Thermal limits and sensitivity of Brosimum rubescens Taub. (Moraceae): Implications for monodominance in a warming climate
Year: 2026
Type: dataset
Abstract: In B. rubescens monodominant forests, increasing gap formation has been documented over time. While moderate disturbance may enhance the growth and recruitment of established seedlings, excessive gap formation can alter microclimate and soil conditions beyond the species’ optimal range. Combined with recent warming and reduced regeneration following El Niño, these changes may jeopardize monodominance. We investigated whether thermal tolerance and sensitivity vary across canopy conditions. We also measured leaf traits influencing heat regulation, such as leaf thickness, water content, and stomatal conductance. These traits affect radiation interception and heat dissipation. For instance, thicker leaves may reduce thermal conductivity, trapping heat, though findings are mixed . Higher water content improves cooling and stress tolerance, while stomatal conductance increases evaporative cooling until a threshold, beyond which closure elevates leaf temperature. In this context, considering that B. rubescens seedlings can establish and persist under shaded conditions, forming a dense seedling bank, while canopy gaps primarily promote their growth and recruitment, we evaluated (1) whether B. rubescens leaves from open-canopy sites exhibit lower heat tolerance than those from closed-canopy sites. We hypothesized that individuals in open-canopy environments would experience greater thermal and radiative exposure, potentially leading to reduced heat tolerance and increased thermal stress compared to those growing under closed canopies. We also evaluated (2) whether heat tolerance is associated with leaf traits, hypothesizing that heat tolerance would be positively correlated with greater leaf thickness, higher leaf water content, and higher stomatal conductance, reflecting their roles in enhancing transpirational cooling and mitigating heat stress.
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220719585