实验生态学-第四章 生态工程及全生态系统原理及方法

第4章：生态工程及全生态系统原理与方法（2学时）\n1、基本概念一、核心原理1、整体性原理（整体论和还原论的争论）：生态工程是以整体观为指导，在系统水平上来研究，整体调控为处理手段。2、协调和平衡原理：由于生态系统长期演化与发展的结果，在自然界中任一稳态的生态系统，在一定时期内均具有相对稳定而协调的内部结构和功能。生态系统在一定时期内，各组分通过相生相克、转化、补偿、反馈等相互作用，结构与功能达到协调，而处于相对稳定态，这种稳定态就是一种平衡。包括结构平衡、功能平衡、收支平衡。\n3、自生原理（self-resiliency）：包括自我组织（self-organization）、自我优化（self-optimum）、自我调节（self-regulation）、自我再生（self-regerenation）、自我繁殖（self-reproduction）和自我设计（self-design）等一系列机制。自组织或自我设计：是系统不藉外力自己形成具有充分组织性的有序结构，也即生态系统通过反馈作用，依照最小耗能原理，建立内部结构和生态过程，使之发展和进化的行为，这一理论即为自组织理论。\n自我优化：是具有自组织能力的生态系统，在发育过程中，向能耗最少、功率最大、资源分配和反馈作用分配最佳的方向进化的过程。自我维持：是指生态系统是直接或间接地依赖太阳能的系统，因而是一个自我维持的系统。自我调节：是属于自组织的稳态机制，其目的在于完善生态系统整体的结构与功能。\n4、循环再生原理：物质循环和再生原理：多层次分级利用原理：物质再生循环和分层多级利用，不仅意味着在系统中通过物质、能量的迁移转化，去除一些内源和外源的污染物；还要利用这特有的工艺路线，达到尽量高产、低耗、高效地生产优质产品；还要做到变废为宝，保证转化后的一些物质输出的可能性，同步收到生态、经济和社会三方面效益。再生循环与分层多级利用物质是系统内耗最省、物质利用最充分、工序组合最佳最优工艺设计的基础。\n二、生物学原理物种共生原理：生态位原理：食物链原理：物种多样性原理：物种耐性原理：景观生态原理：耗散结构原理：限制因子原理：环境因子的综合性原理：\n三、工程学原理结构的有序性原理：系统的整体性原理：功能的综合性原理：\nWhole-ecosystemstudiesareinsituecologicalstudiesandexperimentsofsuchaspatialandtemporalscaleastoincludemostifnotallprocessesoftheecosystem.Principlesofself-organizationandself-designarekeytowhole-ecologicalfunctionandoftendonotoccurasvibrantlyorconclusivelyatsmallerscaleexperiments.Ecologicalfeedbackcausedbyorganisms(e.g.,beavers,plantsthatmanagehydrology,ecosystemengineers,top-downcontrol),pulsescausedbyeventssuchasfireandfloods,andemergentecosystempropertiescausedbyhumanwastes,recycling,andhydrologicmodificationaredifficultifnotimpossibletobeproperlystudiedinsmall-scaleexperiments.\nLarge-scalewhole-ecosystemstudieswerepioneeredinthe1960sand1970sbyH.T.OdumandcolleagueswithlargedropnetsinTexascoastalbays,rainforestsenclosuresinPuertoRico,createdcoastalpondsinNorthCarolina,andsewageapplicationtocypressswampsinFlorida.ThestudyinFloridainvestigatedeffectsofwastewateradditionstowetlandfunctionincypressdomesbutunexpectedfireintheexperimentalarealedtoadaptiveresearchandthestudyoffireinfieldresearchandmodels.Morerecentlywehavebeenengagedinwhole-ecosystemexperiments,partiallyinspiredbytheworkofOdum,atcreatedwetlandsinnortheasternIllinoistoinvestigateeffectsofwaterturnoveronecosystemfunctionandinOhiotoprovideinsightonthelong-rangelarge-scaleeffectsofhydrologyandmacrophyteplantingonecosystemfunction.\nWehavealsocarriedoutmajorecosystem-scalestudiesincoastalLouisiana,investigatingthevalueoftheseecologicalsystemsintreatingwastewaterandrestoringlostlandscapeincoastalLouisiana.ThesestudiesintheMidwestandMississippideltaformthebasisofdeterminingdesignstandardsoncreatingandrestoringwetlandsintheMississippiRiverBasintoreducetheGulfofMexicohypoxiaandregainmanylostecosystemfunctionsoveralargepartofNorthAmerica.\nObtainingdataonbiomassrepresentativeofthelargesystemsofnaturesuchasforestsandseasisaverydifficulttaskthathasoccupiedecologicalresearchfor50yearswiththousandsofmethodsandvaryingresults.Whensmallspotsarestudiedorsmallsamplestaken,thedataarenotrepresentativebecauseofthelargestatisticalvariationthatischaracteristicofmostecosystems.Effortstosamplelargesectionsofsystemsarelaboriousandexpensive.From:H.T.Odum(1971,Environment,Power,andSociety)\n1.IntroductionEcologyisstudiedatmanydifferentscales—microcosms,mesocosms,wholeecosystems,andland-scapes.Whole-ecosystemstudiesaredefinedhereasinsituecologicalstudiesofsuchaspatialandtemporalscaleastoincludemostifnotallprocessesoftheecosystem.Theimportanceofwhole-ecosystemstudiesismorethanjustlargesize.