Presentation on theme: "SELF-ORGANIZATION OF SOIL SYSTEMS, ECOLOGICAL SIGNIFICANCE OF"— Presentation transcript:
1SELF-ORGANIZATION OF SOIL SYSTEMS, ECOLOGICAL SIGNIFICANCE OF TIME-SCALES ANDECOLOGICAL SIGNIFICANCE OFPEDOGENIC PROCESSESV. O. Targulian,Lomonosov Moscow State University;Institute of Geography, Russian Academy ofSciences,
2The main goal of this presentation is to generalize some existing notions and concepts of soil systems behavior in time, both under constant and evolving environment, to propose some considerations and working hypothesis concerning soil self-development, soil evolution, characteristic times of pedogenic processes and, at least, to assess the ecological significance of the WRB diagnostic horizons/properties
3Main Topics:Soil formation as a synergetic process of the soil system self-organization;Two main concepts of soil system behavior in time and their harmonization;Characteristic times of the WRB diagnostic horizons and specific pedogenic processes.Ecological significance of pedogenic processes and the main diagnostic soil horizons
4The main working hypothesis of the presentation is that soil formation could be perceived as a synergetic process of the soil system self-organization
5The soil formation (in its ideal model) - is a synergetic process of soil system self-organization in time, which tends to the attractor – mature soil body in steady state; In this process initial unsteady components and structures of the lithomatrix are transformed into new steady components and structures of the pedomatrix (soil body, soil cover). The pedomatrix after its formation becomes by the feedbacks a powerful regulator of the further functioning of the soil system.
12Endogenic cycles of rocks in lithosphere n*103 – 108 years Gas cyclesn*10-1 – 101 yearsWater cyclesn*10-1 – 102 yearsBiotic cyclesn*10-1 – 103 yearsExogenic cyclesof denudation &sedimentationn*102 – 104 yearsAnthropo-technogenic cyclesn*101 – 104 yearsSoil system residence time at land surfacen*102 – 106 yearsEndogenic cycles of rocks in lithospheren*103 – 108 yearsPlace of a soil on crossing of the main matter fluxes & cycles at land surface;Characteristic times of matter renewal in functioning soil system
13as bio-abiotic exogenic system BtMottled clay saproliteOrtho-bioticzonePara-bioticMeta-bioticSoil andweatheringmantleas in situformedhorizonatedbody –SITONand as afunctioningCRITICAL ZONEof a landscapeIdeal model of well-developed soil & weathering mantle in humid tropics by the age of years;The total thickness ofSITONas bio-abiotic exogenic systemSoil proper as an upper part ofweathering mantleMediumand lowerparts ofweatheringmantleRed-yellow saproliteCoarse saproliteGround waterParent rock
14100 D E P T H LIVING BIOTA HUMUS 50 % volume POROSITY GASES LIVINGBIOTA100HUMUS50%volumePOROSITYDEPTHGASESSOLID PHASE:MINERAL AND ORGANO-MINERALPARTICLESSOLUTIONS1м2 мINTERACTIVE COMPONENTS OF MULTIPHASEBIO-ABIOTIC SOIL SYSTEM
16Functioning (or “life”) of the multiphase soil system starts immediately at 0-time in the zone of multiple atmo-hydro-bio-litho- interactions within the parent material (lithomatrix of the soil system).
17= = Labile flux factors – “aggressors”: helio-atmo-hydro-bio; Driving forcesof pedogenesis=Exogenic soil-formingpotential of climate and biota - PCBInteractions of flux and site factors and their potentials in belowground stage of ecosystemgenicEmergence of soilfunctioning multiphasesystem in enclosingparent materialStatic immovable site factors– “acceptors”: parent rocks,relief; litho-topo-matrix of soil systemTransformational potential of parent rocks - TPPRRedistribution potential of relief –RPR=
18Processes (fluxes, cycles, exchange reactions) operating in the functioning soil system are not completely closed and reversible, therefore, they produce a range of residual products of functioning (RPF): gaseous, liquid, and solid Formation, accumulation, and differentiation of solid RPF in the soil system are the essence of soil formation as in situ development of the soil body (pedomatrix) from the parent material (lithomatrix); Soil formation (pedogenesis) is the “irreversible time-arrow” of the soil system functioning.
