Do severe wildfires make forests in the western United States more susceptible to future bark beetle outbreaks?
The answer, in a study published Monday (Nov. 7, 2016) in the Proceedings of the National Academy of Sciences, is no. By leading to variability in the density and size of trees that grow during recovery, large fires reduce the future vulnerability of forests to bark beetle attacks and broad-scale outbreaks.
“Fire creates a very heterogeneous landscape,” says study co-author Kenneth Raffa, professor of entomology at the University of Wisconsin-Madison. “Beetles can only reproduce in an individual tree once, so they take advantage of this patch of trees and that patch of trees as they become available, but when the number and size of trees vary a lot, it’s hard for a large outbreak to develop.”
Read more at: http://phys.org/news/2016-11-variable-tree-growth-forests-future.html#jCp
CHEYENNE, Wyo. (AP) — Nearly three decades ago, huge wildfires burned about a third of Yellowstone National Park. The park has seen wildfires every year since, but the forests of new trees that grew in the scars of those 1988 fires have helped curb their size and intensity — until now.
Ecologist Suzanne Simard has shown how trees use a network of soil fungi to communicate their needs and aid neighboring plants. Now she’s warning that threats like clear-cutting and climate change could disrupt these critical networks.