Shade alters grass growth and architecture by reducing root biomass

Variable tree cover characterizes tropical grassy biomes. Light availability in the ground layer becomes increasingly limited as tree cover increases while open canopy environments are associated with a flammable grassy ground layer. Grass species dominating the ground layer of these ecosystems have adopted strategies to persist and proliferate with frequent fire. However, there is limited understanding of how grass growth and flammability traits respond to changes in light availability. We experimentally grew 14 grass species characteristic of the Malagasy Central Highlands for one year with four treatments of light exclusion ranging from 0 – 60%. Six plant functional traits and four leaf flammability traits were measured: plant height, bulk density, aboveground biomass, belowground biomass, ratio of root to shoot biomass, specific leaf area, leaf heat release capacity, temperature of maximum decomposition, total heat release and peak heat release rate. Belowground biomass, the ratio o...