安师大环境土壤学讲义07土壤形成和发育.docx

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1、UNITE2SOI1ENVIRONMENTA1PROCESSES第二篇土壤环境过程07.Soi1FormationandDeve1opment07土壤形成和发育目的要求掌握土壤形成影响因素及其在土壤中的作用，土壤形成过程的实质与主要成土过程。了解不同土壤的发育过程。7.1 Soi1-formingfactorsanditsfunctions土壤形成因素及其在土壤发生中的作用7.1.1 Soi1-formingfactors土壤形成因素Theoperationofpedogenicprocessesiscontro11edbyanumberofenvironmenta1factorsoperat

2、ingthroughthemediumoftimeandthatthesedeterminethetypeofsoi1producedinanyparticu1ar1ocation.土壤形成因素又称成土因素，是影响土壤形成和发育的基本因素，它是一种物质、力、条件或关系或它们的组合，其已经对土壤形成发生影响或将影响土壤的形成。7.1.1.1 成土因素学说：In1aternineteenth-centuryRussia,Dokuchaevorigina11yidentifiedtheprincipa1factorsasc1imate,biota,parentmateria1,re1iefand1a

3、ndscapeage.Theinf1uenceofenvironmentfactorsonsoi1formationwasconsideredinamoresystematicmannerfo11owingtheworkofJenny(1941).Soi1=f(c1,o,r,p,t,(h)C1orPt函数式五大自然成土因素：母质(parentmateria1)、生物(organisms)气候(CIimate)、地形(re1ief)、时间(time)。成土因素：五大自然成土因素、人为因素(humanactive)7.1.1.2 成土因素学说的基本原理：(1) 土壤是成土因素综合作用的结果Theo

4、perationofpedogenicprocessesiscontro11edbyanumberofenvironmenta1factorsoperatingthroughthemediumoftimeandthatthesedeterminethetypeofsoi1producedinanyparticu1ar1ocation.(2)成土因素具有同等重要性和不可替代性Thesoi1-formingfactorsoperateincombination.Itisnotpossib1etoranktheminorderofimportance-theyarea11equa11yimporta

5、nt,a1thoughwithinanyoneenvironmentcertainfactorsmayhaveamoredominantinf1uenceonsoi1formationthanothers.(3)成土因素的时空分异导致土壤演化持续进行7.11.3地带性土壤(Zona1soi1s)：Attheregiona1andg1oba1sca1e,c1imateandbiotawi11haveadominantinf1uenceonsoi1formation,andsoi1typescanbere1atedingenera1termstobioc1imaticzones.Theremain

6、ingfactorswi11thenaccountforvariationsinsoi1formationwithinaparticu1arbioc1imaticzone.Zona1soi1s:soi1variedwith1atitudeaccordingtoc1imaticandvegetationconditions.Intrazona1soi1s:soi1sweremorec1ose1yassociatedwithparentmateria1ordrainageconditions.Azona1soi1s:soi1swerepoor1ydeve1oped,duomain1yto1acko

7、ftime.7.1.2 Parentmateria1母质对土壤发生的作用土壤形成的基本过程：SurfacerockWeatheringcrust(风化壳)-*Parentmateria1(母质)Soi1WeatheringpedogenicprocessesParentmateria1ismainminera1sourcesofsoi1formation,anditsnatureisfundamenta1tomanysoi1characteristics.Themajorinf1uenceofparentmateria1onsoi1formationisseenintermsofminera1

8、transformation,whichisdeterminedbytheresistanceandreactionoftheminera1toweatheringprocesses.Parentmateria1a1soinf1uencetransfersand1ossesintermsofthemateria1avai1ab1eforparticipationinweatheringprocesses,andtheeaseofdrainageandremova1ofthesemateria1s.7.1.2.1 Definitionof,parentmateria1母质的概念母质是风化壳(We

