Investigation of wood resistance of tree species in Zagros forests against fire (Case study of Romeshkan city)

Today, the phenomenon of fires as one of the natural disasters threatens a large part of the world's forests. The purpose of this study is to investigation of wood resistance of different tree species of Zagros forests against fire.

To conduct this research, wood species Quercus persica, Pistacia atlantica, Amygdalus scoparia, Crataegus azarolus, Acer monspessulanum and Ficus carica were prepared in two forms: dry and wet wood (with natural moisture) with similar length and dimensions (length 60 cm, diameter 15 cm). For each tree, wood with skin and without skin was selected in order to investigate the effect of stem skin on the burning rate of wood species and the difference in wood burning time was measured using a stopwatch. LPG capsule was used to create a suitable temperature for complete burning of wood. For each wood 4 treatments (wet with skin, wet without skin, dry with skin and dry without skin) and also for each treatment 10 replications were considered. Statistical analysis was performed using GLM and Independent Samels T test.

Comparison of the complete burning time of wet wood of the studied species shows that Quercus Persica wood with a time of 50 minutes until complete burning has the highest fire resistance and after that, the Pistachia had the highest resistance with 42 minutes until it burned completel. Acer and ficus varieties had the lowest fire resistance with 35 and 30 minutes to complete burning, respectively. The results also showed that fire resistance between species Crataegus and Amygdalus was not significant at 5% probability level. Comparison of the complete burning time of dry wood of the species shows that the highest fire resistance was in Quercus species with 40 minutes until complete burning. After that, Pistacia, Amygdalus, Acer, Crataegus and Ficus had 34, 30, 26, 21 and 20 minutes to burn completely in the fire, respectively. The results of comparing the means showed that in wet woods, the biggest difference in the time of complete burning of wood with and without skin in Pictacia species with 13 minutes, followed by Amygdalus and Crataegus with 12 minutes, then Quercus, Acer and ficus with 11, 9 and 6 minutes, respectively. In dry wood, the biggest difference in the time of complete burning of wood with skin and without skin in Quercus species and Pistacia with 15 minutes and then Amygdalus, Acer, Crataegus and ficus with 13, 8, 4 and 3 minutes, respectively.

The results show that the thickness of the skin and moisture of the wood cause significantly increases the resistance of the wood against fire.