Soil Responses to Forest Canopy Disturbance
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Transcript of Soil Responses to Forest Canopy Disturbance
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Conor Flynn
The Ohio State University
Outline:
Definitions Hypotheses
Methods Results & Discussion
Conclusion Future directions
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Ryan MG, Law BE. Interpreting, measuring, and modeling soil respiration. Biogeochemistry. 2005.
Aspen/maple/oak
Even-aged
Disturbance/mortality
releases understory
Pine/maple/oak
Uneven-aged
Forest age (yrs)
0 10 20 30 40 50 60 70 80 90 100 110 120
Soil respiration response to canopy disturbance in a Northern Michigan Forest:
Soil respiration response to canopy disturbance in a Northern Michigan Forest:
The Forest Accelerated Succession ExperimenT (FASET)
Nave LE, Gough CM, Maurer KD, Bohrer G, Hardiman BS, Moine JL, Munoz AB, Nadelhoffer KJ, Sparks JP, Strahm BD, Vogel CS, Curtis PS. Disturbance and the resilience of coupled carbon and nitrogen cycling in a
north temperate forest. Journal of Geophysical Research. 2011
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Ryan MG, Law BE. Interpreting, measuring, and modeling soil respiration. Biogeochemistry. 2005.
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Ryan MG, Law BE. Interpreting, measuring, and modeling soil respiration. Biogeochemistry. 2005.
Aspen Oak
FASET (treatment)
GIRDLED
(released from competition)
Ameriflux (control)
no change
no change
Experiment Design: 4 Sites
Aspen Oak
FASET (treatment)
↓ Total Soil Respiration
↓ Rs Sensitivity to Temperature
↑ Total Soil Respiration
↑ Rs Sensitivity to Temperature
Ameriflux (control)
no change
no change
Hypotheses
Aspen Oak
FASET (treatment)
↓ Total Soil Respiration
↓ Rs Sensitivity to Temperature
↑ Total Soil Respiration
↑ Rs Sensitivity to Temperature
Ameriflux (control)
no change
no change
Hypotheses
Aspen Oak
FASET (treatment)
↓ Total Soil Respiration
↓ Rs Sensitivity to Temperature
↑ Total Soil Respiration
↑ Rs Sensitivity to Temperature
Ameriflux (control)
no change
no change
Hypotheses
Aspen Oak
FASET (treatment)
↓ Total Soil Respiration
↓ Rs Sensitivity to Temperature
↑ Total Soil Respiration
↑ Rs Sensitivity to Temperature
Ameriflux (control)
no change
no change
Hypotheses
Methods:
Automated Soil CO2 efflux Measurement
Methods:
Automated Soil CO2 efflux Measurement
FASET Aspen Site (FAS)
Methods:
Manual Soil CO2 efflux
Measurement
Results
Results: Growing Season Soil Respiration - Manual
0
1
2
3
4
5
6
7
8
9
10
153 180 194 208 230 244
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Day of Year
AF EFFLUX FASET EFFLUX
Results: Growing Season Soil Respiration - Autochambers
0
1
2
3
4
5
6
7
8
9
10
153 180 194 208 230 244
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Day of Year
AF EFFLUX FASET EFFLUX
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
129 149 169 189 209 229
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Dif
fere
nce
Day of Year
Difference
FAS-AAS
Results: Growing Season Soil Respiration - Autochambers
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
129 149 169 189 209 229
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Dif
