Permaculture for agroecology: design, movement, practice, and worldview. A review Rafter Ferguson, Sarah Lovell To cite this version: Rafter Ferguson, Sarah Lovell. Permaculture for agroecology: design, movement, practice, and world- view. A review. Agronomy for Sustainable Development, 2014, 34 (2), pp.251-274. 10.1007/s13593- 013-0181-6. hal-01234801 HAL Id: hal-01234801 https://hal.science/hal-01234801 Submitted on 27 Nov 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Agron.Sustain.Dev.(2014)34:251–274 DOI10.1007/s13593-013-0181-6 REVIEWARTICLE Permaculture for agroecology: design, movement, practice, and worldview. A review RafterSassFerguson&SarahTaylorLovell Accepted:17September2013/Publishedonline:25October2013 #INRAandSpringer-VerlagFrance2013.ThisarticleispublishedwithopenaccessatSpringerlink.com Abstract Agroecology is a promising alternative to industrial ismobilizingdiverseformsofsocialsupportforsustainability,in agriculture, with the potential to avoid the negative social geographicallydiverselocations.(5)Andscholarshipinperma- and ecological consequences of input-intensive production. culturehasalwaysbeenadiversemarginalsector,butisgrowing. Transitioningtoagroecologicalproductionis,however,acom- plexprojectthatrequiresdiversecontributionsfromtheoutside Keywords Permaculture .Farmdesign .Perennial of scientific institutions. Agroecologists therefore collaborate polyculture .Agroecologicaltransition .Diversifiedfarming with traditional producers and agroecological movements. systems .Agroecologicalmovement Permacultureisonesuchagroecologicalmovement,withabroad international distribution and a unique approach to system de- Contents sign. Despite a high public profile, permaculture has remained relativelyisolatedfromscientificresearch.Thoughthepotential 1.Introduction................................1 contributionofpermaculturetoagroecologicaltransitionisgreat, 2.Background................................3 it is limited by this isolation from science, as well as from 2.1ShiftingDefinitions...........................3 oversimplifyingclaims,andthelackofacleardefinition.Here, wereviewscientificandpopularpermacultureliterature.Asys- 2.2HistoricalContext............................3 2.3ConceptualInfluences.........................3 tematicreviewdiscussesquantitativebibliometricdata,including 2.4PermacultureandAgroecology.................4 keyword analysis. A qualitative review identifies and assesses 3.ReviewMethods................................5 majorthemes,proposals,andclaims.Themanuscriptfollowsa stratifieddefinitionofpermacultureasdesignsystem,bestprac- 3.1SystematicReview............................5 ticeframework,worldview,andmovement.Themajorpointsof 3.2QualitativeReview.........................7 our analysis are as follows: (1) Principles and topics largely 4.Results....................................7 complementandevenextendprinciplesandtopicsfoundinthe 4.1SystematicandBibliometricReview...........7 agroecologicalliterature.(2)Distinctiveapproachestoperennial 4.2QualitativeReview.........................11 polyculture, water management, and the importance of 5.Synthesis.................................16 agroecosystemconfigurationexceedwhatisdocumentedinthe scientificliteratureandthussuggestpromisingavenuesofinqui- 5.1SubstantiationandScholarship................17 ry. (3) Discussions of practice consistently underplay the com- 5.2LimitationsofthisStudy.....................18 plexity, challenges,andrisksthatproducersface in developing 5.3FutureDirections...........................19 diversifiedandintegratedproductionsystems.(4)Themovement 6.Conclusion................................20 R.S.Ferguson(*) 1Introduction 1105PlantSciencesLaboratory,UniversityofIllinoisat Urbana-Champaign,1201S.DornerDr.,Urbana,IL61801,USA e-mail:[email protected] Increasing concerns about the negative impacts of industrial agriculture have generated a vigorous debate over the feasi- S.T.Lovell bilityoftransitiontoalternativeformsofagriculture,capable 1009PlantSciencesLaboratory,UniversityofIllinoisat Urbana-Champaign,1201S.DornerDr.,Urbana,IL61801,USA of providing a broad suite of ecosystem services while 252 R.S.Ferguson,S.T.Lovell producingyieldsforhumanuse.Thetransitiontodiversified, researchers, stakeholders, and land users. Permaculture con- ecologically benign, smaller scale production systems is