Sub-project 3: Soils vs Climate ChangeSoils vs Climate ChangePaul Nelson (JCU)Paul Nelson (JCU)

� Soil pit was installed in mid 2007� 3 Depths 0.1m, 0.75m, 1.5m� Sensors:

Temperature (thermocouple)Water content (TDR probes)Water potential (Gypsum blocks)

� Vacuum systemUsed to collect water infiltrating throughthe profile for measuring DOC movement

SOIL CHARACTERISTICSSOIL CHARACTERISTICS� Cape Tribulation: water availability is likely then to be the key driver of productivity in these seasonally dry rainforests. A sensor pit was dug, initially by hand!� Rock : Soil ratio : around 40%

Data Logger

0.1m

0.75m

1.5m

1.5m

0.1m

1m

1m

Water samplerGB Heavy TDR probe

SUBSUB--SURFACE STORAGESURFACE STORAGEWater storage

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SUBSUB--SURFACE FLUXESSURFACE FLUXESWater uptake

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WATER UPTAKE VS DEPTHWATER UPTAKE VS DEPTH

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(m3/

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0.1 m0.75 m1.5 mSoil profile

Wet soil:Greatest water extraction from topsoil(most negative change in water content)

Dry soil:Least water extraction from topsoil

WATER UPTAKE GROUNDWATERWATER UPTAKE GROUNDWATER

� Installed 3 bores to measure uptake from groundwater

�Bedrock at 12-33 m depth

�Watertable at 10-13 m depth (July 2008- April 2008)

�Marc Le Blanc (JCU) is in chargeof this part of the sub-project.

PHENOLOGY CRANEPHENOLOGY CRANE

�Phenological events are recorded monthly using the crane which began in Jan 2009

�Budding, flowering and fruiting events are recorded as presenceor absence.

� Phenocam is being installed in 2 months time.

PHENOCAMPHENOCAM (T23(T23--24)24)

Jan 09 Feb 09

Mar 09 Apr 09Sony DSLR α-700 tried Sony video

FOREST PRODUCTIVITYFOREST PRODUCTIVITYCape Tribulation above ground productivity

� Dendrometry: 171 trees have been banded.� Litter: 25 traps have been monitored fortnightly.

LEAF LITTERLEAF LITTER --FALLFALL25 permanent litter traps on one hectare grid

Leaf Litter FallLeaf Litter Fall

Leaf Litter Fall

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25

0 4 8 12 16 20 24 28 32 36 40 44 48 52

Weeks of the Year

Rat

e as

2 w

eek

Ave

rage

Ton

nes/

Ha/

Yr

2007

2008

Average for 20076.1 t/ha/yr

Average for 2008

6.5 t/ha/yr

Total Litter FallTotal Litter Fall

Total Litter Fall 2007

12.35 tonne/ha/yr

Total Litter Fall 2008

10.97 tonne/ha/yr

Woody material 35% 2007 21% 2008

SPATIAL SAMPLING OF C SPATIAL SAMPLING OF C POOLSPOOLS

� Spatial samplingdesign at Tumb. Ensured measurementsare comparable withthe source area of theflux tower.� Stratified, randomdistance weighted fromtower with 30 permanentplots.

BUDGET OF C POOLSBUDGET OF C POOLS

� Total C budget for this forest ecosystem is quite high at nearly 500 tC/ha.� But nothing likethe forest of Jason’s!

1

363

soil

aboveground biomass

understoreylitter

woody debrisfine roots

coarse roots

Total 483 tC / ha

BIOMASS C BUDGETBIOMASS C BUDGET

� Proportion of roots is small which follows for aforest on deep fertile soils and high rainfall.

stemwood

bark

branches

twigs leaves

roots

root bole

< 2 mm

2-5 mm

5-20 mm 20-50 mm

> 50 mm

RootsTotal biomass

understorey

ALLOMETRYALLOMETRY� Allometric equations are used to expand from readily measureable quantities (dbh, height, density) to the above ground biomass for the plot. Hypsometersseem to be the best for height.� This can then be converted to tC/Ha.� The difficulty in developing allometric equations is that it requires harvesting of whole trees – or a canopy crane.

THE CRANETHE CRANE� Measurements were made ofeach component of the AGB,these were then summed to provide an estimate for the treeand then replicated to provide dataused to develop a species equation.

Species (kg)Stem biomass (%) Crown biomass (%) Tree biomass (σσσσ)

Alstonia scholaris 90 10 246 (215)

Cleistanthus

myrianthus

69 31 244 (118)

Myristica insipida 80 20 226 (138)

Acmena graveolens 83 17 1161 (1168)

Endiandra microneura 64 36 791 (708)

Normanbya normanbyi 96 4 145 (46)

ALLOMETRY IIALLOMETRY II� Species specific allometric equationsalong with general species equations allowed calculation of site AGB = 270 t ha-1

y = 2.5636x - 2.7428

R2 = 0.9791

y = 2.4937x - 2.3191

R2 = 0.9874

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2 3 4 5

LN b

iom

ass

(kg)

LN DBH (cm)

Brindabella

Tumbarumba

Aboveground biomass

Eucalyptus delegatensis

� Dendrometer bands were placed on 171 trees with DBH >25cm in March 2007

� DBH = at 1.30m above forest floor.

� Growth rates in year 2007/8 ranged from 0 to 8cm increase in circumference.

� Census intervalon dbh plot isevery 5 years.