9、atheringCrUSt)的表层，是指原生基岩(Origina1bedrock)经过风化、搬运、堆积等过程于地表形成的一层疏松、最年轻的地质矿物质层，它是形成土壤的物质基础，是土壤的前身。风化壳是地壳表层的岩石经过风化后形成的疏松堆积物。母质既不同于岩石：有初步肥力，颗粒分散，疏松多孔，有一定吸附、透水和蓄水性能。也不同于土壤：七缺乏养分，几乎不含C、N,通气和蓄水不能同时解决。7.1.2.2 Typesofparentmateria1母质的类型残积母质(residua1parentmateria1)：指岩石风化后，基本上未经动力搬运而残留在原地的风化物；运积母质(Ca1TiedParent

10、materia1)：指母质经外力，如水、风、冰川和地心引力等作用而迁移到其它地区的物质。又可以根据运移动力(水、风、冰川、重力等)进行细分，如冲积母质、湖积母质、冰积母质等。7.1.2.3 Functionsofparentmateria1insoi1formation母质的作用Themajorinf1uenceofparentmateria1onsoi1formationisexpressedprincipa11yintermsofweathering,asthisdeterminestheamountofminera1materia1avai1ab1etoasoi1profi1eanda1

11、sothesubsequentweatheringcharacteristicsofthesoi1itse1f.ThenatureandextentofweatheringWinbedeterminedbytheresistanceoftheminera1swhichmakeuptheparentmateria1anda1sobyvariousphysica1characteristicsoftheparentmateria1itse1f.Thenatureofweatheringasdeterminedbyparentmateria1isfundamenta1tomanysoi1charac

12、teristics.(1)影响成土过程的速度、性质和方向(2)影响土壤理化性状(如养分等)岩浆岩(magmaticrock)：花岗岩形成的土壤富钾而缺磷；玄武岩形成的土壤缺钾而富磷；沉积岩(SedimentaryrOCk)：砂岩形成的土壤盐基养分较贫乏；页岩形成的土壤盐基养分较丰富。(3)影响土壤矿物组成和性质(4)影响土壤发育和形态特征(morpho1ogica1characteristic)总之，成土过程进行得愈久，母质与土壤的性质差别就愈大。但母质的某些性质却仍会顽强地保留在土壤中。例如分布在我国华南的砖红壤是我国境内风化强度最深、成土时间最长的一类土壤，但母质对砖红壤的性质仍有深刻的影

13、响7.1.3 CIimate气候与土壤发生的关系C1imateisofparticu1arimportanceintermsofdeterminingthetemperature,andthereforerate,atwhichpedogenicprocessesoperate,anda1sotheavai1abi1ityofwater,whichisfundamenta1tomanyoftheseprocesses.气候因素决定土壤的水热状况，从而影响母质风化、植物生长、微生物活动和有机质的合成与分解。C1imaticinf1uenceonsoi1surfaceadditionsoccurv

14、iaaeo1ianandwatertransportandmassmovement.C1imatea1soinf1uencesoi1surfaceorganicadditionsindirect1yduotoitscontro1onvegetationtypesandtheirgrowthrate.C1imateinf1uencesthetransformationoforganiccomponentsbyitseffectonratesoforganicmatterdecay,maximumratesofdecayusua11ytakep1aceinthetemperaturerange25

15、-35oC(Ross,1989).Therateofminera1transformationviacrysta11atticebreakdownincreaseswithtemperature;ingenera1therateofchemica1reactionsdoub1esforevery10riseintemperature(Curtis,1976).Soi1materia1transferandminera1weatheringandtrans1ocationarehigh1ydependentontemperatureandmoisture.Thesewi11direct1yinf

16、1uencetheprocessesinvo1vingwatermovementandmechanica1transferanda1sohaveanindirectinf1uenceviatheircontro1onthetypeandquantityofvegetationandontheorganismsassociatedwithbioturbation.Soi11ossesarecontro11edviac1imateinf1uencesonwaterandwindtransport,anda1soindirect1ybyinf1uencesonbiota.7.1.3.1 气候对土壤形成的影响(1)湿度(humidity)：影响土壤中物质的迁移；影响土壤中物质的分解、合成和转化。(2)温度(temperature