tributestoanappliedformofecologicalliteracy(Orr1992), addressed in the literature of agroecology (De Schutter supplying a popular and accessible synthesis of complex 2010), diversified farming systems (Kremen et al. 2012), socioecologicalconcepts.Thedesignorientationofpermacul- and multifunctional agriculture (Wilson 2008). ture offers a distinctive perspective that suggests avenues of Agroecological transition must be regarded as a complex, inquiry in agroecosystem research. Lastly, these factors are multi-sectorproject,operatingatmultipletemporalandspatial embodiedinaninternationalmovementthatoperateslargely scalesandinvolvingdiverseconstituencies(GeelsandKemp outside of the influence and support of large institutions, 2007; Marques 2010; Piraux et al. 2010). For this reason, whichsuggestsopportunitiesforparticipatoryactionresearch researchershaveoftendirectedtheirattentionoutsideofinsti- andthemobilizationofpopularinquiryandsupport(Méndez tutionalsciencetodocumentthecontributionsthattraditional etal.2013). and innovative practices offer to the process of transition Thepotentialofpermaculturetocontributebroadlytoagro- (Altieri 2004; Ingram 2007; Rocha 2005; Koohafkan et al. ecological transition is limited by several factors. Of primary 2012; Rosset et al. 2011). Alternative agroecology move- importance is the general isolation of permaculture from sci- ments, for example, have been critical in the process of re- ence,bothintermsofalackofscholarlyresearchaboutperma- gional agroecological transition (Nelson et al. 2009; Altieri culture and neglect within the permaculture literature of con- andToledo2011)andlikelywillbeinthefuture(Fernandez temporary scientific perspectives. This deficit is compounded etal.2012;Petersenetal.2012). by overreaching and oversimplifying claims made by move- This paper addresses the alternative agroecology move- ment adherents and the absence of any systematic multisite ment called permaculture and its potential contributions to assessmentofpermaculture'simpacts.Additionally,thedifficul- agroecological transition. Permaculture is an international tyofprovidingaclearanddistinguishingdescriptionofperma- movement and ecological design system (Fig. 1). Despite culturecancauseconfusionandhinderrigorousandsystematic permaculture'sinternationalextentandrelativelyhighpublic discussion. profile, it has received very little discussion in the scientific The objective of this paper is to contribute to a better literature.Thetermoriginatedasaportmanteauofpermanent understanding of the substance, strengths, and limitations of agricultureandisdefinedbyco-originatorDavidHolmgrenas permacultureasapotentialcontributortoagroecologicaltran- “Consciously designed landscapes which mimic the patterns sition. Introductorymaterialincludesabriefoverviewofthe and relationships found in nature, while yielding an abun- origins and development of permaculture, the growth of the danceoffood,fibreandenergyforprovisionoflocalneeds” movementovertime,andapreliminaryheuristicforcompar- (2004, p. xix). As a broadly distributed movement with a ing the prominence and overlap of permaculture and agro- distinctive conceptual framework for agroecosystem design, ecology across several sectors. The introduction is followed permaculture'srelevancetotheprojectofagroecologicaltran- byasystematicreviewofscientificandpopularpermaculture sition has several aspects. Permaculture can function as a literature,analyzingpublicationtype,date,andlocation,topic framework for integrating knowledge and practice across location, scholarly discipline, and citations. Systematic anal- disciplines to support collaboration with mixed groups of ysisalsoincludesquantitativecontentanalysisusingaconcept a b Fig.1 Examplesofproductionandeducationinthepermaculturemovement.aSmallfarmwithintercroppedannualsandperennials,workedpartially withhandlabor.bWorkshoponthedesignandmaintenanceofperennialpolycultures Permacultureforagroecology:design,practice,movement,andworldview 253 network approach. Qualitative review of the permaculture and appropriate technology (Pursell 1993) emerged as move- frameworkthenidentifiesandevaluatesprominentthemesin mentsanddisciplinesoftheirown.Otherandolderapproaches, thepermacultureliterature,focusingonagroecologicaltopics. such as organic farming, experienced rapid growth and wide- Finally, qualitative and quantitative analyses are synthesized spreadacceptance(Lockeretz2007).Manyofthesealternative to produce an overall evaluation of permaculture, including frameworks nowapproach the mainstream, through the incre- recommendationsforfuturedirectionsforresearchanddialog. mentalaccumulationofscientificevidence,institutionalization, or as in the case of organic farming through certification and large-scalecommercialization. 