above- and below-ground biomass and soil organic carbon … · 2010. 11. 30. · objectives to...

Above- and Below-ground Biomass and Soil

Organic Carbon Inventories of Willow Biomass

Crops Across a 19-year Chronosequence

Renato S. Pacaldo*, Timothy A. Volk, Lawrence P. Abrahamson, and

Russell D. Briggs

Department of Forest and Natural Resource Management, SUNY College of

Environmental Science and Forestry,

1 Forestry Drive, Syracuse, NY 13210

8TH BIENNIAL SRWC OPERATIONS WORKING GROUP CONFERENCE

SHORT ROTATION WOODY CROPS IN A RENEWABLE ENERGY FUTURE:

CHALLENGES AND OPPORTUNITIES

OverviewOverview

IntroductionIntroduction

MethodsMethods

site selection and laysite selection and lay--out of sampling plotsout of sampling plots

belowground biomassbelowground biomass

aboveground biomassaboveground biomass

soil organic carbonsoil organic carbon

Results and DiscussionResults and Discussion

biomass accumulation pattern across a 19biomass accumulation pattern across a 19--yr yr chronosequencechronosequence

on belowon below-- and aboveand above--ground biomassground biomass

aboveabove-- and belowand below--ground biomass ratioground biomass ratio

soil organic carbonsoil organic carbon

ConclusionConclusion


Short Rotation Willow Biomass Crops:Short Rotation Willow Biomass Crops:

Carbon Neutral (Carbon Neutral (KeoleianKeoleian and Volk, 2005)and Volk, 2005)

OROR

Low Carbon Fuel?Low Carbon Fuel?


Previous Life Cycle Analysis (LCA) (Heller et al. 2003):Previous Life Cycle Analysis (LCA) (Heller et al. 2003):

Willow biomass crops: low carbon fuel source

3.7 Mg CO2eqv ha-1 emissions over the 22 year lifespan

499 Mg CO2eqv ha-1 accumulated in above ground woody biomass

over 22 years

IntroductionIntroductionMost studies focused on aboveground biomass

production

Limited data available on below ground biomass

Previous LCA estimate assumed belowground

biomass accumulation occurred over 3 rotations based

on harvested yield and shoot:root ratio of 1.75.

Why Important?

Belowground biomass is essential for determining

GHG balances and C allocation dynamics


On soil organic carbon (SOC)

Ulzen-Appiah (2002) reported no measurable

changes in soil C in willow coppice systems

production for 12 years.

SOC in hybrid poplar declined at early stage

(Hansen, 1993) and then increased after 5

years (Grigal and Berguson, 1998; Coleman et.

al., 2004).

Same pattern across a 19-yr chronosequence?

ObjectivesObjectivesTo inventory aboveTo inventory above-- and belowand below--ground biomass and soil ground biomass and soil

organic matter (SOM) across a 5organic matter (SOM) across a 5--, 12, 12--, 14, 14--, and 19, and 19-- year year

old willow (SV1 old willow (SV1 -- Salix Salix dasycladosdasyclados) ) chronosequencechronosequence. .

Variables measuredVariables measured

Biomass:Biomass:

leaves, stems, and aboveground stoolleaves, stems, and aboveground stool

fine root, coarse root, and belowground stoolfine root, coarse root, and belowground stool

total aboveground and total belowgroundtotal aboveground and total belowground

RootRoot--shoot ratioshoot ratio

SOM in 15 cm increments to 45 cm soil depth SOM in 15 cm increments to 45 cm soil depth

HH00: there is no significant difference in above: there is no significant difference in above-- and and

belowbelow-- ground biomass and soil organic carbon by age.ground biomass and soil organic carbon by age.

Planted

1995

Planted

1990

Planted

2004

Study Sites

3 sites at Tully and 1 site at Lafayette, NY

Planted

1997

6 plots/ site

Site characteristics

Tully:

Soil: gravelly silt loam, well-drained

High Meadows, Lafayette Road

Soil: gravelly silt loam, well-drained to somewhat

poorly drained

shallow bedrock and fragipan in some locations

MAP ≈ 960 mm

MAT ≈ 8 C

Study Sites

SpeciesSpecies

Salix Salix dasycladosdasyclados (SV1)(SV1)

5-year old willow crop 19-year old willow crop

During inventory period, the stems had been

growing for two years since the last cutting

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4 m

5 m

Sampling ProcedureSampling Procedure

Taking samples for stem biomass

Leaf biomass, above- and below-ground stools biomasses

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Take representative

plant within sampling

plot

Cut the

stool

Harvest leaves and stems

aboveground

stool

belowground

stool

Fine roots

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2 ft

2 ft

5 ft

3.5 ft

2 ft

sampling pit


composite soil samples

for fine root biomass

hand pick the fine roots and

oven-dry at 65 C for 15 days

Fine roots

Sampling depth: 45 cm in 15

cm interval

Coarse roots (> 2 mm diameter)

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3.5 ft

2 ft


Soil organic matter (SOM) in 15cm increments

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4 m

5 m

soil sample for total

SOM determination

by loss on ignition

(LOI)

measure coarse

fragment volume2 mm sieve


Statistical AnalysisStatistical Analysis

ANOVA to find out significant difference of ANOVA to find out significant difference of

biomass and SOC by age classesbiomass and SOC by age classes

if the results are significantly different, if the results are significantly different,

treatment means are compared by Least treatment means are compared by Least

Significant Difference (LSD) test.Significant Difference (LSD) test.

