Plant, Invertebrate and Pathogen Interactions in Kosciuszko National Park

Abstract

Kosciuszko National Park is the largest protected area in NSW and the only reserve in the State containing alpine vegetation. Diseases and pests of plants in the park are poorly known and, until recently, were thought to be benign and rare because of the cold climate. Surveys after the 2003 fire that burnt about 70% of the park detected dieback in both unburnt and regenerating burnt shrubs and trees. Since then, 36 species of Phytophthora have been identified in the park. Some perhaps do not persist but at least two (P. gregata and P. cambivora) are affecting the survival of two native shrub species. The fungus Armillaria luteobubalina also has been isolated from dying shrubs. Many insects and a mite have been identified on shrubs and trees in poor health. Although some of the invertebrate and disease syndromes are likely to be cyclic and natural, their interaction with climate change and invasive species may interrupt such cycles. One threatened species, Eucalyptus saxatilis, is in severe decline at some sites because of insect herbivory perhaps in conjunction with unusual climatic events. Climate change is also likely to allow the invasion or expansion of non-native and native pathogens and invertebrates with unpredictable consequences.