Jon Schurman PhD defense-PPFT

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


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


-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


Elevation

NPPR2 = 0.302

-0.535

0.343

0.215

-0.266

EvennessR2 = 0.2920.238

-0.440

Func. DivR2 = 0.286


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

Jon Schurman PhD defense-PPFT

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