fere
nce
Day of Year
Difference FAS-AAS
FOS-AOS
Results: Growing Season Soil Respiration - Autochambers
Results: Q10: Soil Respiration Temperature Sensitivity
y = 1.3944e0.0592x R² = 0.465
0
1
2
3
4
5
6
7
8
8 10 12 14 16 18 20 22
Soil
CO
2 E
fflu
x μ
mo
l m-2
s-1
15cm Soil Temperature C
FAS Efflux Q10= 1.81
Results: Q10: Soil Respiration Temperature Sensitivity
y = 1.3944e0.0592x R² = 0.465
0
2
4
6
8
8 10 12 14 16 18 20 22Soil
CO
2 E
fflu
x μ
mo
l m-2
s-1
15cm Soil Temperature C
FAS Efflux Q10= 1.81
Control Treatment
AAS AOS FAS FOS
Q10
(r2)
2.93a
(0.68)
2.84b
(0.59)
1.81c
(0.47)
2.39d
(0.75)
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
129 149 169 189 209 229
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Dif
fere
nce
Day of Year
Difference FAS-AAS
FOS-AOS
Results: Phenoperiod 1
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
129 149 169 189 209 229
Soil
CO
2 E
fflu
x μ
mo
l m
-2 s
-1
Dif
fere
nce
Day of Year
Difference FAS-AAS
FOS-AOS
Results: Phenoperiod 2
Results: Soil Respiration Sensitivity:
Phenoperiods
Control Treatment
AAS AOS FAS FOS
Q10
(r2)
2.93a
(0.68)
2.84b
(0.59)
1.81c
(0.47)
2.39d
(0.75)
Phenoperiod 1 Q10
(r2)
2.31a
(0.37)
3.86b
(0.74)
3.12c
(0.68)
2.97c
(0.74)
Phenoperiod 2 Q10
(r2)
2.37a
(0.35)
2.28a
(0.25)
1.27b
(0.04)
1.86a
(0.32)
Results: Soil Respiration Sensitivity:
Phenoperiods
Control Treatment
AAS AOS FAS FOS
Q10
(r2)
2.93a
(0.68)
2.84b
(0.59)
1.81c
(0.47)
2.39d
(0.75)
Phenoperiod 1 Q10
(r2)
2.31a
(0.37)
3.86b
(0.74)
3.12c
(0.68)
2.97c
(0.74)
Phenoperiod 2 Q10
(r2)
2.37a
(0.35)
2.28a
(0.25)
1.27b
(0.04)
1.86a
(0.32)
Aspen Oak
FASET (treatment)
↓ Total Respiration (↑ PP1 ; ↓ PP2)
↓ Total Rs Sensitivity to Temperature
(↑PP1; ↓PP2)
↔ Total Respiration
↓ Total Rs Sensitivity to Temperature
(↓PP1; ↓PP2)
Ameriflux (control)
no change
no change
Conclusions
Aspen Oak
FASET (treatment)
↓ Total Respiration (↑ PP1 ; ↓ PP2)
↓ Total Rs Sensitivity to Temperature
(↑PP1; ↓PP2)
↔ Total Respiration
↓ Total Rs Sensitivity to Temperature
(↓PP1; ↓PP2)
Ameriflux (control)
no change
no change
Conclusions
Aspen Oak
FASET (treatment)
↓ Total Respiration (↑ PP1 ; ↓ PP2)
↓ Total Rs Sensitivity to Temperature
(↑PP1; ↓PP2)
↔ Total Respiration
↓ Total Rs Sensitivity to Temperature
(↓PP1; ↓PP2)
Ameriflux (control)
no change
no change
Conclusions
Aspen Oak
FASET (treatment)
↓ Total Respiration (↑ PP1 ; ↓ PP2)
↓ Total Rs Sensitivity to Temperature
(↑PP1; ↓PP2)
↔ Total Respiration
↓ Total Rs Sensitivity to Temperature
(↓PP1; ↓PP2)
Ameriflux (control)
no change
no change
Conclusions
Aspen Oak
FASET (treatment)
↓ Total Respiration (↑ PP1 ; ↓ PP2)
↓ Total Rs Sensitivity to Temperature
(↑PP1; ↓PP2)
↔ Total Respiration
↓ Total Rs Sensitivity to Temperature
(↓PP1; ↓PP2)
Ameriflux (control)
no change
no change
Conclusions
Conclusions
Soil respiration reflects total belowground activity, and responds strongly to aboveground disturbance: less C in, less C out. Carbon cycle is resistant to natural disturbance as compared to anthropogenic. In undisturbed forests, root-derived respiration can contribute as much as 50% of total soil respiration. Heterotrophic respiration can be more sensitive to temperature than autotrophic, but depends on time of year – different drivers.
