Transcript Slide 1

Department of Plant, Soil and Environmental Sciences
Thesis Defense Seminar
Soil Drainage Class Influences
on
Soil Organic Carbon
in a
New England Forested Watershed
Jay Raymond
M.S. Student
Acknowledgements
Committee:
Dr. Ivan J. Fernandez, Professor of Soil Science, Advisor
Dr. Tsutomu Ohno, Professor of Soil Chemistry
Dr. Kevin Simon, Associate Professor of Biological Sciences
Funding:
Plant, Soil, Environmental Sciences
Maine Agricultural & Forest Experiment Station
Seminar Overview
• Introduction
- Why?
- Terrestrial C Cycle
- Soil Drainage Classes
- Wetland Soils
- Forest Types
• Hypotheses
• Methods & Results
- Site Location & Description
- %C & C Content
- C Fractions (Active, Stable, Passive)
- Soil Respiration (RS)
• Conclusions
The Pedosphere Focus
Lal, Kimble, and Follett, 1997
Why Study Carbon?
tececo.com/sustainability.role_soil_sequestration.php
C Emissions
Sources
Sinks
carboncycle.aos.wisc.edu/land-uptake/
Sources
boston.com
Sinks
thew2o.net/
cargurus.com
teara.govt.nz/en/atmosphere/1/1
oregrinder.com
Soil Organic Carbon (SOC)
NRCS
Kern, 1994; Johnson and Kern 2003; Amichev, 2003
Soil Drainage Classes – NRCS (8)
I
N
C
R
E
A
S
I
N
G
W
E
T
N
E
S
S
Excessively Drained (ED)
Somewhat excessively drained (SWED)
Well drained (WD)
Moderately well drained (MWD)
Somewhat poorly drained (SWPD)
Poorly drained (PD)
Very poorly drained (VPD)
Subaqueous (?)
soils.usda.gov/technical/handbook/contents/part618.html; Soil Survey Manual Ch. 3, MAPSS 2010
Maine Soil Drainage Classes
Well
20%
Excessively
3%
Moderately Well
25%
Very Poorly
10%
Somewhat Poorly
19%
Somewhat
Excessively
3%
Poorly
20%
Source: NRCS
Wetland (Hydric) Soils
nesoil.com/images/images.htm
-
faculty.msmary.edu/envirothon/current/guide/soil_features_part_1.htm
Histosol
- Mineral
- > 40 cm (16”) O.M.
- VPD
nesoil.com/images/images.htm
Histic epipedon
- Mineral histic
-
- VPD – PD
- PD
Hypotheses
soil wetness increases, SOC increases
(decreasing drainage)
•
%C, C content
- PD > SWPD > MWD
- CF > BLD
•
C Fractions
- Passive: MWD > SWPD > PD
- Passive: BLD > CF
• RS
- MWD > SWPD > PD start of season
- SWPD > PD > MWD end of season
- SWPD > MWD entire season
Site Location
Bear Brook Watershed in Maine (BBWM)
Soil
Drainage
Forest
Types
Site Description
Rock Outcrop
Abram
CF
Lyman
Tunbridge
Lyman
Tunbridge
Abram
Marlow
Lyman
Lyman
Marlow
Tunbridge
Tunbridge
Berkshire
Lyman
Marlow
Dixfield
Tunbridge
Dixfield
Colonel
• red
eastern
spruce
hemlock
• balsam
northern
firwhite
cedar
• red spruce
Colonel
Brayton
SWPD
MWD
PD
Brayton
Brayton::
Colonel
Tunbridge:
Peacham
loamy, mixed,
active,
isotic, frigid,
coarse-loamy,
nonacid,
frigid, shallow
shallow
isotic,
frigid,
Aeric
Endoaquepts
Aquic
Haplorthods
• American
sugar maple
yellow
birch
beech
• red
sugar
paper
maple
maple
birch
• sugar
paper maple
yellow
birch
birch
Typic Haplorthods
Dixfield:
coarse-loamy,
isotic, frigid,
Aquic Haplorthods
BLD
BLD
Parent Material:
Adapted from : NRCS, Franklin County, ME Soil Survey
non-calcareous compact Wisconsinan age basal till dominated by
mica schist, phyllite, granite and gneiss
Elevations:
165 - 470 m
Aspect:
Southeasterly
Slopes:
Higher: steeps/benches, 31% avg.
Lower: gentler, 15%. avg.
Experimental Design
Soil Drainage & Forest Type
Soil Drainage Classes (3)
MWD (6)
CF
BLD
SWPD (6)
CF
BLD
PD (6)
CF
BLD
Plot Design
15 m
71 cm
RS ,TAIR, TSOIL, GSM
- Monthly, May-Nov.
