title: Dominant tree species are at risk from exaggerated drought under climate change.
abstract: Predicting the consequences of climate change on forest systems is difficult because trees may display species-specific responses to exaggerated droughts that may not be reflected by the climatic envelope of their geographic range. Furthermore, few studies have examined the postdrought recovery potential of drought-susceptible tree species. This study develops a robust ranking of the drought susceptibility of 21 tree species based on their mortality after two droughts (1990s and 2000s) in the savanna of north-eastern Australia. Drought-induced mortality was positively related to species dominance, negatively related to the ratio of postdrought seedlings to adults and had no relationship to the magnitude of extreme drought within the species current geographic ranges. These results suggest that predicting the consequences of exaggerated drought on species' geographic ranges is difficult, but that dominant species like Eucalyptus with relatively slow rates of population recovery and dispersal are the most susceptible. The implications for savanna ecosystems are lower tree densities and basal area.
authors.affiliation: School of Biological Sciences, University of Queensland, St Lucia, Qld, 4072, Australia.|Queensland Herbarium, Department of Science, Information Technology and Innovation, Brisbane Botanic Gardens, Mt Coot-tha Road, Toowong, Qld, 4066, Australia.
authors.forename: Roderick J
authors.initials: RJ
authors.lastname: Fensham
authors.affiliation: School of Biological Sciences, University of Queensland, St Lucia, Qld, 4072, Australia.
authors.forename: Josie
authors.initials: J
authors.lastname: Fraser
authors.affiliation: School of Biological Sciences, University of Queensland, St Lucia, Qld, 4072, Australia.
authors.forename: Harry J
authors.initials: HJ
authors.lastname: MacDermott
authors.affiliation: Queensland University of Technology, Science and Engineering Faculty, School of Earth, Environment and Biological Sciences, Brisbane, Qld, 4001, Australia.
authors.forename: Jenifer
authors.initials: J
authors.lastname: Firn
mesh_terms: D057231:Climate Change; D055864:Droughts; D065928:Forests; D011793:Queensland; D013045:Species Specificity; D014197:Trees / Q000502:physiology*
keywords: climate change; climate envelopes; drought-induced tree mortality; recruitment; resilience; savanna