A multi-species synthesis of physiological mechanisms in drought-induced tree mortality

H.D. Adams (1) , M.J.B. Zeppel (2) , W.R.L. Anderegg (3) , H. Hartmann (4) , S.M. Landhäusser (5) , D.T. Tissue (6) , T.E. Huxman (7) , P.J. Hudson (8) , T.E. Franz (9) , C.D. Allen (10) , L.D.L. Anderegg (11) , G.A. Barron-Gafford (12) , D.J. Beerling (13) , D.D. Breshears (12) , T.J. Brodribb (14) , H. Bugmann (15) , R.C. Cobb (16) , A.D. Collins (17) , L.T. Dickman (17) , H. Duan (18) , B.E. Ewers (19) , L. Galiano (20) , D.A. Galvez (5) , N. Garcia-Forner (21) , M.L. Gaylord (22) , M.J. Germino (23) , Arthur Gessler (24) , U.G. Hacke (5) , R. Hakamada (25) , A. Hector (26) , M.W. Jenkins (27) , J.M. Kane (28) , T.E. Kolb (22) , D.J. Law (12) , J.D. Lewis (29) , J.M. Limousin (30) , D.M. Love (3) , A.K. Macalady (31) , J. Martinez-Vilalta (32) , Maurizio Mencuccini (32) , P.J. Mitchell (33) , J.D. Muss (17) , M.J. O'Brien (34) , A.P. O\'Grady (32) , R.E. Pangle (8) , E.A. Pinkard (33) , F.I. Piper (35) , J.A. Plaut (8) , W.T. Pockman (8) , J. Quirk (13) , K. Reinhardt (36) , F. Ripullone (37) , M.G. Ryan (38) , A. Sala (39) , S. Sevanto (17) , J.S. Sperry (3) , R. Vargas (40) , M. Vennetier (41) , D.A. Way (42) , Chang Xu (17) , E.A. Yepez , N.G. Mcdowell (43)

1 DEPARTMENT OF PLANT BIOLOGY ECOLOGY AND EVOLUTION OKLAHOMA STATE UNIVERSITY STILLWATER USA
2 MACQUARIE UNIVERSITY DEPARTMENT OF BIOLOGICAL SCIENCE SYDNEY AUS
3 UNIVERSITY OF UTAH SALT LAKE CITY USA
4 MAX PLANCK INSTITUTE FOR BIOGEOCHEMISTRY JENA DEU
5 University of Alberta
6 Western Sydney University
7 UNIVERSITY OF CALIFORNIA IRVINE USA
8 The University of New Mexico [Albuquerque]
9 UNIVERSITY OF NEBRASKA LINCOLN USA
10 U.S. GEOLOGICAL SURVEY NEW MEXICO LANDSCAPES FIELD STATION LOS ALAMOS USA
11 UNIVERSITY OF WAHINGTON SEATTLE USA
12 University of Arizona
13 UNIVERSITY OF SHEFFIELD GBR
14 UNIVERSITY OF TASMANIA SCHOOL OF BIOLOGY HOBART AUS
15 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
16 UC Davis - University of California [Davis]
17 LOS ALAMOS NATIONAL LABORATORY EARTH AND ENVIRONMENTAL SCIENCES DIVISION LOS ALAMOS USA
18 INSTITUTE OF TECHNOLOGY NANCHANG CHN
19 UNIVERSITY OF WYOMING LARAMIE USA
20 SLU - Swedish University of Agricultural Sciences = Sveriges lantbruksuniversitet
21 UNIVERSITY OF COIMBRA PRT
22 NORTHERN ARIZONA UNIVERSITY FLAGSTAFF USA
23 U.S. GEOLOGICAL SURVEY FOREST AND RANGELAND ECOSYSTEM SCIENCE CENTER BOISE USA
24 Swiss Federal Research Institute
25 UNIVERSIDADE DE SAO PAULO PIRACICABA BRA
26 UNIVERSITY OF OXFORD GBR
27 UNIVERSITY OF CALIFORNIA SANTA CRUZ USA
28 HUMBOLDT STATE UNIVERSITY ARCATA USA
29 LOUIS CALDER CENTER FORDHAM UNIVERSITY ARMONK USA
30 CNRS - Centre National de la Recherche Scientifique
31 AGENCY FOR INTERNATIONAL DEVELOPMENT WASHINGTON USA
32 CREAF ESP
33 CSIRO HOBART AUS
34 ESTACIÓN EXPERIMENTAL DE ZONAS ÁRIDAS ALMERÍA ESP
35 CENTRO DE INVESTIGACIÓN EN ECOSISTEMAS DE LA PATAGONIA COYHAIQUE CHILE
36 IDAHO STATE UNIVERSITY POCATELLO USA
37 UNIVERSITA DEGLI STUDI DI BASILICATA POTENZA ITA
38 COLORADO STATE UNIVERSITY FORT COLLINS USA
39 UNIVERSITY OF MONTANA MISSOULA USA
40 UNIVERSITY OF DELAWARE NEWARK USA
41 RECOVER - Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience
42 DUKE UNIVERSITY NICOLAS SCHOOL ENVIRONMENT DURHAM USA
43 PACIFIC NORTHWEST NATIONAL LABORATORY RICHLAND USA

Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere–atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function

Mots clés: TREE MORTALITY; DROUGHT; CARBON STARVATION; NON STRUCTURAL CARBOHYDRATES; HYDRAULIC CONDUCTIVITY

Mots clés: HYDRAULIC FAILURE

Domaines: Sciences de l'environnement

H.D. Adams, M.J.B. Zeppel, W.R.L. Anderegg, H. Hartmann, S.M. Landhäusser, et al.. A multi-species synthesis of physiological mechanisms in drought-induced tree mortality. Nature Ecology & Evolution, 2017, 1, pp.7. ⟨10.1038/s41559-017-0248-x⟩. ⟨hal-02606468⟩