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

Action FP0903

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

THANK YOUfor considering

BELOWGROUND PROBLEMS & PERSPECTIVES