Pine trees intensified 2017 fires

Invasive pine trees significantly intensified the June 2017 Garden Route fires‚ scientists said on Thursday.

Pines have invaded more than 90% of the Garden Route National Park’s fynbos vegetation at various densities‚ according to a study published in the journal Fire Ecology.

Co-author Professor Brian van Wilgen‚ of the Centre of Excellence for Invasion Biology at Stellenbosch University, said acacias and bluegums had contributed to the fuel load available for the fire‚ which burnt 15‚000ha‚ destroyed 800 buildings and left seven people dead.

Van Wilgen‚ whose research team included academics from Nelson Mandela University‚ SA National Parks and the CSIR, said: “By increasing the amount of fuel available to burn‚ the fires become more intense and more difficult to control.”

The team found the severity of the fire‚ which claimed more than 5‚000ha of commercial pine plantations‚ was significantly higher in plantations of invasive alien trees and in fynbos invaded by alien trees‚ than in fynbos that was not invaded.

The two-year drought that preceded the fires was the worst on record and contributed significantly to the disaster‚ the researchers said.

And they warned that similar fires could become more frequent as global warming takes its toll on the climate of the Southern Cape.

The study used satellite imagery to compare the landscape before and afterwards‚ including vegetation types. –