\nAwhole-ecosystemstudypurposefullydoesnotsimplifyanecosystemtoderivecauseandeffectmoreeasily;itattemptstoincludemanymorepathwaysandfeedbacksinthesystemthandosimplersystems.\nTheoriesnowcalledself-organization,self-design,ecosystemengineering,andpracticessuchasecologicalengineering,adaptiveresearchandecosystemmodelingemergedfromwhole-ecosystemstudies;theimpactofwhole-ecosystemresearchontheteachingofecologyhasbeenenormous.\nTheprinciplesofself-organizationandself-designarekeytowhole-ecosystemstudiesandoftendonotoccuratsmallerspaceandtimescales.Ecologicalfeedbackcausedbyorganisms(conceptsrediscoveredasecosystemengineersandtop-downcontrol),pulsescausedbyeventssuchasfireandfloods,andemergentecosystempropertiescausedbyhumanwastes,recycling,andhydrologicmodificationarekeyaspectsofthesestudies.\nreluctantlyconcludedthat:“whole-ecosystemexperimentsappeartobelosingfavorbecausetheyoftencannotbeexactlyreplicatedandareexpensiveanddifficulttoexecute,leadingtomanyecologiststofavorsmallscalesinordertoobtainthesatisfactionofstatisticalconfidence.”\n2.H.T.Odumandwhole-ecosystemstudies2.1.Texasshallowbayenclosure(1962–1963)Thedropnetapproachwasdiscontinuedwhenthecontractexpired,buttheapproachforquantifyingfishbiomassinadeepcoastalsystemwasaninnovativeattempttotrywhole-ecosystemsamplingwherenoonehadattempteditpreviously.\n2.2.Tropicalrainforestenclosure(1964–1967)2.3.Multi-seedingexperimentalestuarineponds(1968–1971)Estuarinepondswerebuilttoinvestigateecologicalchangesasthepondsreceivedsecondarilytreatedmunicipalwastewatersmixedwithsaltwater.Formally,thequestionbeingaskedwas“whethertheself-organizationprocess[ofspeciesarrangements]occursreadilytherewithnewconditionsfromwastewaterinfluenceandhowmuchtimeisrequired”\n2.4.WetlandsforrecyclingdomesticwastewaterinFlorida(1973–1978)nitrogenandphosphorusconcentrationsinthefoliageandbranchesofthetreesincreasedaswastewaterwasaddedanddecreasedagainafterthetreatmentstopped.\n4.Whole-ecosystemstudies—limitationsandadvantagesWhole-ecosystemstudiesandexperimentshavethedisadvantageofthelackofreplicationandthecostofdevelopmentandmaintenanceofthestudyorexperiment.ThetimeneededisusuallybeyondthatprovidedbyaresearchgrantingorganizationsuchastheNationalScienceFoundation(exceptionsaretheLong-TermEcosystemResearch(LTER)projects)andoftenbeyondaPh.D.student’stenureatauniversity.Theadvantagesarethattheentireecosystemispresentinthestudyandthattherearemoreopportunitiesforinteractandadaptiveresearch.Furthermore,incomparisonwithsmall-scaleexperimentsthatmayisolatecauseandeffectoneparameteratatime,theresultsachievedinawhole-ecosystemstudycouldbeclosertorealismthanthoseobtainedfromsimplifiedsmall-scalesystems.\n能值理论与分析方法（自学）\n专题讨论：群落生态及生态系统水平上的实验研究方法（4学时）例如：围隔实验（enclosuretest）；受控生态系统；能值理论与分析方法；