Uncover the secrets of climate change by looking at the rings of a 566-year-old coolabah tree in the Gwydir Wetlands. Scientists are drilling into the bark of ancient trees to discover the hidden history of climate and water conditions. A recent study has revealed that some coolabahs and river red gums in the Gwydir Wetlands are over 500 years old. Researchers from the NSW Department of Climate Change, Energy, the Environment and Water (DCCEEW) and the University of Newcastle have used dendrochronology and radiocarbon dating to analyze the age and growth history of floodplain eucalypts. The oldest tree analyzed so far is a coolabah with a diameter of 176 centimeters, estimated to be 566 years old. This discovery is significant as it demonstrates the tree's resilience and survival over five centuries. However, the research has also uncovered previously unknown climate history affecting the Gwydir Wetlands. The growth ring patterns revealed past droughts, floods, and water availability, providing valuable insights into the region's environmental conditions. The study found that the reproduction of the trees is not a regular cycle, with six pulses where the trees successfully produce seeds. These 'mass recruitment events' are linked to major environmental and hydrological changes, such as those observed in the 1500s, 1600s, 1800s, and early 1900s. The research has important implications for environmental water management, as it highlights the need to deliver water to these floodplains to support the trees' maturation and reproduction. The findings will be included in the NSW government's Environmental Outcomes Monitoring and Research Program report. This groundbreaking project has shown that floodplain eucalypts hold tremendous potential for understanding past climate and water conditions in parts of Australia where long-term records don't exist. While similar research has been conducted in other areas with red river gums, this is the first time it has been done with coolabahs. The research could have beneficial impacts for other wetland areas, as it helps us understand the natural rhythm of rivers and reconstruct their history. This knowledge is crucial for effective environmental water management and ensuring the survival of these ancient trees for future generations.
