Contrasting physiological responses to excess heat and irradiance in two tropical savanna sedges

13049R1Trinidad’s Aripo Savanna is a rare example of an intact tropical grassland. It is a living laboratory in which to explore the mechanisms used by plants to survive the stress of life in the full glare of the equatorial sun. In a new study in AoB PLANTS, John-Bejai et al. found that the dominant species, Lagenocarpus rigidus, avoids overheating not through higher transpiration or more reflective leaf surfaces (as expected), but by altering the size and shape of its leaves to suit each location. This plasticity in leaf morphology is combined with plasticity in cell membrane properties, which allows the leaves to tolerate periods of extreme heat. In the absence of these traits a closely related species Lagenocarpus guianensis, finds its range restricted to the shaded savanna edges where heat and light are less overbearing.  The results highlight the importance of trait-plasticity to the survival of plants in the face of climate change.