DOI: 10.1111/gcb.13731
论文题名: Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees
作者: Powell T.L. ; Wheeler J.K. ; de Oliveira A.A.R. ; da Costa A.C.L. ; Saleska S.R. ; Meir P. ; Moorcroft P.R.
刊名: Global Change Biology
出版年: 2017
卷: 23, 期: 10 起始页码: 4280
结束页码: 4293
语种: 英语
英文关键词: Amazon rainforest
; drought
; plant hydraulics
; plant traits
; turgor loss point
英文摘要: Considerable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large-scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem-P50), leaf turgor loss point (TLP), cellular osmotic potential (πo), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought-tolerant versus drought-intolerant based on observed mortality rates, and subdivided into early- versus late-successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem-P50, TLP, and πo, but not ε, occurred at significantly higher water potentials for the drought-intolerant PFT compared to the drought-tolerant PFT; however, there were no significant differences between the early- and late-successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density—a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought-tolerant and drought-intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry-season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co-occuring drought-tolerant and drought-intolerant tropical tree species promises to facilitate a much-needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests. © 2017 John Wiley & Sons Ltd 资助项目: Moorcroft, P.R.
; Department of Organismic and Evolutionary Biology, Harvard UniversityUnited States
; 电子邮件: paul_moorcroft@harvard.edu
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60799
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States; Earth and Environmental Sciences Area, Lawrence Berkeley National Lab, Berkeley, CA, United States; Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, United States; Museu Paraense Emílio Goeldi, Programa de Pós-Graduação em Biodiversidade e Evolução, Belém, Pará, Brazil; Centro de Geociências, Universidade Federal do Pará, Belém, Pará, Brazil; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, United States; Research School of Biology, Australian National University, Canberra, ACT, Australia; School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
Recommended Citation:
Powell T.L.,Wheeler J.K.,de Oliveira A.A.R.,et al. Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees[J]. Global Change Biology,2017-01-01,23(10)