title: Functional Traits and Water Transport Strategies in Lowland Tropical Rainforest Trees.
abstract: Understanding how tropical rainforest trees may respond to the precipitation extremes predicted in future climate change scenarios is paramount for their conservation and management. Tree species clearly differ in drought susceptibility, suggesting that variable water transport strategies exist. Using a multi-disciplinary approach, we examined the hydraulic variability in trees in a lowland tropical rainforest in north-eastern Australia. We studied eight tree species representing broad plant functional groups (one palm and seven eudicot mature-phase, and early-successional trees). We characterised the species' hydraulic system through maximum rates of volumetric sap flow and velocities using the heat ratio method, and measured rates of tree growth and several stem, vessel, and leaf traits. Sap flow measures exhibited limited variability across species, although early-successional species and palms had high mean sap velocities relative to most mature-phase species. Stem, vessel, and leaf traits were poor predictors of sap flow measures. However, these traits exhibited different associations in multivariate analysis, revealing gradients in some traits across species and alternative hydraulic strategies in others. Trait differences across and within tree functional groups reflect variation in water transport and drought resistance strategies. These varying strategies will help in our understanding of changing species distributions under predicted drought scenarios.
authors.affiliation: Departamento de Ciências Florestais, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil; Centre for Tropical, Environmental, and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia.
authors.forename: Deborah M G
authors.initials: DM
authors.lastname: Apgaua
authors.affiliation: Centre for Tropical, Environmental, and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia.
authors.forename: Françoise Y
authors.initials: FY
authors.lastname: Ishida
authors.affiliation: Centre for Tropical, Environmental, and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia.
authors.forename: David Y P
authors.initials: DY
authors.lastname: Tng
authors.affiliation: Department of Science, Information Technology, Innovation and the Arts,Queensland Herbarium, Brisbane, Queensland, Australia.
authors.forename: Melinda J
authors.initials: MJ
authors.lastname: Laidlaw
authors.affiliation: Departamento de Ciências Florestais, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil.
authors.forename: Rubens M
authors.initials: RM
authors.lastname: Santos
authors.affiliation: School of the Environment, University of Technology, Sydney, New South Wales, Australia.
authors.forename: Rizwana
authors.initials: R
authors.lastname: Rumman
authors.affiliation: School of the Environment, University of Technology, Sydney, New South Wales, Australia.
authors.forename: Derek
authors.initials: D
authors.lastname: Eamus
authors.affiliation: Centre for Tropical, Environmental, and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia.
authors.forename: Joseph A M
authors.initials: JA
authors.lastname: Holtum
authors.affiliation: Centre for Tropical, Environmental, and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia.
authors.forename: Susan G W
authors.initials: SG
authors.lastname: Laurance
mesh_terms: D001315:Australia; D057231:Climate Change; D055864:Droughts; D008954:Models, Biological; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D018547:Plant Stems / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D018526:Plant Transpiration; D065947:Rainforest; D014197:Trees / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D014329:Tropical Climate; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water