2Background Permaculturewasfoundedinthe1970sbyBillMollisonand David Holmgren and now has a presence on every inhabited 2.1Shiftingdefinitions continent.Permaculture'sfounderssharedbroadenvironmental concernswiththemovementsdescribedabovewhilefocusing The definition of permaculture varies among sources and specificallyonthethreatofenergyscarcityforenergy-intensive displays an expansion in subject area over time. In 1978, agriculturalsystems(MollisonandHolmgren1978).Mollison permaculturewasdefinedinthefoundingtextas“anintegrat- andHolmgrendrewonmanysourcesintheirdevelopmentof ed,evolvingsystemofperennialorself-perpetuatingplantand thepermacultureframework,butwereespeciallyinfluencedby animalspeciesusefultoman…inessence,acompleteagri- the British and US literature of permanent agriculture and the cultural ecosystem, modeled on existing but simpler exam- systems ecology/ecological engineering perspective of H.T. ples” (Mollison and Holmgren 1978, p. 1). By 1988, the Odum(MollisonandHolmgren1978;Holmgren2004). definition had grown in scope to encompass broader issues of human settlement while maintaining a core agricultural 2.3Conceptualinfluences focus:“Permaculture…istheconsciousdesignandmainte- nanceofagriculturallyproductiveecosystemswhichhavethe 2.3.1Permanentassustainableandperennial diversity, stability, and resilience of natural ecosystems. It is theharmoniousintegrationoflandscapeandpeopleproviding Thetermpermanentagriculture,fromwhichthewordperma- theirfood,energy,shelter,andothermaterialandnon-material cultureisderived,hasmultipleuses.Permanentagricultureis needs in a sustainable way” (Mollison). While permaculture usedtocontrastsedentary,continuousagriculturewithshifting addresses multiple aspects of human settlement, this paper cultivation in discussions of the latter (q.v. Rasul and Thapa willfocusprimarilyonthoseaspectsofpermaculturerelevant 2003;GeistandLambin2002).ExaminationoftheBritishand toagricultureandagroecologicaltransition. USliteratureonfarmingpracticesintheearly1900ssuggests thattheword“permanent”wasusedinananalogousfashionto 2.2Historicalcontext the current use of the term sustainable (King 1911; Howard 1940). With the publication of Russell Smith's foundational Permaculture emerged in parallel with other movements and agroforestry text Tree Crops: A Permanent Agriculture, per- disciplineswithafocusonsustainability.Inthepast50years, manent came to connote agricultural systems incorporating a concernsoverthenegativesocialandenvironmentalimpactsof high proportion of perennial species (Smith 1929). It is this urbanization,industrialagriculture,andresourceextractionand concept for which permaculture is named. Mollison and depletion have expanded dramatically (De Steiguer 2006; HolmgrenadoptedSmith'semphasisontheimportanceoftree Hawken 2007; McCormick 1991). Over this period, public cropsforsoilstabilizationinhillsideagriculture,productionof andscientificconcernforenvironmentaldegradationhasspread fodder,andproductionofcomplementaryandstaplefoodsfor from isolated voices, through environmental movements and humanconsumption(MollisonandHolmgren1978).Theport- emergingscientificdisciplines,andintomainstreamscienceand manteau of “permanent agriculture” was later redefined as popular culture (FitzSimmons et al. 1991). Environmental “permanent culture” as the scope of permaculture expanded movement participants have produced diverse proposals for from the design of smallholder agriculture to encompass hu- alternativefoodproduction(Lockeretz2007),internationalde- mansettlementmorebroadly(Mollison1988). velopment (Dahlberg 1979; Cole 1981), generating energy (Clark 1975), and planning settlements (Alexander 1977). In 2.3.2Systemsecology parallel, and often intersecting with, the proposals of environ- mentalandsocialmovements,scientists,anddevelopmentpro- Permaculture's emphasis on whole systems design is heavily fessionalshaveproposedalternativeframeworksformanaging influenced by the work of ecologist H.T. Odum (Holmgren natural resources and fostering economic development. 