20Relation between multiphase processes of soil system functioning and specific pedogenic processes of formation solid phase pedogenic features
21Relationship between functioning of soil system Solid phase profiletimeorthoorthoorthoоrthоparaparaparaparaL I t o m a t r I xn*101-2yearsn*103-4yearsn*105-6yearsmetametaSapro-litemetametalabileprofiles ofbiota, gases,solutions,heatVertical zones of multiphase soil functioningRelationship between functioning of soil systemand formation of solid phase soil body
22We need to distinguish the multiphase soil system functioning and the solid phase soil body self-organization (self-development) in time:--multiphase soil system functioning on the land surface is potentially endless process, if not interrupted by denudation or burying,--solid phase soil body self-organization is potentially self-terminated process, as any synergetic process tending to attractor.
23present day horizonation of climate& biotapresent day horizonation ofsoil functioningsoildphaseprofilesoil functioning & developmentsolu-tionstime0-timebiotaheatgasesAorthoorthoorthoorthoEfunctioning withinsteady statesoil bodyfunctioningwith pedogenichorizonationfunc-tioningwithoutpedogenichorizona-tionBt,mparaparaparaparalitho-matrixsteady state soil bodysolid phase recordof long-termfunctioningsapro-litemetametametametatimesolid phasesoil bodyregulates soil functioningMODEL OF SOIL SELFDEVELOPMENT
25Soil systems behavior in time: self-development and evolution of sols
26Possible fates of soil systems in geological time scale: n*10 years burying and new pedogenesisPossible fates of soil systems in geological time scale: n* years4-6Continuation of “life” and evolution on the land surface0-timetechnogenic pollution – “poisoned” pedogenesisdenudationandnewpedo-genesis
27“meeting” & interaction of factors “agressors” and factors “acceptors” Factors of soil formation soil features Factors pedogenic processes soil features Factors processes of soil functioning pedogenic processes soil features“meeting” & interaction of factors “agressors” and factors “acceptors”fast cycling and renewal of labile components (gases, solutions, biota);formation & surviving of solid phase microproducts of soil functioningmultiphase bio-abiotic interactions in soil system; in situ labile horizonation of gases, liquids, biota and heat in parent rock;start of soil system functioningselection, accumulation & differentiation of solid phase microproducts within a soil system;formation of pedogenic soil macrofeatures, horizons & profiles;soil memoryVertical and lateral diversity of soil bodies and covers in space and timeEmerging and functioning of multiphase soil system in solid phase parent materialsFormation and evolution of pedogenic solid phase structure of soil system in space and time
28Soil A Soil B Soil C Steady-state Soil features Steady-state model of soil development(Dokuchaev, Jenny, Rode, Yaalon)FastprocessesSlowprocessestime, years101102103104105Progressive pedogenesisRegressive pedogenesisSoilfeaturesSoil ASoil BEvolutionary model of pedogenesis(Johnson, Keller, & Rockwell, 1984)Soil CT1T2TnT0
29Finity of soil self-development in constant environment: Under the constant environment, soil development is self-terminated process directed towards the steady state, because all specific pedogenic processes are either self-terminated due to depletion of initial resources, or come to dynamic equilibrium with the environment.Infinity of soil evolutionin the changing environment:Under the evolving environment without strong erosion and deep burying, soil evolution is an endless process, because specific pedogenic processes are changing following the driving changes of the environment.
