Leaf size and shape interact to control flammability: An experiment with artificial leaves cut from the large-leaved species Sapranthus palanga

Climate change is altering fire regimes globally, increasing the
occurrence, frequency, and severity of wildfires in ecosystems not
traditionally adapted to fire, including tropical forests. Understanding
the flammability of living plant tissues, particularly leaves—the most
abundant and easily ignitable plant fuel—is crucial for predicting fire
behavior and ecosystem responses. Leaf morphological traits such as size,
shape, thickness, and surface area influence key physical processes like
heat transfer, drying rate, and flame propagation, but their independent
effects remain poorly understood due to confounding biochemical factors.
To isolate the role of leaf size and shape in flammability, we performed
controlled laboratory experiments using artificial leaves cut from a
single large-leaved tropical species, Sapranthus palanga, thereby
standardizing chemical composition and venation. The dataset comprises
three experiments: (1) a control assessing differences between intact and
cut leaf margins, (2) a factorial experiment testing the interaction
between leaf shape (circular, rectangular, triangular) and size (small,
medium, large), and (3) a shape-only experiment controlling for surface
area. Measured variables include ignition time, flame duration, distance
burned, and burning rate under standardized flame exposure. This dataset
includes three files with the measured values for flammability as a
function of size, shape, and the control dataset for our pilot
study. These data provide a rigorous empirical foundation to
understand how fundamental geometric leaf traits influence flammability,
contributing to improved fire ecology models and management in tropical
ecosystems facing changing fire regimes.