Rapid appraisal links feral buffalo with kunkod (Melaleuca spp.) decline in freshwater billabongs of tropical northern Australia

Freshwater wetlands have great ecological, social, cultural and economic importance and are considered some of the most threatened ecosystems globally, especially in the tropics. In the tropics of northern Australia, much land is owned by Aboriginal people, thus requiring community-based approaches to monitoring and decision making. Herein we present a collaborative community-based rapid appraisal of an observed decline in a culturally and ecologically important tree genus of the freshwater wetlands in northern Australia, locally known as kunkod (Melaleuca spp., Myrtaceae) by Bininj (local Aboriginal people). We conducted collaborative research with the local Aboriginal Djelk Rangers incorporating local and scientific knowledge and preferred research methods. The decline in kunkod was more common in the water zone than in the mud and dry zones of freshwater billabongs in the Djelk Indigenous Protected Area. Kunkod decline and poor regeneration were significantly correlated with high water electrical conductivity, turbidity and ammonium. Feral buffalo activity was also positively correlated with these parameters, suggesting an indirect effect of buffalo on kunkod population health (large and small trees) through reduced water quality rather than direct rubbing on the trees, as was initially expected. Ongoing monitoring will allow assessment of potential recovery of kunkod following planned feral buffalo control.