shifting allocation & nutrient pools affect c stocks
TRANSCRIPT
![Page 1: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/1.jpg)
Shifting allocation & nutrient pools affect C stocksShifting allocation & nutrient pools affect C stocks
![Page 2: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/2.jpg)
Arctic Biosphere-Atmosphere Coupling across multiple Scales ABACUS
Plant &Soil processes Chamber Fluxes
Eddy fluxesAirborne fluxesAnd remote sensing
Earthobservation
Isotopelabelling
![Page 3: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/3.jpg)
The challengeThe challenge
Vegetation
Soils
Climate
priming
succession
Albedo, ETPhenology
CO2 effluxes
Microbialprocesses
![Page 4: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/4.jpg)
GPP Croot
Cwood
Cfoliage
Clitter
CSOM/CWD
Ra
Af
Ar
Aw
Lf
Lr
Lw
Rh
D
Photosynthesis &plant respiration
Phenology &allocation
Senescence & disturbance
Microbial &soil processes
Climate drivers
Non linear functionsof temperatureSimple linear functionsFeedback from Cf
![Page 5: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/5.jpg)
Two eddy flux sitesTwo eddy flux sites
Abisko birch woodland
Abisko tundra
![Page 6: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/6.jpg)
Carbon exchange in tundra heathCarbon exchange in tundra heath
Observed (EC) Modelled (SPA)mol m-2 s-1
Time of day Time of day
GPP = 594 gC m-2
Time of day
Tim
e o
f ye
ar
Net ecosystem exchange (measured) [ mol m-2 s-1]
0 400 800 1200 1600 2000
2007.3
2007.4
2007.5
2007.6
2007.7
2007.8
2007.9
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
Time of day
Tim
e o
f ye
ar
Net ecosystem exchange (modelled) mol m-2 s-1
400 800 1200 1600 2000 2400
2007.3
2007.4
2007.5
2007.6
2007.7
2007.8
2007.9
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
Data from Evans and Harding
![Page 7: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/7.jpg)
Carbon exchange in birch woodlandCarbon exchange in birch woodland
Time of day
Tim
e o
f ye
ar
Net ecosystem exchange (measured) mol m-2 s-1
0 400 800 1200 1600 2000
2007.3
2007.4
2007.5
2007.6
2007.7
2007.8
2007.9
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
Time of day
Tim
e o
f ye
ar
Net ecosystem exchange (modelled) mol m-2 s-1
400 800 1200 1600 2000 2400
2007.3
2007.4
2007.5
2007.6
2007.7
2007.8
2007.9
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
Observed (EC) Modelled (SPA)mol m-2 s-1
Time of day Time of day
GPP = 1080 gC m-2
Data from Evans and Harding
![Page 8: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/8.jpg)
Leaf growthand senescence
Fine rootdynamics
Data from Poyatos and Sloan
0
200
400
600
800
1000
1200
1400
150 170 190 210 230 250 270 290
Time (DOY 2007)
Mea
n l
eaf
area
(m
m2 )
50
60
70
80
90
100
110
Sm
iula
ted
lea
f m
ass
(g m
-2)
Constraining models with biometric dataConstraining models with biometric data
![Page 9: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/9.jpg)
Emergent ecosystem propertiesEmergent ecosystem properties
![Page 10: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/10.jpg)
Tundra heath
Mountain birch
Problems modelling soil organic matter dynamics!Problems modelling soil organic matter dynamics!
![Page 11: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/11.jpg)
![Page 12: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/12.jpg)
Sofie Sjögersten (‘DART’ Project)Universities of Uppsala & Nottingham
Iain Hartley (‘ABACUS’ Project)University of Stirling
Audrey Wayolle, SAGES
![Page 13: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/13.jpg)
Dovrefjell Abisko Joatka
Mountain birch forest 6.3 1.3 2.0
Tundra heath 10.1 3.9 2.4
Carbon storage (kg mCarbon storage (kg m-2-2) in the soil ) in the soil organic horizon in forest and tundra organic horizon in forest and tundra sitessites
Note: CPMAS 13C NMR analysis suggests tundra SOM also more labile
Sjögersten S & Wookey PA (2009) Ambio 38, 2-10
![Page 14: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/14.jpg)
0.5 km
Data from Wayolle, Wookey, Williams
0 10 20 30 40 50 60 70 80
Carbon content (%)
![Page 15: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/15.jpg)
Physico-chemicalEnvironment (P)
Decomposerorganisms (O)
Litterquality (Q)
After Swift, Heal & Anderson (1979)
+ Rhizodeposition
![Page 16: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/16.jpg)
Soil respiration and litter decomposition: Dovrefjell, Soil respiration and litter decomposition: Dovrefjell, Abisko and Joatka summarizedAbisko and Joatka summarized
Sjögersten S & Wookey PA (2009) Ambio 38, 2-10
![Page 17: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/17.jpg)
• Use of ‘bomb’ 14C peak (late 1950s to early 60s) in soils to investigate soil organic matter turnover (Iain Hartley with Mark Garnett, NERC RCF)
• IPY ABACUS ProjectNERC Radiocarbon Facility (Environment), East Kilbride
![Page 18: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/18.jpg)
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000 2020
Year AD
Rad
ioca
rbo
n c
on
ten
t (%
mo
der
n)
Data sources:
Reimer, P. J., et al. 2004 IntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr BP. Radiocarbon 46, 1029-1058.
