Tree rings can tell region’s ancient fire history
Washington: Trees can provide secrets about past events, and their rings can especially yield key information about fires, some of which happened hundreds of years ago, a US researcher says.
Charles Lafon, associate professor of geography, who has studied the fire history of forests throughout the southern and central Appalachian Mountains, says that some trees have a lot to tell — one tree he examined endured 14 separate fires through its lifetime.
Lafon analyzed the tree rings of several pine species and found clear evidence of “scarring,” a disfiguring of the wood that is the unmistakable sign of a previous fire.
More examinations showed that trees in the area had sustained numerous fires over the past centuries.
“We found one tree that has had at least 14 fires, and we found many other trees that had endured multiple fires,” he said.
By piecing together the fire-scar record from numerous trees, he and his students and collaborators learned that fires occurred frequently, about once every 2-10 years. He found some trees with scars dating back to the mid-1600s.
“We know that Indians often set fires to clear areas, and from records we have learned that the early settlers of the area also set fires so they could clear lands for grazing and planting crops,” he says.
A demand for lumber in the late 1800s and early 1900s led to a tremendous amount of logging, he said, and fires were seen as a threat to a natural resource, motivating the fire protection campaigns of the 20th century.
“The point is, there have always been fires in forests. Sometimes fires are a good thing because they are nature''s way of starting over and producing new growth, and sometimes they are destructive,” he added.
The study has been published in Applied Vegetation Science and Physical Geography.