Plasticity of the hydraulic system of beech
Living on the edge – how plastic is the hydraulic system of European beech in the face of climate change?
Bernhard Schuldt1, Florian Knutzen1, Sylvain Delzon3, Steven Jansen2, Hilmar Müller-Haubold1, Regis Burlett3, Yann Clough4 and Christoph Leuschner1
1
Plant Ecology, Albrecht von Haller Institute for Plant Sciences, Georg August University of Göttingen (
[email protected])
1 | Schuldt | XYLEME 2014
Plasticity of the hydraulic system of beech
European beech (Fagus sylvatica L.) - - - -
2 | Schuldt | XYLEME 2014
Widespread distribution in Europe Occurs in contrasting climatic areas Would naturally cover ~66% of Germany (Bohn et al. 2003) Currently, beech forms ~15% of German forests
www.euforgen.org
Plasticity of the hydraulic system of beech
Ongoing vital debate on the future of beech in the face of climate change Rennenberg et al. 2004, Ammer et al. 2005, Bolte et al. 2007, Geßler et al. 2007, Manthey et al. 2007, Czucz et al. 2011, Scharnweber et al. 2011, Rötzer et al. 2013
Main assumption: Beech will disappear from xeric sites in future Several traits are evidencing a high drought sensitivity of beech - - - -
Precipitation-sensitivity of radial growth Pre-senescent leaf shedding Drought-sensitivity of saplings Increased fine root mortality upon drought
But, some traits are pointing to a high tolerance of water shortage - High allocation plasticity - Regeneration potential after damage
High plasticity of the branch hydraulic system - Influence of water availability on vessel size - Comparable P50 from different provenances growing at the same site (Wortemann et al. 2011, EUFORGEN) 3 | Schuldt | XYLEME 2014
Plasticity of the hydraulic system of beech
Precipitation gradient in Northern Germany - Situated on sandy loam - Comparable age and structure
mm yr-1 1000
~300 mm gradient
800 600 400 200
820
765
690
670
610
545
0
Sellhorn Oerrel Klötze Göhrde Calvörde Unterlüß
4 | Schuldt | XYLEME 2014
Plasticity of the hydraulic system of beech
Influence of precipitation on biomass allocation along a precipitation gradient in Northern Germany
Precipitation-sensitivity of stem radial growth does not necessarily include a decline in Net Primary Productivity (NPP)
Most conclusion are only inferred from precipitation-sensitivity of radial growth
5 | Schuldt | XYLEME 2014
Müller-Haubold et al. 2013, Ecosystems 16, 1498-1516
Plasticity of the hydraulic system of beech
Along the gradient strong relation between fine root biomass, fine root productivity and precipitation
According to these two studies we expected significant adaptations of the branch hydraulic system and especially vulnerability to cavitation along the gradient
6 | Schuldt | XYLEME 2014
Hertel et al. 2013, Journal of Ecology 101, 1183-1200
Plasticity of the hydraulic system of beech
26 functional traits in total 11 6 6 3
wood anatomical hydraulic leaf growth-related
7 | Schuldt | XYLEME 2014
5 x 5 x 3-5 replicates (in total ~100 branches) site x tree x sample (sun-canopy)
traits
Abbreviation WD BA D Dh VD VI VG VS Tm A lumen : A xylem A xylem A cross A growth G dw KP KS KL P 12 P 50 P 88 A leaf SLA A xylem : A leaf C mass N mass δ 13 C
Unit -3
g cm yr µm µm
n mm-2 3 mm
nm % mm2 mm2 mm2 yr-1 kg m-1 kg m-1 MPa-1 s-1 -1 -1 -1 kg m MPa s -4 -1 -1 -1 10 kg m MPa s MPa MPa MPa cm2 cm2 g-1 10-4 m2 m-2 g kg-1 g kg-1 ‰
Definition Branch wood density Branch age Vessel diameter Hydraulically weighted vessel diameter Vessel density Carlquist's vulnerability index Vessel grouping index Solitary vessel index Thickness of intervessel pit membrane Relative vessel lumen area (lumen to sapwood area ratio) Branch sapwood area Branch cross-sectional area Annual branch sapwood area increment Branch growth rate Potential sapwood area-specific hydraulic conductivity Empirical sapwood area-specific hydraulic conductivity Empirical leaf area-specific hydraulic conductivity Water potential at 12% loss of hydraulic conductivity Water potential at 50% loss of hydraulic conductivity Water potential at 88% loss of hydraulic conductivity Average single leaf area Specific leaf area Sapwood to leaf area ratio (Huber value) Mass-related foliar carbon content Mass-related foliar nitrogen content Carbon isotope signature
Plasticity of the hydraulic system of beech
Hydraulic traits
Variable
P 1971-2000
WD
0.53
P 12
0.01
P 50
0.01
P 88
0.03
KS
0.16
KL
0.03
D
0.05
Dh
0.66
VD
0.12
VI
0.07
VG
0.41
VS
0.47
A lumen : A xylem
0.80
A leaf
0.09
A xylem : A leaf
0.32
SLA
0.11
C mass
