Xinglei Cui;Adrian M. Paterson;George L. Perry;Sarah V. Wyse;Azharul Alam;Congde Huang;Shixing Zhou;Xinghua Lin;Changhong Lai;Fang He;Dongyu Cao;Kate L. A. Marshall;Timothy J. Curra

Sichuan Province Forestry and Grassland Environmental Monitoring Centre, Chengdu, 610036, China;Department of Pest-management and Conservation, Lincoln University, Lincoln, 7647, New Zealan;Department of Pest-management and Conservation, Lincoln University, Lincoln, 7647, New Zealand;Bio-Protection Research Centre, Lincoln University, Lincoln, 7647, New Zealand; National Forestry and Grassland Administration Engineering Research Centre for Southwest Forest and Grassland Fire Ecological Prevention, College of Forestry, Sichuan Agricultural University, Chengdu, 611130, China;National Forestry and Grassland Administration Engineering Research Centre for Southwest Forest and Grassland Fire Ecological Prevention, College of Forestry, Sichuan Agricultural University, Chengdu, 611130, China;School of Environment, University of Auckland, Auckland, 1142, New Zealand

Dracophyllum;Fire;Flammability;Habitat;PHENOTYPIC PLASTICITY;LEVEL FLAMMABILITY;ALPINE PLANT;EVOLUTION;ECOLOGY;ADAPTATION;VEGETATION;GRADIENT;ALTITUD

Flammability is a compound plant trait that can vary significantly across natural populations within species. Investigating intraspecific variation in flammability provides insights into the evolution of plant flammability and inform understanding of wildfire risk and behaviour in different habitats. We measured four flammability variables, representing ignitibility (time to ignition), sustainability (total burning time), combustibility (maximum temperature during burning) and consumability (percentage of biomass consumed by fire) to assess the shoot-level flammability of Dracophyllum rosmarinifolium (G. Forst.) (Ericaceae), a polymorphic endemic species distributed throughout New Zealand. We examined the relationship between flammability components and a suite of climatic and geographic variables (elevation, latitude, mean annual temperature (MAT), mean annual rainfall (MAR) of the sample locations, etc.). We measured shoot-level flammability components of 62 individuals across eight populations. Burning time, maximum temperature and burnt biomass were positively correlated with each other, while ignition score was independent of other flammability components. All flammability components varied significantly across the eight populations. The habitat conditions we considered were not related to any of the shoot-level flammability components of D. rosmarinifolium. Intraspecific variation in flammability in D. rosmarinifolium may be a byproduct of selection on other functional traits, such as leaf size, shoot lipid content, indicating that plant flammability is an incidental result, rather than selected for, at least in ecosystems without fire as a selective force.