Twenty years of research has found the contribution of Commonwealth environmental water to flows at the internationally recognised Narran Lakes (Dharriwaa) in New South Wales has helped build resilience in wetland vegetation.
The Commonwealth Environmental Water Holder (CEWH) and other agencies have supported a vitally important ecosystem.
The study explores long-term vegetation patterns on a timescale rare for Australian wetlands.
The recent Narran Lakes vegetation study conducted by researchers from the Australian Rivers Institute (ARI, Griffith University) builds on previous research and has provided valuable insights that will inform the use of water for the environment at Narran Lakes.
ARI Lead Researcher Dr Rebekah Grieger presented a summary of findings to CEWH staff in late 2024. Dr Grieger said it was a privilege to conduct research at Narran Lakes and to have the support of local First Nations people, the Yuwaalaraay and Euahlayi peoples.
"Narran Lakes Nature Reserve is home to a vast array of vegetation species including one of the largest areas of lignum shrubland in the Murray-Darling Basin. Within the reserve over 100 species have been identified, including some endangered plants.
"You can describe vegetation and water as the nerve system of Narran Lakes.
"The combination of vegetation and environmental water keeps the lake system healthy. We saw food and homes for native animals and good outcomes for this special ecosystem," she said.
Dr Grieger said in the past two decades she and other research staff found an overall trend of increasing vegetation species' richness and diversity.
"Vegetation responds to natural cycles of flooding and drying. Environmental water has added to recent wet conditions to give vegetation at Narran Lakes a much-needed boost.
"Plant species including fairy grass, spreading daisy, Warrego grass and Cooper clover were found to be green and healthy. But there is concern for the recovery of lignum shrublands which burned in wildfires in late 2023.
"We found that environmental water helped slow the decrease in floodwater levels that support mass waterbird breeding. There is also evidence of an increase in varieties of groundcover vegetation.
"Funded by the CEWH and working closely with the Narran Lakes Joint Management Committee, NSW National Parks and Wildlife Service and NSW Department of Climate Change, Energy, the Environment and Water, our research gives us a good foundation to learn more about the impacts of climate change in the coming decades.
"With the CEWH further funding its science program, Flow-MER - monitoring, evaluation and research - we look forward to continuing our vegetation research, collaborating with First Nations and growing our knowledge of the benefits of environmental water," she said.
