A description of Northern Pisonia grandis populations in Australia

Abstract

This report presents a review of Pisonia grandis forests on islands north of Townsville in the northern Great Barrier Reef, focusing on improving understanding of their distribution, ecological structure, condition, and associated threats. The review synthesises findings from rapid ecological assessments and desktop investigations to provide a regional overview of P. grandis ecosystems and the pressures influencing their resilience and long-term persistence. Pisonia grandis is a key ecological component of tropical island systems throughout the Asia-Pacific region, contributing to island stability, nutrient cycling, and the provision of important seabird nesting habitat. While southern Great Barrier Reef populations are relatively well documented, knowledge gaps remain regarding the trajectory, resilience, and vulnerability of northern populations, particularly in response to climate change and other threatening processes. The review examines the biogeographical distribution of P. grandis, the structure and composition of associated ecological communities, the condition of forests across the northern Great Barrier Reef, and the range of natural and anthropogenic threats affecting these habitats. In doing so, the report identifies key habitat functions provided by P. grandis forests and highlights current and emerging ecological pressures that may influence future management priorities. This work forms part of the Restoration of Reef Islands (RORI) Project, delivered through the Reef Joint Field Management Program by the Great Barrier Reef Marine Park Authority and Queensland Parks and Wildlife Service, and funded through the Australian Government’s Reef Trust administered by the Department of Climate Change, Energy, the Environment and Water. The project aims to support the rehabilitation, enhancement, and long-term resilience of island ecosystems within the Great Barrier Reef World Heritage Area through targeted management of known threats and improved understanding of ecological risk.