Biochemical characteristics of peat organic matter and distribution
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QuickTime™ et un décompresseur TIFF (non compressé) sont requis pour visio mical characteristics of peat organic matter and distrib mical characteristics of peat organic matter and distrib tate amoebae patterns in naturally regenerating cutover tate amoebae patterns in naturally regenerating cutover um um peatlands of the Jura Mountains peatlands of the Jura Mountains . Laggoun-Defarge 1 , E. Mitchell 2,3 , D. Gilbert 4 , B. Warner 5 . Comont 1 , J.-R. Disnar 1 & A. Buttler 3,4 1 Earth Sc. Inst., CNRS-Univ. Orleans, France Earth Sc. Inst., CNRS-Univ. Orleans, France 2 Univ. Alaska, Anchorage, USA Univ. Alaska, Anchorage, USA 3 EPFL & WSL-AR, Lausanne, Switzerland EPFL & WSL-AR, Lausanne, Switzerland 4 Univ. Franche-Comte, Besançon, France Univ. Franche-Comte, Besançon, France 5 Univ. Waterloo, Ontario, Canada Univ. Waterloo, Ontario, Canada
description
Biochemical characteristics of peat organic matter and distribution of testate amoebae patterns in naturally regenerating cutover Sphagnum peatlands of the Jura Mountains. F. Laggoun-Defarge 1 , E. Mitchell 2,3 , D. Gilbert 4 , B. Warner 5 , L. Comont 1 , J.-R. Disnar 1 & A. Buttler 3,4. - PowerPoint PPT Presentation
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Biochemical characteristics of peat organic matter and distribution Biochemical characteristics of peat organic matter and distribution of testate amoebae patterns in naturally regenerating cutover of testate amoebae patterns in naturally regenerating cutover SphagnumSphagnum peatlands of the Jura Mountains peatlands of the Jura Mountains
F. Laggoun-Defarge1, E. Mitchell2,3, D. Gilbert4, B. Warner5, L. Comont1, J.-R. Disnar1 & A. Buttler3,4
11Earth Sc. Inst., CNRS-Univ. Orleans, FranceEarth Sc. Inst., CNRS-Univ. Orleans, France22Univ. Alaska, Anchorage, USAUniv. Alaska, Anchorage, USA33EPFL & WSL-AR, Lausanne, SwitzerlandEPFL & WSL-AR, Lausanne, Switzerland 44Univ. Franche-Comte, Besançon, FranceUniv. Franche-Comte, Besançon, France55Univ. Waterloo, Ontario, CanadaUniv. Waterloo, Ontario, Canada
Which vegetation to promote ?Which related diversity ?
CUTOVER BOGSCUTOVER BOGS
CO2CH4
REGENERATED BOGSREGENERATED BOGS
CH4 CO2
Which microbial communities and processes ?Fate of organic matter ? Biomarkers ?
Starting conditions for potential restoration:Water table ?Chemical properties ?
Abandoned peatlands Abandoned peatlands Peatlands designated for restorationPeatlands designated for restoration
Restablish primary productionRestablish primary productionLong-term C-sequestrationLong-term C-sequestration?
RECIPE (EC FP5RTD) RECIPE (EC FP5RTD) “Reconciling commercial exploitation of peat “Reconciling commercial exploitation of peat with biodiversity in peatland ecosystems”with biodiversity in peatland ecosystems”
RECIPE: cutover Sphagnum-dominated peatlands that are being regenerating
studied sites: range of regeneration stages
France
Switzerland
N
La chaux d’Abel/CH
wet fenearly regeneration stage
dry boglater regeneration stage
non exploited area: reference
The sites: La Chaux d’Abel
0-3 cm amoebae
1 m profiles: 3 X 8 depths
OM analyses :-C, N-Micromorphology-Sugars-bacteria
SPECIFIC OBJECTIVES
determine biochemical characteristics of peat organic matter
determine biodiversity of microorganisms (testate amoebae)
Identification of bioindicators of environmental changes
Clues for the functioning of the system
C/N ratios and microscopic counting
(1/3) La Chaux d’Abel / poor fen (early regeneration stage)CA.1 Sphagnum & Polytrichum
Regenerating litter
“Old” catotelm peat
C/N ratios and microscopic counting (2/3)
CA.5 Sphagnum & Polytrichum
La Chaux d’Abel / bog (later regeneration stage)
Regenerating litter
“Old” catotelm peat
C/N ratios and microscopic counting
(3/3) La Chaux d’Abel (non exploited area)
Vascular plant remains
Higher degradation
Vascular plant remains
Higher degradation
Drainage phase ?Drainage phase ?