1992).Odumdevelopedtheinfluentialframeworkofsystems Throughthe1970sand1980s,agroecology(WezelandSoldat ecology,athermodynamicperspectivethatregardsecosystems 2009),agroforestry(Nair1993),ecologicaldesign(Todd2005), as networks through which energy flows and is stored and 254 R.S.Ferguson,S.T.Lovell transformed,whichcanbediagramedandmodeledinamanner by Holmgren and Mollison (Mulligan and Hill2001, p. 202), analogousto electronic circuits(Odum 1994).Odumreferred whoadoptedmanyoftheconceptsoftheKeylineplandirectly totheappliedformofsystemsecologyasecologicalengineer- into the developing permaculture framework (Mollison and ing, and this design perspective would shape fundamental Holmgren1978;Mollison1979). components of the permaculture perspective (Holmgren 2004). In the highly cited book Environment, Power, and 2.4Permacultureandagroecology Society (1971), Odum proposes an approach to the design of novelandproductiveecosystemsinwhichspeciesareregarded In the past three decades, permaculture has grown in parallel as distinctive but interchangeable system components which with agroecology, displaying overlapping concerns while de- should be selected from a global pool without regard to the velopingdifferentconstituencies.Permacultureshareswiththe placeoforigin.Inthisview,thedistinctiveinputsandoutputs disciplineofagroecologyafocusontheintersectionofecology of each species will connect in novel assemblages, and the and agricultural production, a normative orientation toward exchanges of energy and resources between system compo- agroecological transition, and an association with popular nents will substitute for human labor and material inputs. movements consisting largely of land users. Despite these Ecosystem designers should therefore foster self-organization parallels, permaculture has received very little discussion in through the iterative “seeding” of diverse species from the theagroecologicalliterature.Whenpermacultureismentioned, globalspeciespool,inordertogenerateandselectecosystems itisfrequentlyfoundasanitemonalistofalternativeagricul- whichproduceyieldsforhumanusewithminimallaborinput tural frameworks, the value of which is either explicitly in (Odum1971,p.280).Theinfluenceofthisfocusonfunctional question (Gomiero et al. 2011; Pretty 2006; Bavec et al. relationships between components, the self-organization of 2009;Pretty2005),orpositivebutnonspecific(Leakey2012; systems,andspeciesselectionpracticesisreflectedthroughout Debetal.2008;Lovelletal.2010).Permacultureiselsewhere the permaculture literature (Mollison and Holmgren 1978; associated positively, albeit in passing, with agroforestry, pe- Mollison1988;Holmgren2004;Hemenway2009). rennialpolycultures,agroecosystemdesign,ecosystemmimic- ry,andagrobiodiversity(FrancisandPorter2011;TorreUgarte 2.3.3Keylineplanning and Hellwinckel 2010). Substantive assessment of permacul- ture as an approach to agriculture, positive and negative, ap- Holmgren and Mollison were also informed by the whole pearstobeabsentfromthepeer-reviewedliterature. landscape approach of the Australian Keyline design system Thisabsenceissurprisinginlightofpermaculture'sinterna- (Holmgren 2004). From the 1950s to the 1970s, farmer and tionalpublicprofile.Parallelqueriesofonlinedatabasesforthe writerP.A.Yeomansdevelopedasystemthatintegratednovel terms “permaculture” and “agroecology” can be used to illus- methodsforlandscapeanalysiswithwholefarmwatermanage- trate patterns in the relative prominence and overlap of each ment, agroforestry, soil building strategies (using slightly-off- field across sectors. This fairly crude comparison is presented contour chisel plowing and rotational grazing), and the devel- here (Fig. 2) in a preliminary fashion to demonstrate that the opment of new chisel plow designs for use in the system sparserepresentationofpermacultureinthescientificliterature (Yeomans1954,1958,1971,1981).Yeoman'sKeylinesystem is incommensurate with a high level of general interest. The has received very little attention in the scientific literature. proportions of results returned for each term varied widely Keyline planning is nevertheless an innovative application of across data sources. The scientific databases Web of designtoagriculturallandscapesandshapedtheapproachtaken Knowledge and Google Scholar returned 21 and 6 times as Fig.2 