Impacts of Extreme Flooding on a Culturally Significant Tree Species: Minnarityi (Acacia cyperophylla F. Muell. ex Benth.) in Wangkumarra Country

Minnarityi (Acacia cyperophylla) is a native Australian tree that is of cultural significance to Indigenous Wangkumarra people. Its populations occur along drainage channels, where cyclical flooding likely shapes population dynamics. Climate change-driven changes in hydrological regimes could further alter these dynamics, yet baseline data on populationsin response to floods are lacking from this remote area of inland arid Australia. Here, we investigate the effects of a major flood on minnarityi population dynamics and site conditions across three sites. Pre- and post-flood field surveys assessed population structure, recruitment, mortality, plant condition, and soil characteristics. Subsequent germination experiments using seed collected post-flood explored potential constraints on recruitment. Following the flood, mortality increased and plant condition declined, particularly among seedlings. Despite generally high germination rates in laboratory settings after seed dormancy was broken, evidence of successful recruitment in the field was limited. This suggests that constraints during seedling emergence, establishment, or early survival may limit population recovery. Changes in flood frequency, magnitude, timing, and spatial distribution could shift the balance between mortality and recruitment for this culturally significant species. These findings highlight the need for integrated ecological and cultural approaches to minnarityi conservation and management under changing hydrological regimes.