Data from: Fuels and fires influence vegetation via above- and below-ground pathways in a high-diversity plant community

1. Fire strongly influences plant populations and communities around the
world, making it an important agent of plant evolution. Fire influences
vegetation through multiple pathways, both above- and belowground. Few
studies have yet attempted to tie these pathways together in a mechanistic
way through soil heating even though the importance of soil heating for
plants in fire-prone ecosystems is increasingly recognized. 2. Here we
combine an experimental approach with structural equation modelling (SEM)
to simultaneously examine multiple pathways through which fire might
influence herbaceous vegetation. In a high-diversity longleaf pine
groundcover community in Louisiana, USA, we manipulated fine-fuel biomass
and monitored the resulting fires with high-resolution thermocouples
placed in vertical profile above- and belowground. 3. We predicted that
vegetation response to burning would be inversely related to fuel load
owing to relationships among fuels, fire temperature, duration and soil
heating. 4. We found that fuel manipulations altered fire properties and
vegetation responses, of which soil heating proved to be a highly accurate
predictor. Fire duration acting through soil heating was important for
vegetation response in our SEMs, whereas fire temperature was not. 5. Our
results indicate that in this herbaceous plant community, fire duration is
a good predictor of soil heating and therefore of vegetation response to
fire. Soil heating may be the key determinant of vegetation response to
fire in ecosystems wherein plants persist by resprouting or reseeding from
soil-stored propagules. 6. Synthesis. Our SEMs demonstrate how the complex
pathways through which fires influence plant community structure and
dynamics can be examined simultaneously. Comparative studies of these
pathways across different communities will provide important insights into
the ecology, evolution and conservation of fire-prone ecosystems.