belowground complexity - cnrcost-fp0903.ipp.cnr.it/downloads/rome_conference/kraigher.pdf ·...
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Action FP0903Action FP0903
Climate Change and Forest Mitigation and Adaptation in a Polluted Environment
[MAFor]
BELOWGROUND COMPLEXITY
COST action FP 0803BELOWGROUND CARBON TURNOVER
IN EUROPEAN FORESTSHojka Kraigher & Primož Simončič
Slovenian Forestry Institute, Slovenia
Action FP0903
• Terrestrial plants allocate belowground 60 Pg C fixed annualy (ca 6 Pg C is combusted from fossil fuel annually into the air) (Giardina & al 2006)
• Belowground carbon allocation (BCA) is the largest sink for gross primary production & Rs 3rd largest C flux
• “A warm response by soil” (Smith & Fang N&V on Bond-Lamberty & Thompson, Nature 2010)
• Yet, BCA is the least understood C flux due to high complexity of the above and belowground interactions
• COST E38 ⇒ COST FP 0803 & 0903petagram (Pg) = 1015 grams
R.Finlay 2009
C fluxes in forest ecosystems
Action FP0903
COST FP 0803: Oct 2009 – Apr 20132nd meeting 01-04 September 2010
in Ljubljana, Slovenia
•Chair: Ivano Brunner, CH•WG1: Fine root turnover•WG2: Mycorrhizal mycelia turnover•WG3: SOM fractionation & Soil C stocks•WG4: ModellingWG discussions: preparation of common papersSpeed dating: inter-WG discussions & clarificationsExcursion: Karst ‘super site’
Action FP0903
BELOWGROUND COMPLEXITY
ABIOTIC & BIOTIC plant, animal, fungal &
microbialDIVERSITY &
INTERACTIONS
Action FP0903
A. Komarov:Soil is a horror for a modeller!
(Sergey Bartsev, Krasnoyarsk, 2009)
Ch. Anderson: O3 and Below-ground C Dynamics
• “The Good”- Our mechanistic understanding at the plant level
• “The Bad”- Our ability to predict the responsesin complex ecosystems
• “The Ugly”- Our non-understanding of soil ecosystem responses to O3
SOM
Photosynthesis
CCCCCCO2C
CCC CC
Carbon cycling in a forest (Ineson 2010)
C
C assimilation
above-groundlitter input
autotrophic respiration
below-groundlitter input
root & mycorrhizalrespiration
soil CO2 efflux
Soil organic matter (SOM) formed from above- and below-ground litter input
Plant responses to climatic change and impacts on soil C turnover are a significant source of uncertainty for current ecosystem models
Partitioning oftotal soil CO2efflux
Action FP0903
Climate and other human induced
influencesEnvironmental
changesHerbivores
Mycorrhizo-sphere
Soil properties
Soil food web
Soil organic matter
Ground vegetation
Coarse woody roots
Fine roots
Mycorrhiza
Hyphosphere
Carbon dynamics in soil:fluxes and biomass turnover
Rhizosphere fluxes
Mycorrhizo-sphere fluxes
Grebenc & Kraigher 2009, mod. after Giardina et al 2006
Belowground complexity
Action FP0903 Coarse root standing stock
Images obtained by ground penetrating radar (from www.casiroz.de)
Estimations based on limited data obtained by:•Digging up•Cleaning with air spade•Ground penetrating radar•Following roots in caves or after uprooting of trees
In average 10% BCA, depending on •tree species & age,•community & site,•nutrient & water,•temperature, ...
Photos by HK
Action FP0903
Fine root lifespan & turnover:Lukač and PritchardWhat is a fine root (FR): depends on its function ⇒ sp - dependent size (0,3 to 2 mm for woody roots)
How to define a dead root ⇒ non-turgescent or dissapeared
Does a fine root include mycorrhizal root tips ⇒ quantitatively yes, qualitatively diff. in spp diversity and function
Methodological concerns ⇒ data on FR lifespan differs for <1 year to >10 years
Are any generalizations possible on FR biomass & turnover ⇒ differences in species, geographical and altitudinal locations (Finer et al 2007)
Action FP0903
Soil coringingrowth coresroot inclusion netssequential coring
Minirhizotrons
Isotopic techniques“bomb 14C”stable isotope approaches
~ 1.8 yrs
<1.0 yrs to >10 yrs
3-32 yrs
Methods used to quantify FR turnover (Pritchard 2010)
Analiza preživetja
Dolgoživost (Št. dni)
0 100 200 300 400 500 600 700
Pre
žive
tje (%
)
0,0
0,2
0,4
0,6
0,8
1,012
Železnik 2010
Minirhizotrons: Survival analysis & censoring of dissapeared FR
Survival Analysis
Cas (št. dni)
0 200 400 600 800 1000
Sur
viva
l
0,0
0,2
0,4
0,6
0,8
1,0P64 (mean longevity =457 days)
N0 of roots = 350
Action FP0903
•75% terrestrial C in forests•>50% in forest soils•20%-30% in mycorrhiza•80% in extramatrical mycelium
Ectomycorrhizal fungi
Ca 80.000 species described, 1.500.000 estimated (Bridge & Spooner, 2001)About 6.000 species can form ectomycorrhiza
Functional diversity: fungi possess diverse exoenzymes for decomposition of organic polymers, & also for degradation of wood
Photos by HK
DNA based identification and diversity assessment
Material at SFI: roots & ectomycorrhiza, fungi, rhizosphere, soil, forest trees, seeds & seedlings etc.
Molecular analyses of single ECM at
species level
Population analyses and
identifications in mixed samples
ECM anatomy& morphology
PCR-RFLP
Identification based on RFLP database reference material
(ECM & fungi)
PCR and sequencing of informative regions
in genome
DGGE/TGGE
Community analyses from mixed
environmental samples
DNA bar coding*SSCP*
T-RFLP*
PCR-RFLP database (http://www.gozdis.si/)
Photos: H.Kraigher
Photo: T. Grebenc
Identification applying phylogenetic trees
. 2 mm .
Photos T.Grebenc & M. Bajc
Action FP0903
A
genotip 1 (Pireneji)
genotip 2 (Slovenija)
genotip 3 (Slovenija, Apenini)
genotip 4,5 (Balkan, Slovenija)
The importance & application of ECM in forests:
Post-glaciation co-migrations of truffles & oaks in Europe: projection to future CC scenarios!
Mycobioindication of stress & disturbance in forest soils by mapping of ECM
Grebenc et al 2010
Action FP0903
SOM fractionation (Cerli 2010)
solutio
n air
organ
ic
materia
lminerals
SOILSOM fractionation applied in models (Komarov 2010)
Action FP0903
• Climate and C,N,P interactions appear vital to understanding N fixation at the global scale: ecological and biophysical mechanisms
• Nutrient limitation of CO2 uptake is likely to play a major role in regulating Earth’s future climate
• Most of the models underestimate climate warming associated with elevated CO2
Carbon-nutrient Interactions and Climate Change: Towards an even warmer world? (Houlton 2010)
Action FP0903
Low complexity High complexity
Young plantsSimple interactions
Cause-effect linkagesMechanisticresponses
Adult treesIntact soil food web
Complex InteractionsSystem-level
effects
Controlled chambers Forest ecosystems
Modif. after Andersen 2010 and Kraigher et al 2008
Drawing by D.E.Hanke