Proportionalresultsfrom parallelsearchqueriesfor “agroecology”(crosshatch), combined“agroecology”+ “permaculture”(solid),and “permaculture”(horizontals),to multipleonlinedatasources, illustratingtheunevenrelative prominenceofagroecologyand permacultureacrossdifferent sectors.Numbersinparentheses indicatecombinedtotalresponses fromeachdatasource Permacultureforagroecology:design,practice,movement,andworldview 255 manyresultsforagroecologyasforpermaculture,respectively, review will then address questions of topic, theme, and as- whilegeneralpurposeinternetsearchenginesGoogleandBing sessmentintermsofcurrentscientificunderstanding,inorder wereskewedintheoppositedirection,returning11and7times toevaluatetheactualandpotentialcontributionsofpermacul- asmanyresultsforpermacultureasforagroecology,respective- turetoagroecologicaltransition. ly. Multipurpose literature databases for book sales were less asymmetrical,withapproximatelyequalresultsforeachtermin 3.1Systematicreview Google Books and twice the results for permaculture in Amazon.Documentarchivesofinternationaldevelopmentor- A systematic review methodology used in numerous previous ganizations(USAID,PeaceCorps,andFAO)werehighlyand studieswasadaptedforapplicationtothebodyofpermaculture heterogeneously skewed, respectively, returning 3 times the literature (Guitart et al. 2012; Wezel and Soldat 2009). The resultsforagroecologyasforpermaculture,41timestheresults permacultureliteraturediffersfrommostsubjectsofsystematic forpermaculture,and21timestheresultsforagroecology. reviewinthelargenumberofpublicationsintendedforapopular In addition to the parallels described above, permaculture audience, the large number of book-length publications, the shareswithagroecologyacomplexstratifieddefinition.Recent small number of peer-reviewed works, and the absence of ex- scholarshiphasclarifiedthatagroecologysimultaneouslyrefers perimentaldesignandstatisticalanalysisfromalmostallworks. to a scientific discipline, a social movement, and a set of agricultural practices (Wezel et al. 2009). Similarly, some of 3.1.1Searchprotocol the confusion surrounding permaculture may be attributed to the use of the term to refer to a design system, to an interna- Parallel searches were conducted on Web of Knowledge tionalmovement,totheworldviewcarriedbyanddisseminated (WOK),GoogleScholar,InternationalInformationSystemfor by the movement, and to the set of associated practices. the Agricultural Sciences and Technology (AGRIS), and Figure3isaconceptualmapintendedtoclarifytherelationship Education Resource Information Centre (ERIC), using the amongthedifferentstratathatmakeuppermaculture,eachof search term permaculture. In the case of Google Scholar, the which intersects with the project of agroecological transition. searchwasconstrainedtoarticleswiththesearchtermappearing Thisconceptualstructure will be used to organize theexami- inthetitlefield.Whilethiscriterionexcludedmanyworksthat nationandassessmentofthepermacultureliterature. substantivelypertaintopermaculture,itavoidedincludingany worksforwhichtherelationshipwithpermaculturewasambig- uousortrivial.Effortwasmadetoeliminateself-publishedand 3Reviewmethods exclusivelyelectronicworks,unlesstheywerelistedashaving beencitedwithinGoogleScholar,inordertofocusonpublica- Thisstudyintegratesmultiplereviewmethodstoaddressthe tions for which there was some evidence of readership. challenges of assessing and synthesizing a large and diverse Academic theses and dissertations were exempted from this literature,muchofwhichisintendedforapopularaudience. consideration.ForWOK,AGRIS,andERIC,publicationswith Intheabsenceofanypreviousreviews,itisusefultoaddress permacultureappearinginanyfieldwereincluded.References quantitative questions of what has been published, in what forbookreviewsofworksappearingelsewhereinthebibliog- form,where,andaboutwhatgeographicregions.Qualitative raphywerenotincluded.Thesearchprotocolwasconcludedon 18December2012.Resultsincludedprepublicationdataonone book chapter slated for publication in April 2013, and the terminalyearofthebibliographyistherefore2013. WhilethisstudyaddressesEnglish-languageliteratureonly, a supplementary search protocol was used for the preliminary identification of concentrations of permaculture literature in other languages. Language localizations of Google Scholar werequeriedinSpanish,Portuguese,German,French,Arabic, Japanese, and