Q Hua and M Barbetti, "Review of Tropospheric Bomb 14C Data for Carbon Cycle Modeling and Age Calibration Purposes", (2004) Radiocarbon 46: 1273-1298.
![Page 19: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/19.jpg)
Depth (cm)
0 1 2 3 4 5 6 7
14C
(%
mo
der
n)
90
95
100
105
110
115
120
125
130
Current atmosphere
Pre-bomb
1020 y BP
184 y BP
Site Depth 14C (% Modern)
Birch Forest 0-1 cm 135.321-2 cm 111.87Mineral 88.09
Heath
![Page 20: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/20.jpg)
ImplicationsImplications
• Calculations:– Pool size and MRT– Contribution of different layers to CO2 flux
• Much bomb C, little old C• Contribution of pre-bomb carbon to CO2 flux
should be very small• Not surprising in freely-drained soils
![Page 21: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/21.jpg)
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000 2020
Year AD
Rad
ioca
rbo
n c
on
ten
t (%
mo
der
n)
Data sources:
Reimer, P. J., et al. 2004 IntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr BP. Radiocarbon 46, 1029-1058.
Q Hua and M Barbetti, "Review of Tropospheric Bomb 14C Data for Carbon Cycle Modeling and Age Calibration Purposes", (2004) Radiocarbon 46: 1273-1298.
Older CO2 more14C enriched
![Page 22: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/22.jpg)
Respiration rates and Respiration rates and 1414COCO22 sampling sampling
• Two plot types:– Clipped and trenched = soil respiration only– Control = vegetation and soil respiration
• Measured respiration rates• Collected CO2 for 14C analysis
– Late May / early June– Mid July– Early September
![Page 23: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/23.jpg)
Respiration ratesRespiration rates
• Respiration peaked mid-season
• Plant contribution highest early and mid-season
Date
1/6/07 1/7/07 1/8/07 1/9/07
Res
pira
tion
rate
(g
CO
2 m
-2 h
-1)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2 controlCT
0.0
0.2
0.4
0.6
0.8
1.0
Date
1/6/07 1/7/07 1/8/07 1/9/07 P
ropo
rtio
nal c
ontr
ibut
ion
0.0
0.2
0.4
0.6
0.8
1.0
VegSoil
Tundra heath Tundra heath
Birch forest Birch forest
![Page 24: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/24.jpg)
• Early indications that mountain birch might be involved in ‘priming’ the decomposition of older SOM: labile litter or rhizodeposition?
14C
(%
Mo
der
n)
100
102
104
106
108
110
112 SoilUnderstorey
May July September100
102
104
106
108
110
112 SoilEco
(a) BIRCH
(b) HEATH
![Page 25: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/25.jpg)
14 14 C work - conclusions and implicationsC work - conclusions and implications
• Carbon turning over is mainly 5-10 years old• Mid-season positive “priming” of 14C-enriched
soil organic matter in birch forest• Partially explains the thin organic horizon in
birch forest• Implications for change in tree-line
(importance of plant species distributions)
![Page 26: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/26.jpg)
• Similar results becoming available from Kevo in Finnish Lapland
![Page 27: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/27.jpg)
But COBut CO2 2 is not the only GHG of interest!is not the only GHG of interest!
Environmental controlson CH4 fluxes arecomplicated!!
Environmental controlson CH4 fluxes arecomplicated!!
![Page 28: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/28.jpg)
ConclusionsConclusions• Productivity, biomass and soil C stocks are highly
variable over a range of spatial scales• Some basic ecosystem emergent properties are
strongly related to GPP• We still struggle to understand and model below-
ground processes• Vegetation change will engender significant
changes in SOM• We can’t assume that increased NPP will also be
associated with increased C sequestration in soils
![Page 29: Shifting allocation & nutrient pools affect C stocks](https://reader035.vdocuments.mx/reader035/viewer/2022062519/56649cb05503460f94974bd5/html5/thumbnails/29.jpg)
Acknowledgements:R. Baxter, M. Disney, J. Evans, B. Fletcher, M. Garnett,J. Gornall, R. Harding, I. Hartley, D. Hopkins, B. Huntley, T. Hill, P. Ineson, J. Moncrieff, G. Phoenix, V. Sloan, R. Poyatos, A. Prieto-Blanco, M. Sommerkorn, J. Subke, P. Stoy, L. Street, T. Wade, A. Wayolle, M. Williams,C. Wilson, and all the ABACUS team