carbon sequestration in coastal freshwater peatlands: a ... · carbon sequestration in coastal...
TRANSCRIPT
Carbon Sequestration in Coastal Freshwater
Peatlands: A Market Credit Tool for Restoration
Funded by
U.S. Fish and Wildlife Service, Region 4
&
The Nature Conservancy, NC Chapter
Curtis Richardson1, Neal Flanagan1, Hongjun Wang1, & Mengchi Ho1
&
Sara Ward2, and Tom Augspurger2
1Duke University Wetland Center, Nicholas School of the Environment
2U.S. Fish and Wildlife Service, Region 4
Outline
• Importance of restoring agricultural peatlands and drained wetlands
• Conceptual C credit accounting plan USFWS
• Experimental site description
• Questions
– Does hydrologic restoration increase GHG flux?
– Does restoration increase C and N Sequestration?
– What controls C sequestration ?
• Conclusions
(325 Tg C)
Drained and converted organic soils in agriculture that have potential for increased greenhouse gas losses
(unpublished map from NC RAMSAR working group)
PLNWR
Utrient
Wetland Restoration
Recommended expansion of restoration at Pocosin Lakes NWR
Why?
• Peatland restoration allows
substantive C and N
sequestration benefits
• Refuge habitat improvement
• Reduces nutrient runoff to estuaries
Photo: S.Ward, USFWS
(Peat Fire June –September 2008)
(How much C was lost?)
(NC Pocosin Fire 2008)
9.9 Tg C lost
16,814 ha Burned
Mickler and Welch 2012
Large Scale Hydrology-Carbon
Sequesration Experiment
Pocosins Lake National Wildlife
Refuge
in
Coastal NC
Reference
Restored
Restored
Restored
Drained
Drained (F1)
Experimental Design
Fire
Boundary
Gordonia lasianthus
Pinus serotina
Zenobia pulverulenta
Pinus taeda
Ilex glabra
Morella cerifera
Pteridium aquilinum0
500
1000
1500
2000
2500
Litt
er
acc
um
ula
tion
ra
te (
kg C
hr-1
yr-1
)
Reference
Restored
Drained
Litter Accumulation Rates in Pocosins by Species & Hydrology Treatments
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2
Ma
ss r
em
ain
ing
(%
ori
gin
al)
Time (yr)
SPDNLTPREFB7
C2
C14
Morella
50
55
60
65
70
75
80
85
90
95
100
0 0.2 0.4 0.6 0.8 1 1.2
Ma
ss r
em
ain
ing
(%
ori
gin
al)
Time (yr)
SPDNLTPREFB7
C2
C14
Ilex
Decomposition rates in drained, restored and reference pocosins
(Preliminary data from Tim Moore, McGill)
0.0
5.0
10.0
15.0
20.0
25.0
REF C2_REST C14_DRAIN
mg
/l
DIC
REF
C2_REST
C14_DRAIN
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
REF C2_REST C14_DRAIN
mg
/l
TOC
REF
C2_REST
C14_DRAIN
50% 80%
- -8x
Incomplete C Budget
100 Years left
Does Hydrologic Restoration Alone Control GHG Flux?
& Which GHG is the
Dominant Contributor?
Average By Treatment
-160
-140
-120
-100
-80
-60
-40
-20
0
20
01
/20
11
02
/20
11
04
/20
11
06
/20
11
07
/20
11
09
/20
11
11
/20
11
12
/20
11
RESTORED
DRAINED
REFERENCE
Sep.2011 Nov. 2011 Jan. 2012
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
CO
2 (m
g m
-2 h
-1)
Month
Drained sites
Reference sites
Restored sites
Sep.2011 Nov. 2011 Jan. 2012
0
100
200
300
400
500
600
700
800
CO
2 e
qu
iva
len
ts (
mg
m-2 h
-1)
Month
N2O
CH4
CO2
Drained sites
Sep.2011 Nov. 2011 Jan. 2012
0
100
200
300
400
500
600
700
CO
2 equ
ival
ents
(m
g m
-2 h
-1)
Month
N2O
CH4
CO2
Restored sites
Wet Dry Comparison of GHG
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0
0
200
400
600
800
1000
1200
1400
Drained sites
Reference sites
Restored sites
CO
2 (
mg
m-2 h
-1)
Water level (cm)
y = 3.9591x + 257.77
R2 = 0.6001
Dry Aug.
