Over half of Australian species decline following 2019-20 megafires

Sydney (The Uttam Hindu): Over half of Australia's animal and plant species experienced declines following the country's 2019-20 megafires, new research has found. The new research, published by Melbourne's Deakin University in Nature, analysed the impact of the 2019-20 Black Summer bushfires on 1,380 animal and plant species found in Australia. It found that 55 per cent of the species declined following the fires - either because they were less abundant overall or occupied fewer sites.

The 2019-20 fires were among the worst in Australian history, burning an estimated 24.3 million hectares of land across the country - primarily on the east coast - and causing 34 deaths directly as well as hundreds more from smoke inhalation. The new study found that mammals were disproportionately negatively affected by the fires, with average species declines twice as large as other animal groups. However, the study also found that 44 per cent of the analysed species were more commonly found in the burnt sites following the fires, with their increases generally mirroring the size of declines in other species.

The report, which was compiled by over 100 scientists, called for a major rethink of Australia's current approach to fuel-reduction burning. Prescribed burns are commonly carried out across Australia in the lead-up to bushfire season to reduce flammable materials that could fuel a fire, such as plants, fallen branches, logs, leaves and bark. The research found that the practice could create larger disruptions to ecosystems when big fires occur.

In areas that had experienced three or more fires in the 40 years prior to 2019-20, negative impacts on biodiversity were up to 93 per cent higher than in areas that had only burnt once or not at all. Additionally, sites that burnt in the 10 years before the Black Summer fires had negative effects 70 per cent larger than areas that had not burnt for at least 20 years. The study suggested that intermediate fire intervals between 11-20 years created the least disruption for biodiversity and that long intervals are needed to serve as refuges and allow for time-dependent habitat attributes such as tree hollows.