Species composition and fire: non-additive mixture effects on ground fuel flammability

• Published in: Frontiers in Plant Science
• Main Authors: Cassandra eVan Altena, Richard evan Logtestijn, William eCornwell, Hans eCornelissen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2012
• Subjects: trait; Biodiversity; carbon cycling; fire regime; fuel type; non-additivity; Plant culture; SB1-1110; Subarctic
• Online Access: https://doi.org/10.3389/fpls.2012.00063; https://doaj.org/article/4f3074545e444c1f88f0e98a7c333f73

Biodiversity effects on many aspects of ecosystem function have been well documented. However, fire is an exception: fire experiments have mainly included single species, bulk litter, or vegetation, and, as such, the role of biodiversity as a determinant of flammability, a crucial aspect of ecosystem function, is poorly understood. This study is the first to experimentally test whether flammability characteristics of two-species mixtures are non-additive, i.e. differ from expected flammability based on the component species in monoculture. In standardized fire experiments on ground fuels, including monocultures and mixtures of five contrasting subarctic plant fuel types in a controlled laboratory environment, we measured flame speed, flame duration and maximum temperature. Broadly half of the mixture combinations showed non-additive effects for these flammability indicators; these were mainly enhanced dominance effects, where the fuel types with the more flammable value for a characteristic determined the flammability of the whole mixture. The high incidence of species non-additive effects on ground fuel flammability suggest that the combinations of fuel types may have important effects on ground fire regimes in vegetations differing or changing in species composition.