Problems and Solutions: Future Directions
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
-3
-2
-1
0
1
2
3
129 149 169 189 209 229
Vo
lum
etr
ic S
oil
Wa
ter
Co
nte
nt
%
FAS
Re
sid
ual
Un
exp
lain
ed
So
il R
esp
irat
ion
Doy of Year
residuals
SM_15cm2
R² = 0.1422
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
0 0.05 0.1 0.15 0.2
Volumetric Soil Water Content %
Problem: Soil Respiration Sensitivity to Change in Soil Moisture
Problem: Diurnal time-delay (Hysteresis)
3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
5.1
5.3
5.5
17.4 17.6 17.8 18 18.2 18.4 18.6
Soil
Res
pir
atio
n
Soil Temperature (15cm)
Time
Time
Midnight
Noon
6:00 PM
6:00 AM
6:00 PM
0
1
2
3
4
5
6
7
8
8 13 18
Effl
ux
15cm Soil Temperature
8
13
18
23
129 149 169 189 209 229
Soil
Tem
per
atu
re, C
DOY
15cm Soil Temperature AAS ST_15cm2
Continuous Wavelet Transform (CWT)
• Can be interpreted as time-localized power spectra (CF Fourier Transform) • Indicates time, period (i.e. wavelength), and power of signal
8
13
18
23
129 149 169 189 209 229
Soil
Tem
per
atu
re, C
DOY
15cm Soil Temperature AAS ST_15cm2
Continuous Wavelet Transform (CWT)
• Can be interpreted as time-localized power spectra (CF Fourier Transform) • Indicates time, period (i.e. wavelength), and power of signal
Cross-Wavelet Transform (CXT)
CXT indicates time-period domains of shared power between two signals
CXT also includes phase (lag) information with arrows
CXT AAS efflux and ST 15cm:
Continuous Wavelet Transform (CWT)
• Can be interpreted as time-localized power spectra (CF Fourier Transform) • Indicates time, period, and power of signal
0
0.05
0.1
0.15
0.2
129 149 169 189 209 229
Vo
lum
etri
c w
ater
co
nte
nt
%/%
DOY
15cm Soil Moisture
AAS SM_15cm
Cross-Wavelet Transform (CXT)
CXT indicates time-period domains of shared power between two signals
CXT also includes phase (lag) information with arrows
CXT AAS efflux and SM 15cm:
Wavelet Analysis:
CXT can identify: -Hysteresis time-lags
-Variable (episodic, pulsed) controls of soil respiration -CorrelationCausation
Acknowledgments
Dr. Peter Curtis Dr. Gil Bohrer Dr. Richard Dick Jen Nietz Dr. Chris Vogel, UMBS Dr. Valeriey Ivanov, UM Lingli He, UM Alexandra Permar, UNC …and many other collaborators!
Soil respiration is Important
Carbon Neutral?
Questions?
Results: Growing Season Soil Respiration - Autochambers
-1
0
1
2
3
4
129 139 149 159 169 189 199 209 219 230
Soil
Res
pir
atio
n D
iffe
ren
ce
DOY
Soil Respiration Difference AAS-FAS
significant
not significant
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
-3
-2
-1
0
1
2
3
169 179 189 199 209 219 229
residuals
SM_15cm2
Phenoperiod Residual Analysis
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
-3
-2
-1
0
1
2
3
129 139 149 159 169
y = 2.4628x - 0.2188 R² = 0.0112
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.05 0.1 0.15 0.2
y = 0.5907ln(x) + 2.0034 R² = 0.1899
-3
-2
-1
0
1
2
3
4
0 0.05 0.1 0.15
Growing Season Soil Respiration Driver: Soil Temperature
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
129 149 169 189 209 229
Soil
Wat
er P
ote
nti
al, K
pa
SWC
%
SM_15cm2
convert 15cm SM toMatric
Growing Season Soil Respiration Driver: Soil Temperature
0
5
10
15
20
25
0
1
2
3
4
5
6
7
8
129 149 169 189 209 229
Soil
CO
2 E
fflu
x μ
mo
l m-2
s-1
Day of Year
FAS efflux
ST_15cm2
Phenoperiods: Growing Season
-2
0
2
4
6
8
10
12
14
129 149 169 189 209 229
AF C Fluxes
Average of REgf
NEE
GPP
AAS efflux
AOS efflux
Substituting Rs for modeled Re in GPP calculations
-4
-2
0
2
4
6
8
10
12
14
16
129 149 169 189 209 229
NEEgf
REgf
GPP (NEE+Regf)
GPP (NEE+Rs)
Soil respiration response to canopy disturbance in a Northern Michigan Forest
Heterotrophic Soil Respiration: Biodiversity
Modified from Smith P, Fang C. Carbon cycle: A warm response by soils. Nature. 2010 March 24
What is the soil respiration response to succession?