Above- and Below-ground Biomass and Soil

Organic Carbon Inventories of Willow Biomass

Crops Across a 19-year Chronosequence

Renato S. Pacaldo1, Timothy A. Volk1, Lawrence P. Abrahamson1,

and Russell D. Briggs1

1Department of Forest and Natural Resource Management, SUNY College of

Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210

Overview

Introduction

Methods

site selection and lay-out of sampling plots

belowground biomass

aboveground biomass

soil organic carbon

Results and Discussion

biomass accumulation pattern across a 19-yr chronosequence

on below- and above-ground biomass

above- and below-ground biomass ratio

soil organic carbon

Conclusion

Introduction

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

Willow biomass crops: low carbon fuel source 3.7 Mg CO2eqv ha-1 emissions over 7 rotations

499 Mg CO2eqv ha-1 accumulated in above ground woody biomass over 22 years

In willow production system……

Aboveground stool

biomass

Belowground biomass

Heller et al. (2003) LCA’s used shoot-root (S:R) ratio of 1.75, derived from

Matthews (2001) and Volk (2002), to estimate belowground biomass.

Shoot biomass: 13.6 odt ha-1 yr-1 from 3rd rotation data

No data

available

Most data focused on

aboveground biomass

Stems (stool) biomass

Very limited

data available

(belowground stool)

(fine roots)

(coarse roots)

Objectives

Inventory on above- and below-ground biomass

and soil organic matter (SOM) across a 5-, 12-,

14-, and 19- year old willow (SV1 - Salix

dasyclados) chronosequence.

– Variables measured

Biomass:

leaves, stems, and aboveground stool

fine root, coarse root, and belowground stool

total aboveground and total belowground

SOM in 15 cm increments to 45 cm soil depth

Determine shoot-root (S:R) ratio

Importance

Information on belowground biomass is

essential in the determination of GHG balances

and C dynamics

Inform the ongoing debate: high /low carbon fuel

source? Or carbon neutral? Or carbon sink?

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 for both sites

Soils

Tully: gravelly silt loam, well-drained; shallow bedrock

and fragipan

Lafayette: gravelly silt-loam; well-drained to moderately

poorly drained; shallow bedrock and fragipan

Topography

Tully: 0 % slope (flat)

Lafayette: 0-5 % slope (slightly rolling terrain

Climate: Both sites have mean annual precipitation of≈ 960 mm;

mean annual temperature ≈ 8 C

Study Sites

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4 m

5 m

Sampling Procedure

Taking samples for stem biomass

Leaf biomass, above- and below-ground stools biomasses

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Sampling Procedure

Take representative

plant within sampling

plot

Cut the

stool

Harvest leaves and stems

aboveground

stool

belowground

stool

same age across the four

willow fields because we cut

them at the same time

age: 6, 13, 15, and 20 years old

across four willow fields

Fine roots

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2 ft

2 ft

5 ft

3.5 ft

2 ft

sampling pit

Sampling Procedure

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

Sampling Procedure

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

Sampling Procedure

Results and Discussion

Salix dasyclados relative distribution of fine roots, coarse roots, and belowground stool across a 19-year

chronosequence

Age of Willow Crop (year)

4 6 8 10 12 14 16 18 20

Bio

mass P

roduction (

odt ha-1

)

0

2

4

6

8

10

12

14

16

18

Belowground Stool

Fine Roots

Coarse Roots

Salix dasyclados relative biomass distribution of foliage, stem,and aboveground stool. Stem biomass includes

a two-year growth accumulation.

Age of Willow Crop (year)

4 6 8 10 12 14 16 18 20

Bio

mass P

roduction (

odt

ha

-1)

0

10

20

30

40

50

Stem

Aboveground Stool

Foliage

Salix dasyclados total above- and belowground biomass productions. Stem biomass includes a two-year

growth accumulation

Age of Willow Biomass Crop (year)

4 6 8 10 12 14 16 18 20

Tota

l B

iom

ass P

roduction (

odt ha-1

)

0

10

20

30

40

50

60

70

Total Aboveground

Total Belowground

Below- and above- ground biomass ratio

Age (yr) Total Belowground

Biomass(kg/plant)

Total

Aboveground

Biomass(kg/plant)

Above:Belowgrou

nd Ratio

(R:S Ratio)

5 1.54a 1.43 b 0.95 ( 0.14) b

12 2.79b 2.00b 0.72 ( 0.10) c

14 2.29a 2.71a 1.18 ( 0.10) ab

19 2.33a 2.77a 1.23 ( 0.18) a

P values

n=24

<0.0001 <0.0001

Consistent with other studies on SR ratio:

1.40 (Volk, 2002) – for young Salix

dasyclados (SV1) clone

Age (yr) Stem:

aboveground

stool + total

belowground

Stem:total

belowground

Stem+foliage

:total

belowground

5 0.43a 0.54 a 0.69 a

12 0.26b 0.34b 0.43 b

14 0.53a 0.70a 0.83 a

19 0.53a 0.70a 0.86 a

Different ratios between stems and belowground

biomass across the four willow ages

Salix dasyclados Soil Organic Carbon (SOC)

100

120

140

160

180

200

Control 5 12 14 19

tota

l a

mo

un

t o

f S

OC

(M

g h

a-1

)

Age of Willow Crop (Year)

182 Mg ha-1

175 Mg ha-1

Previous reports 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).

Stand

Age

Above- and

Belowground

Stool Biomass

(Mg ha-1)

CO2 Eq.

Sequestration

(Mg ha-1)

5 6.81 ( 0.74) 12.48

12 15.09 ( 1.47) 27.66

14 20.71 ( 1.34) 37.97

19 20.99 ( 1.91) 38.48

Aboveground

Stool

Belowground

Stool

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

Adjustment of previous life cycle analysis….

ConclusionsTotal belowground biomass:

No statistically significant differences were detected

among 12-, 14-, and 19- year old stands

Biomass increases from 5 to12 years; stabilize onward

with slight variations.

Biomass production: 11 to 22 Mg ha-1 for 12- and 19-

year old stands, respectively.

Total aboveground biomass:

No statistically significant differences were detected

between stands: 14- and 19- yr old and 5- and 12-yr old

Biomass production: 10 to 21 Mg ha-1 yr-1 for 5- and 19-

year old stands.

total above:belowground (S:R) ratio increases

with age. S:R ratio of 0.53 could be used to

predict belowground biomass for mature willow

crop using the harvested shoots (stem) biomass

data

Steady state SOC across a19-year

chronosequence.

Our data suggest that SRC willow is not only a

source of renewable energy, but also a carbon

sequestration production system

Acknowledgment

This 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 for their help and support 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

And above all to our Almighty God!

Thank You!