summer‐blooming thistles in hot Mediterranean environments DOI
Carlos M. Herrera

Ecological Monographs, Journal Year: 2025, Volume and Issue: 95(1)

Published: Feb. 1, 2025

Abstract Flower exposure to high temperature reduces the production, viability, and performance of pollen, ovules, seeds, which in turn impairs individual fecundity risks survival populations. Autonomous floral cooling could alleviate effects flower harmful temperatures, yet investigations on thermal ecology flowers hot environments are needed evaluate reality, magnitude, ecological significance thermoregulatory cooling. This paper reports a study heads (=capitula) 15 species summer‐blooming Asteraceae, tribe Cardueae, from hot‐dry habitats southern Iberian Peninsula. Temperature inside ( T ) outside out capitula were assessed under natural field conditions using two complementary sampling measurement procedures, provided information relationships between temperatures at levels (“continuous recording”) local plant populations (“instantaneous measurements”). Baselines for – relationship absence physiological activity obtained by exposing dehydrated variable ambient field. To assess whether co‐flowering Asteraceae defined collectively distinct layer, vertical distribution relative ground was quantified. Bees visiting watched air beside visited capitulum measured. Results remarkably similar all species. The experienced during long periods, their interior cooler than most time, with differentials (Δ = − often approaching, sometimes exceeding −10°C. best described composite one steep shallow linear separated breakpoint (Ψ, interspecific range 25–35°C). Capitula only weakly thermoregulated when < Ψ, but switched closely > Ψ. Narrow distributions above responses resulted “refrigerated layer” where bees foraged Ψ presumably cooled capitula. Thermoregulatory refrigeration (“thermal engineering”) can benefit not reproduction reducing pollen ovule summer also bee pollinators other floricolous insects.

Language: Английский

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