jon schurman phd defense-ppft
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From Plant Properties to Forest Function in Temperate Mixed Angiosperm-
Conifer Old Growth
Jonathan S. SchurmanPh.D. thesis defense
April 1st, 2016
Sitch et al. 2003. GCB Sakschewski et al. 2015. GCB
Temp thresholds, allometry, photosynthesis & mortality for 10 PFTs
Individuals assigned traits: interspecific correlations
2013
Demands: Hypothesis TestingImprove representation of structure
Feedbacks: Buffer or Amplify?
Link small-scale variation to scalable features
Leaf Economics Spec.
Wright et al. 2004. NatureBi
omas
s (M
g ha
-1)
NPP
(Mg
ha-1
yr—
1 )Ordonez et al. 2008 GEB Finnegan et al. 2015. J. Ecol
Mass Ratio Hyp.
(Grime 1998)Habitat Filtering
CommunityAssembly
EcosystemFunction
Trait Covariance
Drift & Disturba
nceAcclima
tion
Abiotic Composition
Factor Traits TaxonomyTotal 0.738 0.671
Topographic 0.035 0.014
Soil 0.002 0.009
Space 0.180 0.189
Topographic*Space 0.256 0.138
Soil*Space 0.093 0.101
Topographic*Soil 0.010 0.005Topographic*Soil*Space 0.162 0.215
41%5%
58%
1.5%
Variance Partitioning
Vital Rates Demographics Structure
f ( growth, mortality)
Acer saccharum
Tsuga canadensis
Fagus grandifoliaAcer rubrum
Abies balsamea
R2 = 0.25Mean D = 0.6 * Hmax + 3.0
Demographics &
Structure
Species Composit
ion
Abiotic Gradien
tsDrift &
Disturbance
Biomass Dynamic
s
Multiple RegressionSummary
TAGBR2 = 0.498
Func. CompR2 = 0.487
NPPR2 = 0.258
-0.698
-0.573
EvennessR2 = 0.280
Dens:DiamR2 = 0.234
Func. DivR2 = 0.345
Composition Stand Structure Biomass Dynamics
0.219
-0.422
-0.414-0.196
Abiotic
-0.588
0.141
-0.216
c. Df = 4, P = 0.466
0.309
-0.237
-0.221
-0.189
-0.084
-0.305
0.197
0.329
TAGBR2 = 0.72
LMA
GWC
NPPR2 = 0.37
Func. DivR2 = 0.679
Abiotic Composition Stand Structure Biomass Dynamics
X2 = 18.24; df = 13; P =0.149
NH4+
Hmax
Mean DR2 = 0.25
Nleaf
SuccessionStem Density
R2 = 0.60
HabitatFiltering
0.52-0.34
-1
0.19
0.19
0.34
0.62
-0.77
0.31
0.62
0.98
1.10
0.51
-0.98
0.81
11
Decay as an adaptation
Cornwell et al 2008 Ecology Letters
Data CollectionCWM = ∑i pi ti
tNleafLMANlitCN
1 Phase
Org. H2 Phase
Org1
Org2
Input
k =
k1 =
Org1
ΔOH = L – k*OH
If: ΔOH = 0Then: L = k*OHAnd: k = L/OH
Green traits Litter traits
Diversity Effects
𝐺=1−∑𝑖𝑝𝑖2
Multivariate distance
Scalability of small-scale observations:
Photo Credit: www.licor.com
Linking soil respiration to individual trees
Current photosynthesis drives soil respiration
Högberg et al 2001 Nature Tang & Baldocchi 2005 BGC
Tree-level effects
Hetero Auto
Root TraitsC Supply
Stem Diameter (cm)
Thomas 2010 Tree Phys.
Tobner et al. 2013 Frontiers Plant Sci.
Ontogeny
Closing Remarks
TAGB NPPDecaySoil
Respiration
AdaptationOntogeny
CWM & Func. Div
Population Structure
Acclimation?