Drainage phase ?Drainage phase ?
Markers of organic sources(sugar analyses)
ERIOPHORUMERIOPHORUM
XyloseXyloseArabinoseArabinose
POLYTRICHUMPOLYTRICHUMMannose HMannose H
SPHAIGNESSPHAIGNES
RhamnoseRhamnoseGalactoseGalactose
S. rubellum
Rhm
Gal
%
ERIOPHORUM
Ara
Xyl
%
POLYTRICHUM Man H
%
S. fallax
Rhm
Gal
%
Living plants
sugar analyses
ERIOPHORUMERIOPHORUM
POLYTRICHUMPOLYTRICHUM
SPHAIGNESSPHAIGNES
XyloseXyloseArabinoseArabinose
Mannose HMannose HRhamnoseRhamnoseGalactoseGalactose
La Chaux d’Abel / regenerated bog
% Arabinose et Xylose
d
ep
th (
cm
)
% Mannose
Polytrichum- dominated peatRegenerating litter
vascular plant-dominated peat
higher degradation
Total sugar content in CA.5 [mg/g]
ERIOPHORUMERIOPHORUM
POLYTRICHUMPOLYTRICHUM
SPHAIGNESSPHAIGNES
XyloseXyloseArabinoseArabinose
Mannose HMannose HRhamnoseRhamnoseGalactoseGalactose
% Glucose % Xylose % Man, Ara, Fuc, Rib
sugar analyses d
ep
th (
cm
)La Chaux d’Abel / non-exploted area
Total sugar content in CA.6 [mg/g]
bacteria counting (La Chaux d’Abel)
Taille échantillon Taille échantillon de départ de départ
density ofdensity of bacteria/g bacteria/g fresh peatfresh peat
BIOMASSBIOMASSCarbonCarbon
BiovolumeBiovolume
DEP
TH
(cm
)
REGENERATED Zone
Abondance b/g.dry sampl.Biomass mgC.g
CA 5
NON EXPLOITED Zone
Abondance b/g.dry sampl.Biomass mgC.g
CA 6
DEP
TH
(cm
)
Drainage phasesDrainage phases
Regenerating litter
« Old » peat
Testate amoebae
A dominant group of protozoa in Sphagnum-dominated peatlands.
They are numerous & diverse. Like other microorganisms they have
a higher turnover rate than most other groups of organisms usually used as bioindicators.
Testate amoebaeNumerical analysesNumerical analyses
- Existing database from the Jura Mountains (Mitchell et al., 1999)used to derive transfer functions for pH and the depth of water table (DWT)
- These transfer functions used to infer pH and DWT from the regenerationsequence samples
- A species x samples matrix created with these 2 data (only common speciesto both data sets were kept)
- A conservative taxon. approach used & relative abondance of each speciesin each sample calculated
- Program WACALIB used to determine ecological optima of species and infer pH & DWT values of the samples
- Inferred pH vs inferred DWT for the regeneration sequence => How these 2 variables change along the sequence
CA-1-1
CA-1-2
CA-1-3
CA-2-1
CA-2-2
CA-2-3
CA-4-1
CA-4-2
CA-4-3
CA-5-1
CA-5-2CA-5-3
CA-6-1
CA-6-2
CA-6-3
10.00 3.99
16.24
4.26
22.48
4.53
28.72
4.80
34.95
5.07
Depth to the water table [cm]
pH CA-4
CA1&2
CA-5&6
CA-1
CA-5
CA-2
CA-6
CA-4
Hyalosphenia papilioNebela tinctaAssulina muscorumAmphitrema flavumEuglypha ciliataCorythion dubiumNebela tincta var. majorAssulina seminulumNebela militarisPhryganella acropodiaEuglypha compressaHeleopera sylvaticaHyalosphenia elegans
Community structure in the regeneration sequence
Conclusions
- A continuous trend from wet to drier / more acidic conditions thanks to testate amoebae communities (from Sphagnum mosses) Similar approach can be applied: establishment of a stratigraphy communities in peat cores to monitor changes through time
- OM composition of regenerating litters is similar to that of intact zone (C/N: 60-80)
- early regeneration: homogeneous (mainly Sphagnum remains)- late regeneration: heterogeneous (Sph. & Polyt. remains, AOM), better preservation of monosaccharides
- Specific indicators of organic sources identified from sugar analyses:- Reconstitution of different plant successions- higher degradation of OM associated with vascular plant settlement
