Repeated Bushfires Transform Iconic National Park
Wilsons Promontory, one of Victoria's most beloved national parks, has been dramatically altered by repeated bushfires in the early 20th century, leading to what scientists describe as ecosystem collapse. A new study reveals that these collapsed forests have persisted for 70 years, with severe consequences for biodiversity and carbon storage.
Located on Australia's southernmost tip, the Prom is famous for its wombats, rosellas, and stunning coastlines. However, intense fires in the first half of last century pushed thousands of hectares of eucalypt forests past a tipping point. According to the study, these forests failed to regenerate and remain in a collapsed state today.
Collapsed Forests: A Stark Comparison
The research compared collapsed forest areas with nearby intact eucalypt forests. Collapsed forests had 97% fewer large trees, which are critical for nesting birds and sheltering possums, gliders, and microbats. Instead, dense shrubs dominate the landscape. Fallen trees and trunks, which provide habitat for ground-dwelling mammals like the long-nosed potoroo and the pookila, were 40% less abundant.
Carbon storage also suffered. Collapsed forests store 60% less carbon than intact forests, with carbon held mainly in short, dense shrubs that are more likely to burn in future fires, releasing stored carbon back into the atmosphere.
Eucalypts and Fire: A Delicate Balance
Australia's eucalypt forests have evolved to survive and recover from bushfires through epicormic resprouting, where new stems and leaves grow from charred trunks. However, they need time to recover between fires. Back-to-back bushfires can kill eucalypts, leading to ecosystem collapse where forest cover is lost and replaced by dense shrubs.
This phenomenon has serious implications for wildlife habitat, carbon storage, and bushfire risk. The study's findings provide a preview of what forests may look like in a warmer, more fire-prone future.
Restoration Challenges and Questions
Given that collapsed forests have persisted for decades, active intervention may be required to restore them. Options include reforestation or reseeding with more drought- and fire-tolerant species. However, the study raises complex questions about how much humans should intervene in national parks and whether restoration should aim to recreate historical ecosystems or prepare for future conditions.
"These are complex questions," said lead researcher Tom Fairman. "We need more research to know how to best protect our national parks and other vulnerable ecosystems from future fires, floods, and other natural disturbances."
Lessons for Fire-Prone Forests
The history of Wilsons Promontory serves as an urgent reminder of the need for active management and reliable funding for national parks, especially as climate change increases the frequency and severity of bushfires. "The Prom shows us forest collapse is not inevitable, but it's an urgent reminder of the importance of actively managing and investing in our national parks," Fairman added.
As Australia faces a hotter, drier future, the lessons from the Prom could help protect other fire-prone forests from a similar fate.
