Leave land alone following natural disasters, say researchers

Despite responses to wildfires as being disasters that require human care, these natural disturbances are important ecosystem processes that should be left alone-a move that will increase the area’s recovery chances, says a University of Alberta researcher.

Following a forest fire, there is typically an attempt to recoup economic losses by salvage harvesting large volumes of timber in the affected area, but this philosophy needs to be reexamined, said Dr. Fiona Schmiegelow, who co-authored a paper just published in the prestigious journal Science.

Schmiegelow and Dr. David Lindenmayer from the Australian National University, found that salvage harvest operations after natural disturbances can threaten some organisms when large quantities of biological legacies are removed. “This may result in compounding, cumulative or magnified effects on ecosystem processes and elements of the biota if an intense natural disturbance event is soon followed by an intensive human disturbance,” said Schmiegelow, a professor in the Department of Renewable Resources.

The research team argues that large areas need to be exempt from salvage practices to maintain key ecological processes and facilitate recovery following the disturbance, but where these practices are done, strict policies need to be in place.

Catastrophic events can aid ecosystem restoration by recreating some of the structural complexity and landscape diversity lost through previous intense management of natural resources. For example, floods can reshape areas and revitalize human-modified aquatic ecosystems while major wildfires generate significant volumes of dead snags and downed trees that provide important habitat often depleted by certain forestry practices.

Although scientists now recognize the importance of natural disturbances and the biological legacies produced by them, policy makers and natural resources managers are lagging behind, say the authors. “Maintaining large areas where the natural disturbance regime operates unimpaired by human activities is an important component of any biological conservation strategy, and for ecological sustainability,” said Schmiegelow.