Basisinteraktionen in Ökosystemen

Mechanistische GrundvorstellungenSymbole nach OdumZerlegung in StoffkreisläufeEinschränkung auf messbare/gemessene ParameterTheorie zu nachhaltiger Nutzung

Letzte Änderungen: GB 07.03.02 10:00

Ökologische Forschungsprojekte

•Thema/Gebiet•Fragestellungen: allgemein/speziell•Arbeitshypothesen formulieren•Untersuchungs-/Versuchsansatz/experimentelles Design•Vorversuch + Evaluierung•Hauptversuch 1•Auswertung

Evaluation der HypothesenNeue Befunde /Zusammenhänge

•Nachversuch/Hauptversuch2Nachbessern der Hauptexperimente

•Endauswertung/Synthesephase•Modellbildung, Diskussion (Hypothesenevaluation)•Definition des Forschungsbedarfs

VegetationSubstrates(Sugars, Amino Acids,Organic Acids)

Microbial Activity(Soil Enzymes)

Gas Exchange(N2O, CO2 , CH4 , C2H2)

Microbial Biodiversity(PLFA)

NH4+ NO3

-

N2

Mineralisation Nitrifikation

Den

itrifi

katio

nN

2-F

ixie

rung

AminoSäuren

Streu

Der Stickstoffkreislauf im Ökosystem

Auswaschung

TiereMiO

pH

DOM

POM

italic....

normal...

ureides urease activity ammonia

protease activity microbial biomass

leaching

mesofaunagrazing

grazing litter

mass transfer

activity

poolinfluence

MiOCO2

additional (RESP)

investigated system

inhibition

substrate enzymeN/C -

pH

enzyme activation / inhibitionenzyme induction / repressionabundance changediversificationadaptationslong term effects (succession)

mass flow

influence

stimulatingor inhibitingeffects:

basal (BR)original pool

supplement

Basisinteraktionen, Mesokosmenversuch, mechanistisch

XorgXdetr

Xmin

PflanzenMESOFAUNA

Bakt.Pilze

atm. Export

Auswaschung

Cyano-bacteria

atm. Import

Organismen-migration

SteuerungMaterial/Energie

E- AbflußEnergiequelle Regler Passiver Speicher

Konsument

Steuerkreis

Lastkreis

Xorg....organisch geb. N/CXmin....remineralisierter N/C

Nach H.T.Odum, 1971

POM....particulate org. matterDOM....dissolved org. matter

MESOFAUNA

Xmin

Xorg

Pflanzen

SteuerungMaterial/Energie

Migration

Auswaschung

atm. Exportatm. Import

Cyano-Bakt

Basisinteraktionen, nach Odum

N- Turnover im Boden

MESOFAUNA

Pflanzen

DOM

POM

MiO

NH4

NO3

N2 N2ONOxN2

GC/HPLC

CHN

Urease

N-Fixierung

Denitrifikation

Nitrifikation Nitratreduktase

Urease

Desaminierung A

Desaminierung B

Protease

h

NH4+

NO3-

Urease

N atmosph.

BR, SIR

PLANT

POM

DOM

Rhizodeposition,Litter Feedback

Mass TransferSteering influence

MESOFAUNA MiO

Free Amino Acids

Protease

N-Turnoverin Soils

MESOFAUNA

Pflanzen

DOM

POM

Cmin

MiO

C- Turnover im BodenCHN

XylanaseCellulase

GC/HPLC

Hmus

ß-GlucosidaseSaccharase

URAS

SIR

CHN

CO2 Methan

DOM

POM

Cmin

MiO

CO2

PLANT

h

Xylanase

Rhizodeposition,Litter

Feedback

Mass TransferSteering influence

Dehydrogenase

BR, SIR

Free Sugars and Amino Acids

MESOF

Cellulase

C-Turnoverin Soils

MESOFAUNA

Pflanzen

DOM

POM

MiO

P- Turnover im Boden

Pmin

Phosphatase

Fumigation

Ionentausch

MESOFAUNA

Pflanzen

DOM

POM

MiO

Smin

S- Turnover im Boden DMS

Ionentausch

Arylsulfatase

H2S

Rhizodeposition Strategies of Plant Species

high biomass production

- keeping a reserve for remineralisation by slow decomposers (K-strategy)

high exudation of low molecular weight organic substances

- quick substrates for fast remineralizing microorganisms (R- strategy)

Combinations (extremes) and their impact on ecosystems

high biomass and high exudation high turnover, steady state or shift?

high biomass and low exudation steady state, slow shift of biodiversity

low biomass and high exudation quick depletion of nutrients, degradation?

low biomass and low exudation steady state, slow turnover rates

hv

DOMorg. S

Fauna

Urease Aktivitätges.N

CO2

BakterienCO3

- -

Mg ++

MgCO3

Pilze

POMKn.Bak.

N2

TRIFOLIUM= Massentranfer= Steuergröße

hv

DOM

Fauna

Urease Aktivitätges.

N

CO2

CO3--Mg ++

MgCO3

Bakterien

Pilze

POM

= Massentranfer= Steuergröße

LOLIUM

basins of attraction

system elasticity

system stability

presentecosystem

future ecosystem

TemperatureFertilizer

Rhizodeposition

ecosystem succession due toland use ?

worst case:degradation

Stability of Soil Systems

system resilience

soil property (Soil aggregate stability)

ener

gy n

eede

d to

cha

nge

soil

prop

ertie

s

Asparagine induced Respiration (URAS)

0

20

40

60

80

100

120

0 90 180 270 360 450 540 630 720 810 900 990

Time (min)

mg

CO

2 / k

g FG

*h

Maniok

Sugar Cane

Maniok and Sugar Cane (BIOLOG-Test using Asparagine)

0

2000

4000

6000

8000

10000

0 840 1200 1440 2400 2670 3000 4320Time (min)

µg T

PF

/ mL

Sugar Cane

Maniok

Substrate activation, induction, resource limitation

CO2 Sink: Free Sugars in Plant and Soil

Bulk soil

Rhizosphere

Soil Partikels(Carbonates)

glucose and other free sugars in 1 kg soil: an average 20 to 200 mg

glucose and other free sugars in plants:an average of 2 -10 mg g DM -1

standing crop of grasses on 1 kg soil:an average of 10 -20 g DM

free sugars in the standing crop on 1 kg soil:an average of 20 -200 mg

transfer rates ?

Soil Respiration

exportleachingmigration

Root Biomass