HWEC:
O horizon, 0-5 cm
(late May, July, late October
15 m
Quantitative Excavations
O horizon
0-5
5-25
25-50
50-C
C
Digging
Weighing
Sieving
Canary et al., 2000
Sample Processing
•
•
•
•
Greenhouse drying (1-2 weeks)
Sieving, weighing, moisture content
Soil physical-chemical analysis
%C
Total Soil C Content Calculation
%C
100
*
oven dry fine earth
increment mass
(kg ha-1)
=
1000 kg ha-1 = 1 Mg ha-1
Total C
of
Increment
(kg ha-1)
Statistical Analysis
• Statistical analysis conducted with R
• Levene Test for homogeneity of variance
• Shapiro-Wilk normality test
• Analysis of Variance (ANOVA)
- %C, C Content, C Fractions
- Tukey HSD multiple comparison of means
• Repeated measures ANOVA
- Rs
• Significant differences reported p < 0.05
C Concentration (%C)
50
Soil Drainage Class
Forest Type
A
40
A
A
A
A
%C
30
20
10
a
0
M
O
MWD
M
O
SWPD
a
b
b
M
O
PD
O
M
CF
a
O
M
BLD
%C with Depth – Soil Drainage
O Horizon
0-5 cm
5-25 cm
25-50 cm
MWD a
SWPD b
b
PD
50-C
C
0
10
20
%C
30
40
%C with Depth – Forest Type
O Horizon
0-5 cm
5-25 cm
25-50
50-C
CF
BLD
C
0
10
20
%C
30
40
50
C Content
400
Soil Drainage Class
Forest Type
A
a
-1
C (Mg ha )
300
A
a
200
a
B
a
AB
a
a
a
a
B
100
a
a
a
ab
b
0
MWD
SWPD
?
PD
N.a.N.
CF
BLD
Summary
SOC was different
- among soil drainage classes, but not as expected
- forest types
• O Horizon: NSD
• Mineral Soil
- MWD > SWPD, PD
• Entire Soil (O horizon + mineral)
- Drainage: MWD > PD
- Forest : CF > BLD
Why?
• Greater ecosystem productivity – belowground
- roots: MWD > PD
- numerical data from QP
- qualitative pedon descriptions effective rooting depth
C Fractionation
Mineral Soil
Active
• labile, or active (< 2 yrs)
Stable
• intermediate (>2 - < 100’s yrs)
Passive
• recalcitrant, extremely resistant C (>100’s yrs)
(Stevenson, 1994; Boyer and Groffman, 1996; Zsolnay, 2003) (Leavitt et al., 1996; Paul et al., 2006; D’Angelo et al, 2009) (Martel and Paul, 1974; Sollins et al.,1999; MacLauchlan and Hobbie, 2004)
C Fractionation – Sequential Extraction
Active C Fraction – HWEC
-
(Ghani et al. 2003; D’Angelo et al. 2009)
Air dry soil in 50 ml tubes: 1:10 for O horizon, 1:2 mineral
Tubes in 80˚C for 16h
0.4 µm polycarbonate filters
Measure TC w/ Shimadzu TOC 5050
Oven dry residue overnight
Passive Fraction – Acid Hydrolysis (Sollins et al., 1999; D’Angelo)
- 1 g soil w/ 6 M HCl. 1:20 organics, 1:10 mineral
- Refluxed for 16 hrs in digestion tube at 116◦C
- Filtered through Whatman no. 50
- Oven dry residue overnight, send to lab for %C
Stable Fraction =
(%C Original Sample) - (Passive %C) – (Active %C)
C Fractions
Proportion of Total C
Stable C Fraction
69%
Active C Fraction
< 1%
Passive C Fraction
31%
Fig. 4. Overall mean of the mineral soil for the active, stable, and passive C fractions
across all soils in this study.
C Fractions - %C
6
MWD
SWPD
PD
a
5
4
%C
a
3
b
b
2
b
b
1
a
b b
0
Passive
Stable
Soil Organic Carbon Fraction
Active
C Fractions – C Content
250
MWD
SWPD
PD
CF
a
200
BLD
-1
C (Mg ha )
a
150
100
a
a
b
a
a
50
b
b
a b b
b
a a
0
Passive
Stable
Active
Why?
• Similar aerobic conditions in upper soil horizons
March
April
Zone of saturation
Seasonal HWT
May
June
July
August September
Zone of saturation
Seasonal HWT
October
November
Zone of saturation
Seasonal HWT
Soil Respiration (Rs) Methods
• Collars installed March-April 2010 (5” PVC pipe)
• Monthly measurements w/ Li-Cor 6400-09
- May-June until Oct.-Nov.
• Total 72 collars for this study – 3 days
- (4/plot * 3 plots/drainage * 2 forest types)
- 3 days of measurement
- measurements 8am-1pm
• Additional variables measured
- Gravimetric soil moisture (GSM) - O & 0-5 cm
- Air temp (TAIR)
- Soil temp – top 10 cm (TSOIL)
- Seasonal HWEC
Soil Respiration
9
MWD (b)
SWPD (a)
(ab)
PD
8
RSOIL (µmol m-2s-1)
7
6
5
4
3
2
1
May-June
July
August
Sept.
Oct.-Nov.
Conclusions
• SOC different - soil drainage classes & forest types
-
MWD > SWPD, PD
CF > BLD
belowground productivity (roots) & coarse fragments
wetland type matters (O vs. mineral)
• Similar SOC dynamics in aerobic near surface soil
- distribution of C in fractions similar drainage/forest
• Some imperfectly drained soils (SWPD, PD) could be
robust to extremes in moisture stress
• Complexity of forested landscapes
- soil drainage, forest types, parent material, wetland type, land use
history
Acknowledgements
Chris, Sara, Morgan, Sarah, Ben
Cheryl Spencer
Bruce Hoskins, Analytical Lab
Mike, Farrah, Andrea, Sarah, Erin
Sean
Hutchinson
Chris Dorion
Dr. Ivan Fernandez
Hope
Hopkins
Anja Whittington
Matt
Labonty
Nick
Berry
?