Russian, and the number of search results was recorded and compared to results for the English-language search.Nootherdatawerecollectedfornon-Englishliterature. Fig.3 Stratifieddefinitionofpermaculture,illustratingtherelationships 3.1.2Bibliometricanalysis between four common referents of the term. Permaculture is (1) an internationalandregionalmovementthatdisseminatesandpractices(2) Thesearchprotocoldescribedabovewasusedtoassemblethe adesignsystemand(3)abestpracticeframework.Thedesignsystemand bestpracticeframeworkarecontextualizedby(4)theworldviewthatis bibliographyforanalysis.Aftertheeliminationofduplicateand carriedbythemovement spurious results, the bibliography contained 230 references. 256 R.S.Ferguson,S.T.Lovell Table1 Publication Each reference in the bibliography was identified as book, typesinpermaculture Publicationtype Number journal article, graduate thesis, book chapter, conference pro- bibliographyassembled foranalysis Journalarticle 50 ceeding,periodicalarticle,ormiscellaneous(Table1).Journal Thesis 46 articlesincludedpeer-reviewedandnon-peer-reviewedworks. Book 41 Periodicalarticlesincludedmagazine,newspaper,andnewslet- Periodicalarticle 28 terarticles.Scholarlyandtechnicalpublicationswereidentified as a subset of total publications. Peer-reviewed publications Proceedings 27 wereidentifiedasasubsetofscholarlypublications. Chapter 15 For scholarly works (including refereed and non-refereed Report 11 publications), the discipline of the journal (for articles), the Miscellaneous 12 academicprogram(forthesesanddissertations),ortheconfer- Booklet 5 ence(forproceedings)wasdetermined.Whentheinstitutional Presentation 2 discipline could not be determined, the discipline of the au- Meetingabstract 1 thor(s)ortheapparentdisciplineofthepublicationtopicwas Undergrad,non-thesis 1 used. Disciplines were sorted into categories according to a Occasionalpaper 1 three-tiereddisciplinarytaxonomythatsynthesizessevenother Interview 1 majordisciplinarytaxonomies(bepress2010).Citationstatis- Seedcatalog 1 tics were recorded for each reference. As the majority of the Total 230 references in the bibliography appeared solely in the Google Fig.4 Distributionofpublication typesina230-reference bibliographyofpermaculture,in 5-yearincrementsexceptfor 2008–2013.a Distributionof publicationtypeswithinthe biographyshowsrapidgrowthin articlesandthesessince2008. bScholarlypublications representagrowingshareofthe totalbibliographyovertime,with peer-reviewedpublications growingataslowerpace Permacultureforagroecology:design,practice,movement,andworldview 257 Scholar searches, citation statistics were derived exclusively whilecolorandgroupingshowthemostsignificantcontexts fromGoogleScholarqueries.Thebibliographywasanalyzed inwhich eachterm appears.Edge thickness was determined for two geographic values: place of publication and place of by weight—the frequency of the word pairs represented by topic.Placeofpublicationdatawasobtainedforallreferences, each node. Only 100 most significant nodes from each time andaplaceoftopicwasidentifiedin135references. frame,byBC,arerepresentedineachgraph.Alledgeswitha weightof1,signifyingthatthewordpairtheyconnectedonly 3.1.3Conceptnetwork co-occurredinasingleinstance,werefilteredfromthevisu- alizationtoenhancereadability. Keywordsforeachreferenceweredrawnfrommultiplefields toaccommodatethediversityofpublicationtypesrepresent- 3.2Qualitativereview ed. Title keywords were included for all publications, and author keywords were included whenever present. Abstracts Thetextsexaminedforqualitativeanalysisincludedaddition- wereincludedforscholarlyarticleswheneveravailable.Jacket alpublications, notincludedinthe bibliography, selectedon blurbs were included for books whenever available. Textual thebasisofauthorshipbykeymovementfigures,referencein analysiswascarriedoutwithwordco-occurrenceanalysis(He influential works inthe bibliography, or special relevance to 1999)usingaconceptnetworkapproach(Popping2003)that themes identified in ongoing analysis. Qualitative analysis incorporatesanalysisofprobabilisticwordco-occurrencewith alsodrawsonadditionalnonprintsources,includingwebsites, relative word position and represents relationships between online discussion platforms, and video. Sources were exam- keywords as a network graph. This quantitative approach to ined for prominent themes with a bearing on agroecological