Context. Understanding fire and inundation impacts on wetland vegetation communities is crucial for effective post-fire wetland management. Aims. We aimed to determine the impact of post-fire inundation on plant community structure and seedling germination and establishment after a large wildfire. We asked two questions, namely (1) did fire, drought or inundation affect plant communities the most; and (2) did fire or inundation affect seedling germination and establishment? Methods. Using a before–after–control–impact (BACI) design, we monitored vegetation changes in water-couch wetland communities before and after a wildfire. Also, soil samples were collected from burnt and unburnt sites and assessed for impacts of fire and post-fire inundation regimes on seed germination and seedling establishment. Key results. Inundation variables had more pronounced and more consistent impacts on vegetation measures than did fire or drought variables. Fire impacts were mainly short-term, with impact thresholds at 72 and 143 days after fire. Low germination levels and zero seedling survival were observed without inundation. Conclusions. Fire was a major but short-term contributor to wetland vegetation change, whereas drought had longer-term impacts, and inundation regimes had the greatest impacts. Implications. Providing a range of inundation conditions post-fire may enhance wetland vegetation recovery and have modifying effects on invasive species.

Increased need for freshwater for human uses from the mid-1900s has severely impacted rivers and floodplain wetlands so that they are some of the most seriously degraded environments in the world. Research and monitoring in this area to date has focused on understanding 'flow-ecology' relationships, without investigating the mechanisms underlying them. The use of species traits offers a tool for defining mechanistic connections between biotic responses and environmental conditions. We examined nine macroinvertebrate trait categories in both wetlands and channels to determine whether their profiles responded to hydrology in the Gwydir River system in the northern Murray-Darling Basin, Australia. Trait responses were shown for the wetlands but not the river channels. Twelve traits showed positive relationships with the time the wetlands were connected to their river channels. It is unclear the reason(s) why the river channel invertebrate traits did not respond to hydrology. However, the use of environmental flows in the river systems may be important to other aspects of macroinvertebrate assemblages such as their role in food webs to support higher-order consumers.