univariateunivariate procedure procedure –– for testing normal data for testing normal data

distributiondistribution

Leven’s test Leven’s test –– for testing homogeneity of for testing homogeneity of

variancevariance

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

5-yr old 12-yr old 14-yr old 19-yr old

Mg

ha

-1

Salix dasyclados belowground biomass

Belowground Stool

Coarse Roots

Fine Roots

Results and DiscussionResults and Discussion

Salix dasyclados stem & leaf biomass

(annual yield)

0

5

10

15

20

25


Mg

ha

-1yr-

1

leaf biomass

stem biomass

17.6

7.2

2.63.3

Salix dasyclados aboveground stool

biomass (total yield)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0


Mg

ha

-1

4.8

10.2

Salix dasyclados above- and belowground

biomass (total yield at time of inventory)

0

10

20

30

40

50

60


Mg

ha-1

belowground biomass

aboveground biomass

22 Mg ha-1

13 Mg ha-1

48 Mg ha-1

21 Mg ha-1

Below- and aboveground biomass ratio

Age (yr) Total Belowground

Biomass(kg/plant)

Total Aboveground

Biomass(kg/plant)

Below:Above-

ground Ratio

(R:S Ratio)

19 2.33a (0.37) 4.24a (0.24) 1:1.82

14 2.39a (0.10) 4.39a (0.49) 1:1.83

12 2.88a (0.28) 2.93b (1.06) 1:1.02

5 1.48b (0.11) 2.16 b (0.46) 1:1.46

P values

n=24

<0.0001 <0.0001

Consistent with other studies on SR ratio:

1.75 (Heller et al 2003)

1.40 (Volk, 2002) – for young Salix

dasyclados (SV1) clone

The higher SR ratio (i.e 1.8) in Tully compared to Lafayette

site (1.0) could be attributed to the differences in site quality

Tully Study Sites (Age 5, 14, 19) Lafayette Study Site (Age: 12)

Age Bulk density in

30-45 cm depth

(g/cm3)

5 1.3 -1.6

12 1.5 - 1.7

14 1.3 - 1.4

19 1.0 - 1.2

In poor site, about

60% of NPP is used

to develop short-live

roots (Reyes et al.,

1981)

Salix dasyclados Soil Organic Carbon (SOC)

100

120

140

160

180

200

0-yr old 5-yr old 12-yr old 14-yr old 19-yr old

Mg

ha

-1

182 Mg ha-1

175 Mg ha-1

Age


SO

C (

Mg

ha-1

)

0

20

40

60

80

100

120

0-15 cm

15-30 cm

30-45 cm

Salix dasyclados Soil Organic Carbon (SOC) by Depth

SOC in this study is consistent with some

previous reports:

No detectable changes in microbial biomass

carbon (labile carbon) in SRWC across a 12-yr

chronosequence (Ulzen-Appiah, 2002)

SOC declined at early stage (Hansen, 1993)

and then increased after 5 years (Grigal and

Berguson, 1998; Coleman et. al., 2004).

SOC in SRWC poplar ranged from 20 to more

than 160 Mg ha-1 (Coleman et al., 2004).

LCA Results from Heller et al. (2003)

CO2

(Mg CO2

ha-1)

Other GHG

(Mg CO2

eq ha-1)

Total

(Mg CO2

eq ha-1)

Emissions

Diesel fuel 3.1 0.1 3.2

Agr Inputs 2.9 0.4 3.4

N2O from N fertilizer 3.9 3.9

N2O from foliage 7.3 7.2

C Sequestration

Below ground -14.1 -14.1

Soil C 0 0

Net Total -8.0 11.7 3.7

Harvested Biomass -499.2 -499.2

3.2

7.2

3.4

3.9

Current Study

CO2

(Mg CO2 eq

ha-1)

-38.5

0

-20.8

Estimates of GHGs gas flows per hectare of willow plantation,

accumulated over 7 rotations

ConclusionsConclusionsThere is significant difference in total belowground biomass There is significant difference in total belowground biomass

across a 19across a 19--year year chronosequencechronosequence

increases until about age 12, and stabilize onward with slight increases until about age 12, and stabilize onward with slight

variations. variations.

No significant difference in belowground stool biomass between No significant difference in belowground stool biomass between

ages 5ages 5-- and 12and 12-- year old and between ages 14year old and between ages 14-- and 19and 19--year old year old

SRWC plantation.SRWC plantation.

Aboveground biomass is significantly different across the Aboveground biomass is significantly different across the

chronosequencechronosequence and increases with age. and increases with age.

No significant difference in SOC across a19No significant difference in SOC across a19--year year

chronosequencechronosequence . .

Limitation of this study: site quality confounded the effects of Limitation of this study: site quality confounded the effects of

age as shown in Lafayette site. Variation of site quality is one of age as shown in Lafayette site. Variation of site quality is one of

the major sources of error in the major sources of error in chronosequencechronosequence studies (studies (YanaiYanai et et

al., 2000).al., 2000).

AcknowledgmentThis study was carried out with the funding support

from USDA Rural Development through Timothy A.

Volk and Lawrence P. Abrahamson.

We wish to thank the following people for their help during the

data collection

Project Staff:

Rebecca Allmond, Eric Fabio, Philip Castellano, and Ken Burns

Student Assistants:

Jacob Bakowski, Tyler Harvey, Gabe Kellman, Jason Maurer,

Ryan Newby, and Devin Mc Bride

Thank You!

above- and below-ground biomass and soil organic carbon … · 2010. 11. 30. · objectives to...

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