Within-species variation suggests coordination between...
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Nested sampling of leaf and branch traits (1620 total branches) Within-species variation suggests coordination between increased hydraulic supply and tissue robustness across aridity gradients Leander DL Anderegg 1,2 Ian Markham, Xingwen Loy, Christina Elmer, Margie Mayfield 3 , Janneke Hille Ris Lambers 1 1 University of Washington 2 UC Berkeley 3 University of Queensland email: [email protected] twitter:@leanderegg website: ldlanderegg.weebly.com Background Intraspecific trait variation (ITV) can be large, and within- species trait-trait and trait-environment patterns do not always follow between-species patterns. However, our understanding of within-species trait variation is limited. We quantified within-species variation in leaf and branch traits across the aridity range of 8 tree species to 1. Quantify the dominant scale of trait variation for multiple common plant functional traits in multiple species 2. Assess the ubiquity of trait-environment relationship in a variety of climatic conditions 3. Test the coordination between tissue robustness and branch allometry within species. Results Implications • The extent of ITV varies considerably by species and trait and patterns of ITV remain difficult to explain. Between closely related species, the extent and dominant source of ITV defied easy characterization. Plasticity is usually large, but probably light-related not microclimate/edaphically related. • Though sometimes weak, there is typically coordinated acclimation/adaptation of leaf and stem tissue to increased drought stress across geographic aridity gradients in both mesic and xeric species, suggesting that drought stress at dry range boundaries is relative to species physiological capacity Data Traits Branch Leaf Area to Sapwood area Ratio (A l :A s ) Specific Leaf Area (SLA) Leaf Dry Matter Content (LDMC) Branch Wood Density (WD) 8 Species in Western Australia and Tasmania • 7 eucalypts & 1 acacia • 3 branches per individual • 5 individuals per plot • 3 plots per site • 4-5 sites per species (spanning species entire aridity range) 1. Amount and source of ITV are quite variable • Variaton btw plots at a site ALWAYS smallest variance component • Within-canopy plasticity typically large (especially in A l :A s but less so in WD) 2. Most species show predicted trait-environment relationships • Tissue robustness (WD, SLA, LDMC) increase with aridity, as does allocation to sapwood area over leaf area across a species aridity range, regardless of where that species lives • Almost all species showed significant trait-environment relationships with some aridity metric (PPT, PET, Moisture Deficit) for all traits (30/32 trait- environment relationships are significant) 3. Trait-Trait relationships suggest coordination between tissue robustness and tissue quantity. Trait covariation was often weak and only became apparent across multiple sites (not between plots or individuals), but almost universally suggested that shifts in allocation were coordinated with increased tissue robustness of both leaves and stems 0.30 0.40 0.50 0.60 0.5 0.6 0.7 0.8 LDMC WD 1.0 1.5 2.0 0.5 0.6 0.7 0.8 log.Al_As WD 1.0 1.5 2.0 0.30 0.40 0.50 0.60 log.Al_As LDMC Within Tree Within Plot Within Site Climate Variance in WD 0.000 0.002 0.004 0.006 Var in LDMC 0.000 0.001 0.002 0.003 0.004 A.acu E.sal E.mar C.cal E.ova E.vim E.amy E.obl Var in log(Al:As) 0.00 0.02 0.04 0.06 0.5 0.6 0.7 0.8 WD 20 40 60 80 SLA 0.30 0.40 0.50 0.60 LDMC 0 50 100 200 Al_As 400 600 800 1000 1200 1400 PPT (mm) Acknowledgements: Thanks to Mark Hovenden and Chuck Price for lending us lab space, and to HR Lai, J Park, E Sohlberg, and H Wauchope for field and lab assistance.
Transcript of Within-species variation suggests coordination between...
Nested sampling of leaf and branch traits
(1620 total branches)
Within-species variation suggests coordination between increased hydraulic supply and tissue robustness across aridity gradients
Leander DL Anderegg1,2 Ian Markham, Xingwen Loy, Christina Elmer, Margie Mayfield3, Janneke Hille Ris Lambers1
1 University of Washington 2 UC Berkeley 3University of Queenslandemail: [email protected] twitter:@leanderegg website: ldlanderegg.weebly.com
BackgroundIntraspecific trait variation (ITV) can be large, and within-species trait-trait and trait-environment patterns do not always follow between-species patterns. However, our understanding of within-species trait variation is limited.
We quantified within-species variation in leaf and branch traits across the aridity range of 8 tree species to
1. Quantify the dominant scale of trait variation for multiple common plant functional traits in multiple species
2. Assess the ubiquity of trait-environment relationship in a variety of climatic conditions
3. Test the coordination between tissue robustness and branch allometry within species.
Results
Implications• The extent of ITV varies considerably by species
and trait and patterns of ITV remain difficult to explain. Between closely related species, the extent and dominant source of ITV defied easy characterization. Plasticity is usually large, but probably light-related not microclimate/edaphically related.
• Though sometimes weak, there is typically coordinated acclimation/adaptation of leaf and stem tissue to increased drought stress across geographic aridity gradients in both mesic and xeric species, suggesting that drought stress at dry range boundaries is relative to species physiological capacity
Data
Traits Branch Leaf Area to Sapwood area Ratio (Al:As) Specific Leaf Area (SLA)
Leaf Dry Matter Content (LDMC)
Branch Wood Density (WD)
8 Species in Western Australia and Tasmania • 7 eucalypts & 1 acacia
• 3 branches per individual
• 5 individuals per plot • 3 plots per site • 4-5 sites per species
(spanning species entire aridity range)
1. Amount and source of ITV are quite variable • Variaton btw plots at a site
ALWAYS smallest variance component
• Within-canopy plasticity typically large (especially in Al:As but less so in WD)
2. Most species show predicted trait-environment relationships • Tissue robustness (WD, SLA,
LDMC) increase with aridity, as does allocation to sapwood area over leaf area across a species aridity range, regardless of where that species lives
• Almost all species showed significant trait-environment relationships with some aridity metric (PPT, PET, Moisture Deficit) for all traits (30/32 trait-environment relationships are significant)
3. Trait-Trait relationships suggest coordination between tissue robustness and tissue quantity. Trait covariation was often weak and only became apparent across multiple sites (not between plots or individuals), but almost universally suggested that shifts in allocation were coordinated with increased tissue robustness of both leaves and stems
0.30 0.40 0.50 0.60
0.5
0.6
0.7
0.8
LDMC
WD
1.0 1.5 2.0
0.5
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0.8
log.Al_As
WD
1.0 1.5 2.0
0.30
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0.60
log.Al_As
LDMC
Within TreeWithin PlotWithin SiteClimate
Var
ianc
e in
WD
0.000
0.002
0.004
0.006
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in L
DM
C0.000
0.001
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A.acu
E.sal
E.mar
C.cal
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E.vim
E.amy
E.obl
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in lo
g(A
l:As)
0.00
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PPT
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6080
PPT
SLA
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LDMC
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Al_As
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PPT (mm)
Acknowledgements: Thanks to Mark Hovenden and Chuck Price for lending us lab space, and to HR Lai, J Park, E Sohlberg, and H Wauchope for field and lab assistance.
