Permaculture for agroecology - Liberation Ecology

24 Pages·2013·1.84 MB·English

Agron.Sustain.Dev.
DOI10.1007/s13593-013-0181-6
REVIEWARTICLE
Permaculture for agroecology: design, movement, practice,
and worldview. A review
RafterSassFerguson&SarahTaylorLovell
Accepted:17September2013
#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
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
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
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
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.
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
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),
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
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,
R.S.Ferguson,S.T.Lovell
Fig.9 Conceptnetworkmapsofkeywordsfrompermaculturepublica- denotesconceptualclusteroftightlyinterlinkedconcepts.aPublications
tions.Nodesize denotescentralityofconcepts,links representconcept 1978–2002(N=51).bPublications1993–2002(N=115).cPublications
co-occurrence,linkwidthrepresentsco-occurrencefrequency,andcolor 2003-2013(N=157).dCompleteseries1978-2013(N=230)
sustainable,farm,study,andresource.Thenetworkproduced identified eight conceptual clusters, organized around the fol-
fromthetextofthefirstsequenceofreferences,from1978to lowing terms: design, agriculture, present, urban, resource,
1992,contained526edges(Fig.9a).Themodularityalgorithm create,base,andhousing.Thefivemostcentralclustersineach