textanalysisallows for the exploratory analysisofmeaning, transition and assessed in relationship to contemporary sci- context,and changeovertime,inlargebodiesoftext, while ence.Results fromthesystematicreviewwereusedtotrian- providinganalternativeorcomplementtoqualitativecoding gulatewithandinformqualitativeanalysis. (He 1999). Keyword text was analyzed in four time frames: Thehighlevelofredundancyinthepermacultureliterature the three sequences of 1978–1992, 1993–2002, and 2003– hasbeennotedelsewhere(Scott2010),suchthatasignificant 2013andalsoasacompletesequenceof1978–2013.Thetext portionofpublicationsdevotesomespacetoreiteratingfoun- ofeachsequencewassubmittedindividuallytotheweb-based dational materialdeveloped ina small number ofkey publi- analytical engine Textexture (http://textexture.com/). cations (Mollison and Holmgren 1978; Mollison 1988; Textextureperformsseveralpre-analysisprocesses,including Mollison and Holmgren 1978; Holmgren 2004). Key publi- the removal of common and semantically trivial words (in- cationswillbecitedwhentheintentistoclarifyorigins,while cluding articles, conjunctions, modifiers, etc.) and stemming multiplederivativepublicationswillbecitedwhentheintent words using the Krovetz Stemmeralgorithm toreducecom- istoillustrateprevalence. plexity and redundancy between closely associated words (Paranyushkin 2011). Once the text is prepared, Textexture performsatwo-passanalysistoconverttextintonetworkdata. 4Results Scanning first in two-word and then in five-word units, Textexture creates a node for each novel word it encounters 4.1Systematicandbibliometricreview and creates or strengthens links between nodes each time words co-occurwithina scanningunit(Paranyushkin2011). Inthissection,the resultsofthe systematicand bibliometric Textexture providesits own visualization engine, but for the analyses are presented, including publication type, citations, purposes of this study, the graph data was downloaded as a publication and topic geography, scholarly discipline, and Graph Exchange XML Format file and visualized using the conceptnetwork. open-source graphing software Gephi (Bastian et al. 2009). Once loaded into Gephi, each of the four graph files was 4.1.1Publicationtype processed identically. Nodes were sized according to the betweennesscentrality(BC)metric,whichmeasuresthenum- Thethreemostprolificpublicationtypesinthebibliography ber of node pairs whose shortest connecting path passes werejournalarticle(50),graduatethesis(46),andbook(41). through the target node (Brandes 2001). Nodes were then While journal articles and theses are most numerous, when clustered using a community detection algorithm based on publication length is considered, it is clear that books repre- modularity, which identifies groups of nodes whose mutual sent the bulk of published content on permaculture. Along connectionsaredenserthantheirconnectionstotherestofthe withoverallgrowthinpublications,thedistributionofpubli- network (Newman 2006; Paranyushkin 2011). Each cluster cationtypeschangesovertime(Fig.4a),andthethreepubli- was assigned random colors. The size of nodes therefore cationtypesshowingthemostgrowthinperyearpublications shows the number of contexts in which each term appears, werejournalarticles(from0to21),graduatetheses(0to20), 258 R.S.Ferguson,S.T.Lovell 4.1.2Geographyofpublicationandtopic English-language permaculture literature originates predomi- nantly from the USA, Australia, and the UK (Fig. 6a). The geographicdistributionofpermaculturewritinginthebibliog- raphyhasbecomemorewidelyspreadovertime:49%from Oceania (Australia and New Zealand) and 41 % North Americain1978–1987and43%fromNorthAmerica,34% Europe,9%Oceania,6%Africa,and9%Asiain2008–2013. Sixtypercentofthereferencesinthebibliographycouldbe determinedtohaveageographicallyspecifictopic.Asinthe geographic distribution of the publishing, the topics of per- maculturepublicationswereinitiallyconfinedtotheUSAand Australia and became more widely distributed over time Fig.5 Distributionofacademicdisciplinesamong122scholarlypubli- (Fig. 6b). In 2008–2013 period, 35 % of publications in the cationsaddressingpermaculture.Agroecologyandcloselyrelateddisci- bibliographyreferredtoNorthAmerica,8%toOceania,22% plines (grouped within life sciences) represent a minority of scholarly toEurope,18%toAfrica,6%toLatinAmerica,6%toSouth workinpermaculture