A study, published in this month’s issue of the Journal of Environmental Management, has found that a species of Cypress tree, Cupressus sempervirens, is resistant to fire.
Researchers involved in the long running CypFire project ended up discovering the fire resistance by accident. Originally the researchers set out to test the resistance of Mediterranean Cypress to a pathogenic fungus. To do this a large plot was planted in Andilla, Valencia in 2012. Sadly, during the trial, a forest fire swept over the area and the researchers returned to find that it was only the Cypress trees that remained standing.
Botanist Bernabé Moya recalls his surprise at the time,
“On our way to what we knew would be a Dante-esque scene during that tragic summer, we felt deep sadness at the thought of losing a plot of such value to the conservation of biodiversity. When we got there we saw that all the common oaks, holm oaks, pines and junipers had completely burnt. But only 1.27% of the Mediterranean cypresses had ignited.”
This fire lead to a 3 year study on fire resistance which has just been published. The researchers found the trees have a number of unusual features that make them resistant to fire.
“We observed that the Mediterranean cypress, because of the particular structure of its leaves, is able to maintain a high water content even in situations of extreme heat and drought, and this is a very favourable starting point concerning fire risk,” explains Mr Della Rocca, a researcher on the project
The leaf litter also retains water and acts as a sponge to slow down fire in the area. The trees have a particular branching pattern which means that the canopy is very sparse and any dead parts of the tree fall to the ground rather than getting caught in the foliage.
One of the main problems with trees such as pine is that the resin in the tree acts as an accelerant to fire. Once againthe Cypress trees are different as their resin doesn’t appear to combust. Researchers are now launching a second study into this feature.
Between 2006 and 2010 were 270,000 fires in Mediterranean forests and so the findings of the study are set to have huge repercussions as these trees make effective fire barriers. The researchers say the trees could grow equally well in Latin America or California where forest fires are often a problem.
“In a few years, we will have Cypress barriers and observations at real scale,” Mr Della Rocca says, which can only be a good thing really.