The Great Lakes St. Lawrence
AcknowledgementsPeople who have had an impact on my degree (for better or worse)
Colleges & Other Peers Senior Researchers Advisory CommitteeAnna Almero Nate Basiliko John CaspersenAndrew Avsec Jing Chen Marie-Jose FortinJil Beezer Mike Drescher Benjamin GilbertMalcolm Cockwell Mike Fuller Adam MartinEric Davies Jen MurphyBen Filewod Rajit Patankar SupervisorSusan Frye KT Paw U Sean ThomasNigel Gale Tara SackettMatt Garmon Tom Shapland Haliburton ForestJeff Geddes Rick Snyder Peter SchliefenbaumAdam Gorglowski Udo von Toussaint CarmenJanise Herridge Julian Cleary PaulEmma Horrigan Jay Malcolm RayMark Horsburg Vic Timmer DaveMaciej Jamrozik Dave Martel Big RussJona Kowlick Alex "From France" Little RussKathleen Manson Mike Escobar Mill Manager Mike"Lunch Meat" Marney Issac PhilErin Mycroft The InternsPhil RudzTom SchikYannik SpillNoami "The French" Leo "The Peruvian Magician"Katlyn " The Mapper" Marc "The Toque"
Trait gradients and diversity effects predict litter decomposition in situ
Decay as Adaptation
Cornwell et al 2008 Ecology Letters
as Eco Func
• Organic horizon:• Major C sink– 2.9 kg C m-2 in OH – 9.5 kg C m-2 in
standing biomass Fahey et al. 2005, Frontiers
Evolution & Forest Function• FFs are the processes involved in exchange of matter and energy
between vegetation, soil and the atmosphere• Need to understand these at large scales to determine the role that
ecosystem play in buffering the Earth system against the consequences of increasing CO2
• DVGMs driven by models of rapid response plant physio (such as Farq and Shark 1982), parameterized as broad PFTs
• Lack of representation of the processes determining structural heterogeneity is a recognized issue– Habitat filtering– Succession– Lagged response of structure to change– Limited representation of diversity leads to extreme outcomes
Demands: Hypothesis Testing• Biometric data is need to test increasingly quantitative (trait-based) models
of assembly processes that contribute to heterogeneity in structure• Biometric data is severely limited by sampling
– Population/Community theory is needed to understand the extent of variation among biometric inventories (shown to improve regional FF predictions); large plots play an important role in understanding the extent of variation based on plot dimensions
– Niche vs. Neutral; exogenous (edaphic) vs. endogenous (succession)– Increased appreciation of feedback implies the need to investigate mechanisms
that can stabilize or accelerate structural dynamics– Need to understand role of biota and the randomness associated to ‘see through’
the randomness associated with small samples to translate from the data space to latent Ecosystem process
– Observations need to be linked to scalable features
TAGBR2 = 0.75
LMAR2 = 0.52
Elevation
GWC
NPPR2 = 0.46
Func. DivR2 = 0.50
Abiotic Composition Stand Structure Biomass Dynamics
X2 = 16.96; df = 23; P =0.053
NH4+
Hmax
R2 = 0.52
WDR2 = 0.60
SMR2 = 0.45 Stem Density
R2 = 0.62
Mean DR2 = 0.27
Nleaf
R2 = 0.37
TAGBR2 = 0.525Func. Comp
R2 = 0.540
Elevation
GWC
NPPR2 = 0.302
0.297
-0.535
-0.630
0.343
0.215
0.184
-0.146
-0.243
-0.266
EvennessR2 = 0.2920.238
0.251
Diam:DensR2 = 0.253
Func. DivR2 = 0.286
-0.144
0.155
-0.155-0.1810.198
0.430
Abiotic Composition Stand Structure Biomass Dynamics
-0.434
-0.577
-0.440
TAGBR2 = 0.525Func. Comp
R2 = 0.540
Elevation
GWC
0.184
-0.434
-0.146
-0.577
-0.243
EvennessR2 = 0.292
0.251
Diam:DensR2 = 0.253
Abiotic Composition Stand Structure Biomass Dynamics
Elevation
NPPR2 = 0.302
-0.535
0.343
0.215
-0.266
EvennessR2 = 0.2920.238
-0.440
Func. DivR2 = 0.286
Abiotic Composition Stand Structure Biomass Dynamics
Wood Density
Chave et al. 2009 Eco. Let. 12:351-366
Photo Credit: Sabrina Russo@ http://biosci.unl.edu/sabrina-russo
Seed size:
Wood Density (g cm-3)
Poorter et al. 2008 Ecology 89:1908-1920
f ( growth, mortality)
Data from Haliburton Forest
DBH (cm)Fr
eaky
Growth & Mortality
Coomes & Grime 2003 TREE 18:283-291
Sperry 2003 Evolution Func. Traits 164:115-127
Forest Function in N. America
Fahey et al 2009. Frontiers Ecol. & Env. 8:245-252
100-Year Eastern Deciduous Old Growth Pacific NW
g C m-2
g C m-2y-1
Hypothesis: acclimation vs. adaptation
Biomass Dynamic
s
Species Composit
ion
Abiotic Gradien
ts
(Nutrient Limitation)Acclimation Adaptation
Conservation of Evolved Tendency
Ecological
Drift
Demographics &
Structure
Species Composit
ion
Abiotic Gradien
ts
(Nutrient Limitation)Acclimation Adaptation
Conservation of Evolved Tendency
Ecological
Drift
Biomass Dynamic
s
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