Asia,4%toEastAsia,and2%toWestAsia. For references with geographically specific topics, both countryofpublicationandcountryoftopicwereclassifiedas andbookchapter(0to11).Themajorityofthepermaculture “developed”or“developing,”usingtheHumanDevelopment literature is written by non-scientists for a popular audience. Index(Malik2013).Countriesinthe“veryhighhumandevel- Scholarlyworks,andthesubsetofpeer-reviewedpublications opment”categorywereclassifiedasdeveloped,andcountries withinthatcategory,arepresentasaminorityofpublications intheotherthreecategorieswereclassifiedasdeveloping.Of throughout the bibliography, representing 54.3 and 13.9 %, the135referenceswithgeographicallyspecifictopics,95were respectively. The total share of scholarly and peer-reviewed classifiedasdomestic,withpublicationandtopictakingplace publicationshasfluctuatedwhilegrowingovertime(Fig.4b), in the same country, and 41 classified as international. Of from33%from1978to1982to71%from2008to2013. domestic references, 76 were from the developed world and The 122 scholarly publications in the bibliography are 19 from the developing world. Of the 37 international refer- distributed across a broad set of natural and social scientific ences published in the developed countries, 17 dealt with andprofessionaldisciplines(Fig.5).Themostprevalentdis- topics in developed countries, while 21 examined topics in ciplinary categories, in descending order, are social and be- developing countries. Of the three international references havioralsciences(41),lifesciences(28),architecture(23),and published in the developing world, two examined topics in education(14). developed countries, and two examined topics in developing Fig.6 Geographicdistributionof a aplaceofpublicationandbsites discussedastopicsin permaculturepublicationsover time b Permacultureforagroecology:design,practice,movement,andworldview 259 Fig.7 Network representation of country-by-country relationships publicationsoriginatingfromthatcountry.Nodecolor isaheatmap between placeofpublication and place oftopicin a 135permacul- representing number of publications with topics specific to that ture publications. The network illustrates a pattern in which devel- country, with green indicating few and red indicating many. Links oped countries commonly study developing countries, and the re- betweennodesrepresentpublication/topicrelationships,withnumberof verse is seldom true. Node size is scaled to indicate the number of publicationsindicatedbylineweight countries—with one of the references dealing with topics in Queries to multiple language localizations of Google both a developed and a developingcountry. The country-by- Scholar returned results concentrated in English-language country relationship between publication and topic is repre- literature.With7,190searchresults,resultsinEnglishrepre- sented as a geographic network in Fig. 7, while the propor- sented59%ofthetotalresults.Indescendingrank,returnsfor tional distribution of geographic publication–topic relation- other languages were Spanish (2,190), Portuguese (1,980), shipsisshowninFig.8. German(294),French(267),Arabic(95),Japanese(44),and Russian(30).PastresearchhasidentifiedanEnglish-language biasinGoogleScholar(KoushaandThelwall2008;Neuhaus etal.2006).Interpretationoftheseresultsisthereforelimited totheobservationthatasignificantminorityofpermaculture literature is in languages other than English and is not addressedinthisstudy. 4.1.3Conceptnetwork The network graph produced from the complete series of references, from 1978 to 2013, contained 1,330 edges, with each edge representing the co-occurrence of one word pair. Figure9showsthefull100-nodenetworkforeachtimeinterval and the complete set, illustrating the changing centrality and contextual significance of key terms over time and in aggre- Fig.8 Theproportionaldistributionofgeographicrelationshipsbetween gate.Themodularityalgorithmproducedsixconceptualclus- placeofpublicationandplaceoftopicin135referencesinthepermacul- tersinthecompletesequence,eachdenselylinkedtoacentral turebibliography.“Domestic”describesresearchthatisconductedand publishedwithasinglecountry.“International”describesresearchthatis termandtoeachother(Fig.9d).Thecentralterms,indescend- conductedinoneormorecountriesandpublishedelsewhere ing order of importance (by BC), were design, community,
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