Wet Sep.
Average By Treatment
-160
-140
-120
-100
-80
-60
-40
-20
0
20
01
/20
11
02
/20
11
04
/20
11
06
/20
11
07
/20
11
09
/20
11
11
/20
11
12
/20
11
RESTORED
DRAINED
REFERENCE
Drought Effects ?
Questions
• How does this peat exist under such low summer water tables?
• What controls CO2 production in unsaturated peatlands? Phenolic cpds possible microbial block (Bridgham and Richardson, 2003)
• What are the responses of these peatlands to drought and can they resist drought effects? (Wang Ho and Richardson 2012)
Drought Low precipitation,
drainage for agriculture and forest
Aerobic decay
More CO2
Fenner and Freeman, 2011
Drought unlocks carbon historically restored in boreal peatland
Fenner and Freeman, 2011
Generally, such phenomenon occurs in
saturated peatlands,
However, unsaturated
peatlands?
High nitrogen in natural site Low C quality (C/N low) in drained site
1/28 2/12 2/27 3/14 3/29 4/13 4/28 5/13 5/28 6/12 6/27
1
2
3
4
5
6
CO
2 e
mis
sio
n (m
ol m
-2 s-1
)
Date
Drained
Natural
Restored
Figure 3. Temporal variation of CO2 emission during drought incubation of peat monoliths from drained, natural and restored Pocosin peatland sites.
No effects
(Wang , Ho and Richardson in Prep, Poster 336)
10
20
30
40
50
60
70
80
90
B
a
B
bB
c
B
a
A
a
A
a
B
b
A
bA
b
AB
c
A
c
So
il M
ois
ture
(v
%)
drained
Natural
restored
A
c
A
200
300
400
500
600
700
800
900
1000
B A
a
A
a
A
aAB
a
B
a
AB
a
B
a
B
abB
b
AB
a
B
b
B
b
So
lub
le p
oly
ph
en
ol
(g
C g
-1 d
ry s
oil)
1-Mar 31-Mar 1-May 1-Jul0
100
200
300
400
500
600
700C
A
a
A
a
A
a
A
aA
aA
a
A
a
A
a
B
a
A
aA
a
B
a
La
bile
po
lysa
cch
ari
de
(g
C g
-1 d
ry s
oil)
Date
1-Mar 31-Mar 1-May 1-Jul
1.0
1.5
2.0
2.5
3.0
3.5
4.0D
A
b
A
b
A
bA
b
A
a
A
a
A
a
A
a
A
a
Ph
en
ol o
xid
ise
act
ivity
(mm
ol d
iqc
g-1 m
in-1 )
Date
n/a
Figure 1. Temporal variations of soil moisture (A), soluble and polyphenol (B), labile polysaccharide (C) and phenol oxidase activity(D) during the drought incubation of peat monolith from natural, drained & restored Pocosin sites.
(Wang , Ho and Richardson in Prep, poster 336)
2.5 2.6 2.7 2.8 2.9 3.0 3.1
0.5
1.0
1.5
2.0
2.5
3.0
0 20 40 60 80 100
B
CO
2 e
mis
sion (m
ol m
-2 s
-1)
Log (Soluble polyphenol (g g-1 dry soil))
r2 = 0.694
p < 0.0001
A
Inorganic nitrogen (g N g-1 dry soil)
r2 = 0.4488
p < 0.001
Figure 4. Soluble polyphenol (A) and inorganic nitrogen (B, NH4++ NOx
-) vs. CO2
emission during the initial 60-day drought incubation of all peat monoliths
(Wang , Ho and Richardson in Prep, poster 336)
Phenolics-latch for CO2 production
Properties of Soil and Plants in the Pocosin Study Sites in Coastal NC
(Wang , Ho and Richardson in Prep, Poster 336)
Conclusion and application Build-up polyphenol inhibit CO2 production under drought
(weakens drought effects)
Moderate drought might increase C accumulation (similar with restored site results)
Altered species composition caused by drainage or by severe drought results in decreased polyphenol in soil & increased CO2 flux
Nitrogen deposition stimulates CO2 flux
Major Peatlands in the SE Coastal
Plain of the U.S.
Potential Peatland Restoration sites
Any Questions?