Change in fire frequency drives a shift in species composition in native <scp> <i>Eucalyptus regnans</i> </scp> forests: Implications for overstorey forest structure and transpiration

The world's most iconic forests are under threat from climate change. Climate-fire-vegetation feedback mechanisms altering the usual successional trajectories of forests. Many obligate seeder across globe experiencing regeneration failures and subsequent alterations to their recovery trajectories. For example, persistence Eucalyptus regnans F. Muell. in southeast Australia is highly vulnerable effects climate-driven increases wildfire frequency. Shortening return interval >100 years < 20 would inhibit or entirely stop E. regnans, leading replacement with understorey species such as Acacia dealbata Link. In this study, it hypothesised that following replacement, forest overstorey structure transpiration will diverge. An experiment was designed test hypothesis by measuring comparing structural properties, including sapwood area leaf area, between A. over a chronosequence (10-, 20-, 35- 75-/80-year-old forests). We found significantly diverged two types throughout life cycle after age 20. study revealed strikingly different temporal patterns water use, indicating significant eco-hydrologic change result replacement. Overall, results provide strong indication 20, Acacia-dominated substantially lower than they replace. This difference may lead divergence yield forested catchments where widespread.