30the steady state? processes Why soil system can approachthe steady state?Self-terminating pedogenic processesSoil featuresClay formationTexturedifferentiationCarbonateleachingPrimary silicatesdecompositionLeaching of bases from silicatestimeDynamically-equilibrium pedogenicprocessesSoil featuresHumus (formationvs decomposition)StructureBiogenic elementstime
31Possible changes of climate and biota SoilfeaturesIdeal model of soil andweathering mantleself-developmentcompared withpossibleenvironment changesduring this timesteady state of systemFast pedogenicprocessesSlowpedogenic processestime, yrs.Possible changes of climate and biotaduring 102 – 106 yearstemperature,precipit.time, years b.p.
32Soil-forming potential of climate & biota In arid - semihumid regions In humid regionsAnnualprecip., totropicalbiomasstemperateborealpolar90o45o0olatitudeIn arid - semihumid regionsAnnualprecip., tosteppesbiomasssemidesertssavannastundra-steppes(sub)tropicalpolar desertsdeserts90o45o0olatitude
33Two main models of soil evolution rainforcement of weathering andpedogenesisdeveloping & obliterating soil evolutionweakening of weathering & pedogenesisinheriting & superimposing soil evolution
34Dynamically equilibrium Individual pedogenic processes (IPP) in soil self-development and evolutionIPP groupsFiniteDynamically equilibriumIrreversibleReversibleObliterativeNon-obliterativeOrganic matter accumulation-+StructuringPedoturbationsSalinization - desalinizationCa(Mg)CO3 migrationWeatheringClay formationLeaching from solumVertical translocations ofclays, Fe, Al, Si
35of diagnostic horizons and specific pedogenic processes Characteristic timesof diagnostic horizons andspecific pedogenic processes
36Characteristic times (CT) of the main diagnostic horizons and properties (WRB) Long CTn*years:Ferralic, NiticPetro-(duric-plinthic-calcic-gypsic),Geric & Ferralic prop.diagnosticfeaturesShort CTn* years:Litter, Cryic,Folic, Ochric,Gleyic, Salic, Stagnic, Sulphuric, Takyric, Melanic,Plaggic-12Medium CTn* years:Albic, Andic, Argic, Calcic, Cambic, Duric, Ferric, Fulvic, Fragic, Gypsic, Histic, Mollic, Natric, Umbric, Vertic-11234567years
37Characteristic times of specific pedogenic processes (SPP) in soil self-development diagnosticfeaturesof SPPSlow SPPn* years:ferralitizationallitization,petro-cementation,deep sapro-litization6Fast SPPn* years:littering ,gleyzation,stagnation,salinization,brunification,cryo-, bio-turbations,structuring,compaction,etc…-12Medium-rate SPPn*103 years:mollic, umbric humification,cheluviation,andosolization,lessivage, partluvation,fersiallitization,Fe-,Si-cementation,carbonates migrationetc…-11234567years
38young ( alluvial, volcanic, dune) soils Characteristic times of specific pedogenic processes (SPP) related to soil absolute agediagnosticfeaturesof SPPSlow SPPn* years56Medium-rate SPPn* yearsFast SPPn* years-12-11234567yearsyoung ( alluvial, volcanic, dune) soilstundra & boreal soilstemperate soilstropical soils
39temperate seasonally freezing Absolute age of soils and the real duration of the pedogenesis (taking into account the warm and frozen conditions within the each year)T h e H o l o c e n e s o i l a g eX 1000 yearsarctictundraFrozen“age”Warm“age”boreal permafrosttemperate seasonally freezingsubtropics & tropics
40Interactions of the specific pedogenic processes Direct linkages(SPP chronochains, which are rather clear)Medium-rateSPPFast SPPSlow SPPFeedbacks(SPP time bombs, which are often latent)There are the main areas of synergetic interactionsin soil systems
41Ecological significance of WRB diagnostic horizons
42Diagnostic horizons (WRB) are perceived as attractors of the soil system development:
43Diagnostic horizons (WRB) are perceived as attractors of the soil system development: «Good» attractors are those states of the soil horizons, upon reaching which the horizons become more favorable for biota than in their previous states (in terms of biological productivity, biodiversity, and reproduction).«Bad» attractors are those states of the soil horizons, upon reaching which the horizons become less favorable for biota than in their previous states (in terms of biological productivity, biodiversity, and reproduction).
