Variability of the flammability of plants in Turkish red pine (Pinus brutia Ten.) forests at population, species and community levels, and the relationship of this variability with the fire regime

The flammability traits of plants are important for understanding the relationship between plant communities and fire regimes in fire-prone ecosystems. Recent studies have argued that plant functional traits related to flammability show variability among populations and that the fire regime may be responsible for this variability. Within the scope of this thesis, it is aimed to investigate the flammability traits at species, population and community levels in Mediterranean maquis species in Pinus brutia forests. It is also aimed to reveal how the flammability traits vary under different fire regimes and to classify the responses of the examined species to fire based on the basic flammability components. In this study, plant flammability was investigated under three main sections: inter- and intra-specific variability in plant flammability traits, the variation of these traits depending on the fire regime, and their relationship with the flammability components. Field studies were carried out in Muğla and Antalya in Southwest Anatolia, where are two provinces Turkey's most frequent forest fires occur. We selected the most-abundant 26 maquis species in these forests and measured nine flammability traits (leaf dry matter content, specific leaf area, fuel moisture content, branching, leaf curliness, leaf thickness, the proportion of dead fine- fuel, dead to live fuel ratio and the proportion of coarse and fine fuel) in the field and laboratory. In order to reveal the relationship between leaf traits and flammability components, leaves were burned experimentally by using a muffle furnace at an average temperature of 400 - 430ºC and flammability classes were revealed at the species level. The results showed how the plant traits associated with flammability vary among plant communities, species and populations in different areas, and their relationships with flammability components (ignitability, sustainability, combustibility, and consumability). The findings showed that all the studied flammability traits significantly vary among species and flammability strategies of plants in fire-prone Mediterranean pine forests are species-specific. The evidence obtained from this thesis supports the idea that flammability traits are important biological traits that have to be considered to understand the ecology and evolution of plant species in fire-prone ecosystems. Revealing flammability of plants will help the selection of species for the restoration of Mediterranean habitats, to establish fire-resistant plant communities when necessary, and to decrease the future fire danger. Keywords: Plant Functional Traits, Variability, Flammability, Fire Regime, Forest fire, Pinus brutia.