DENDROMETRYDENDROMETRY

Highly variable crown cover and LAI over one hectare plo t

(Three of the 25 canopy fish-eye images taken at litter trap sites in April 2008)

LAI HIGHLY VARIABLELAI HIGHLY VARIABLE

AFTER CYCLONE RONASignificant damage occurred to the canopy structure.

�in particular the vinestowers were knocked to the ground.

�large amounts of debristrees were carried to the forestfloor.

�Light penetration changedconsiderably.

GRANIER: SAP FLOW SYSTEMGRANIER: SAP FLOW SYSTEM(THERMAL DISSIPATION)(THERMAL DISSIPATION)

UP GmbH System Germany•• The The constant currentconstant current power supply power supply heats the top needle electrode.heats the top needle electrode.1212--14 V DC supply. 14 V DC supply. •• ∆∆∆∆∆∆∆∆T measured between top and bottom T measured between top and bottom electrodes. electrodes. •• Sap velocitySap velocity inversely proportional to inversely proportional to ∆∆∆∆∆∆∆∆TT⇒⇒⇒⇒⇒⇒⇒⇒ calculate the calculate the sap flux densitysap flux density UUvv•• ∆∆∆∆∆∆∆∆TToo measured when no sap flux.measured when no sap flux.

Uv = 0.000119*Z1.231 [m3 m-2 s-1]

Z = ( )

T

TTo

∆∆−∆

Q = ρs*uv*Asw [kg s-1]

GRANIER: SAP FLOW SYSTEMGRANIER: SAP FLOW SYSTEMDATADATA

fig.3: sap flow density 15.01.03

0

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14 14.16666667 14.33333333 14.5 14.66666667 14.83333333 15

hrs

ml/c

m²/

min

E. microneura (3008) W. laevis (4003) M. insipida (4014) M. insipida (4008)

S. sayeri (3009) C. australe (4006) A. scholaris (4012) D. papuanum (4022)

fig.5: sap flow density 22.08.03

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42 42.16666667 42.33333333 42.5 42.66666667 42.83333333 43

hrs

ml/c

m²/m

in

E. microneura (3008) W. laevis (4003) M. insipida (4014) M. insipida (4008)

S. sayeri (3009) C. australe (4006) A. scholaris (4012)

TRUNK HEAT BALANCE: TRUNK HEAT BALANCE: SAP FLOW SYSTEMSAP FLOW SYSTEM

•• The power supply The power supply currentcurrent is is proportional to the sap flowproportional to the sap flow( 40 ( 40 -- 200 mA)200 mA)••1212--14 V DC supply is converted 14 V DC supply is converted to to 1kHz1kHz AC which is supplied at AC which is supplied at constant powerconstant power (0.6W) by (0.6W) by top 3 electrodes. top 3 electrodes. •• T on 3 electrodes measured T on 3 electrodes measured relative to T on bottom electrode.relative to T on bottom electrode.

EMS-51 System, Czech Republic

Qcm =ww c

z

dTdc

P −**

[kg s-1 cm-1]

= 0.000125*Usig[mV]- Qidle [kg h-1 cm-1] Qtree = Qcm*(A - 6.28*B) [kg/hr]

TRUNK HEAT BALANCE: TRUNK HEAT BALANCE: DATADATA

DOY 2008

160 162 164 166 168 170 172

Sap

flow

(g

cm-1

h-1

)

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25

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75

Argyrodendron peralatumSyzygium sayeriAechmena graveolensCastanospermum australe

Eva

pora

tion

(mm

)

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312 314 316 318 320 322 324 3260

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60 Ae graveolens Sy sayeri Ca australe My insipida Ca australe Cr grandis

DOY 2009

190 191 192 193 194 195 196 197 198 199 200

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80 C australis M insipida S sayeri C grandis

PHOTOSYNTHETIC PARAMETERSPHOTOSYNTHETIC PARAMETERS

Peter FranksPlant, Cell and Environment(2006) 29, 584–592

TRUNK HEAT BALANCE: TRUNK HEAT BALANCE: DATA IIDATA II

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M J J A S O N D J F M A M J J A S

2008 2009

Tra

nspi

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m d

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T (°C)

Sa

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•• Scaled from tree to stand.Scaled from tree to stand.

Sapflow can be analysed in terms of environmental drivers.

TRUNK HEAT BALANCE: TRUNK HEAT BALANCE: DATA IIIDATA III

•• D. McJannet et al. D. McJannet et al. Hydrol. Process. 21 (2007) 3473.• Trunk Heat Balance : Annualtranspiration around 540mm• Eddy flux LE Eddy flux LE 4.8mm d4.8mm d --11. . evapotransp. evapotransp. 1752mm y1752mm y --11

•• Extended dry period from July Extended dry period from July through to October precipitation through to October precipitation input < 4mm day.input < 4mm day.•• Mean water uptake from theMean water uptake from thesoil was between soil was between 2 2 -- 4 mm 4 mm dd --11..

HEAT PULSE:HEAT PULSE:SAP FLOW SYSTEMSAP FLOW SYSTEM

D. McJannet & P. FitchCSIRO Land and Water Technical Report No. 39/04• sap flow is measured by determining the velocity of a short pulse of heat carried by the moving sap stream.

• Sap flow velocities are calculated and converted tovolumetric sap flow.• A commercial example is Greenspan Technology (Qld) : Lindsay Hutley, Derek Eamus