46MODAL DISTRIBUTION OF SOIL BIOTA AND HORIZONS-ATTRACTORS IN SOIL PROFILE ОORTHО-«GOOD»ATTRACTORSАЕРАRA-В«BAD»АТТRACTORSМЕТА-ВСSOLID PHASESOIL PROFILEBIOTIC ZONESIN SOIL
47Conclusions:1. Soil formation in the broad sense is a synergetic process of the soil system in situ self-organization during its functioning in time and space.2. Soil formation, sensu stricto, is the transformation of the solid-phase lithomatrix of the soil system into the pedomatrix (soil body, soil cover).3. Soil system functioning and soil formation are intimately linked but basically different processes: the former is infinite in time, if not interrupted by external factors; the latter, as any self-organization process, is finite in time and tends to reach its attractor (the steady state).
48.4. Soil formation consists of the set of specific pedogenic processes(SPP), which have different characteristic times and rates to reachtheir individual steady states, i.e. their attractors.5. SPP could be subdivided into three groups according to theircharacteristic times: fast SPP, medium-rate SPP and slow SPP,interacting in each soil body.6. Partial steady states could be reached by faster SPP on thebackground of slower proceeding SPP, so the directand feedback synergetic interactions among the different SPP areacting during pedogenesis; the complete steady state isimplemented, when the slowest SPP is realized in the soil system.7. Real duration of active pedogenesis in cold soils is shorter in 3-5 times than their absolute age, so no these soils have reached complete steady state but only partial steady states by fast and medium rate SPP..
498. All the diagnostic soil horizons (WRB) are perceived as more or less stable and «mature» attractors of soil self-development. They are separated into «good» and «bad» attractors with respect to biota.9. «Good» attractors include 13 out of 39 diagnostic horizons and properties (33%). They are mainly shaped by biotic fluxes and cycles, which are comparable to or exceed abiotic fluxes and cycles in their power and capacity. In this case, biota transforms and improves the environment rather than adapts to it.10. «Bad» attractors include 26 out of 39 diagnostic horizons and properties (67%). They are shaped by the mutual action of biotic and abiotic fluxes and cycles under the predominance of abiotic ones. In this case, biota adapts to the environment rather than transforms it.
51Soil formation - the myths and reality Gaia hypothesis (Lovelock, 1989, 1991): biota conducts all processes on the Earth surface, transforms and regulates abiotic environment rather than adapts to it.Soil formation is the transformation of parent material by biota with an obligatory consequent increase in its fertility and ecological suitability (Williams, 1930, 1945; Ponomareva, 1975; Van Breeman, 1990).Fertility is the main specific property of soil (widespread opinion).Is it true?
52Soil formation is a global, complex, bio-abiotic process inherent in biosperic planet; it comprises innumerable interactions of biotic and abiotic fluxes and cycles, which create various specific pedogenic processes (SPP);These SPP have different capacities, rates and opposing trends, therefore they build soil bodies as resultant systems with very complex and discrepant set of soil horizons and features;Global pedogenesis is not purposeful, ruled only by biota, harmonious process, on the contrary, it is very contradictory bio-abiotic process in time and space, which can cause positive as well as negative results for land biota;Such understanding of soil formation allows us to assess the role of soil systems in the biosphere more sensibly and to avoid an overestimated “biospheric euphoria”
53Soil fertility has his own specificity among these systems: Fertility is a distinctive but not absolutely specific feature of soil;Fertility is also the ingraine feature of all bio-abiotic Earth systems including atmosphere and hydrosphere, terrestrial and marine ecosystems and the biosphere as a whole;Soil fertility has his own specificity among these systems:it is “long-term stored” fertility in a form of stable solid phase soil composition and arrangement,it is “inertial” fertility long-term accumulated in situ within a soil system7