The Cultural Keystone Concept: Insights from Ecological AnthropologyAuthor(s): Simon Platten and Thomas HenfreySource: Human Ecology, Vol. 37, No. 4 (Aug., 2009), pp. 491-500Published by: SpringerStable URL: http://www.jstor.org/stable/40343990 .Accessed: 05/11/2014 09:25Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp .JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org. .Springer is collaborating with JSTOR to digitize, preserve and extend access to Human Ecology.http://www.jstor.org This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and ConditionsThe Cultural KeystoneConcept: Insights from Ecological Anthropology Hum Ecol (2009) 37:491-500 DOI10.1007/sl0745-009-9237-2 SimonPlatten Thomas Henfrey Publishedonline:28 May 2009 Springer Science + Business Media, LLC 2009 AbstractThe concept of the keystonespecies has a long history in ecologicalanalysis,although its validity remains controversial. Anthropological researchershave recently coined the termcultural keystonespecies, but have not demonstrated any significant differencesfrom existing treatmentsof culturallyimportantspecies. We define cultural keystonesaccording to their systemicfunction, as having essentialrolesin maintainingany levelof complex- ity withina social-ecologicalsystem.Examples include bittercassava consumptionamong lowlandSouthAmerican groups suchas the Wapishana in Guyana, and commercial cultivationof carrotsin Rurukan Village in Minahasa, Indonesia.These examples arebothessentialat one levelof systemicreproduction: withinthe domesticand village economy in the cassava case, and carrotswithin regional markets.While each is centred upon a singlebiological species, thecultural keystone itselfis notthis species, buta complexincorporating severalmaterialand non-material system elements. Keywords Cultural keystonespecies Cultural significance Biocultural diversity Social-ecological systems Ethnobiology The KeystoneMetaphor in Ecology In a stone arch, the keystone is themost importantelement, and is functionallyirreplaceable. Remove any other stone, and theresultis a smaller arch, or one of different shape. Removethe keystone, and the capacity to forman arch goes withit. Fromthe remaining stonesone can make a stack, a wall or a pile: any numberof structurallysimpler forms. Paine (1969) introducedthe keystonemetaphor intothe ecologicalliterature,describing theeffectsof predationby thesea starPisasterochraceuson thestructureof intertidal ecosystems. Removalof the sea starleads to competitive exclusion among its preyspecies and considerableloss of diversity in the ecosystem. P. ochraceusthus performs a unique ecological functionessentialto maintaining the system in a more complex(in this case, speciesrich) state (Paine 1966, 1969). Replication of Paine's removal experi- mentsshowedthesea star's keystone statusis not universal, but manifest only under certain ecological conditions (Menge et al 1994). Ecological keystone functionsare not inherentto any particularspecies, but dependupon context. While Paine's (1969)original use of the keystone metaphor restrictedit to top predators, others have subsequently used it to referto species at other trophic levels or fulfilling other ecologicalroles,includingprey, mutualists,hosts, habitatmodifiersand herbivores (Mills et al 1993; more recent examples includeWillsonand Halupka1995;Knapp etal 1999; Milleretal 2000). Other writershave extendedit beyond individual species to processesinvolving abiotic as well as biotic ecosystem elements (Bond 1994), guilds (Terborgh1986), micro- habitats (Levey 1990), and multispeciescomplexes(Daily et al 1993). Debate persists,notably in the journalEcology ) Springer S. Platten Department of Anthropology,University of Kent, Canterbury, UK e-mail: s.j.platten@kent.ac.uk T. Henfrey{M) Department of Anthropology, Durham University, Durham, UK e-mail: t.w.henfrey@durham.ac.uk This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and Conditions492 Hum Ecol (2009) 37:491-500 species. As faras we are aware, thefirst publishedexample to extendthe keystonemetaphor in this way derivesfroma study ofthe ecological andcultural importance ofironwood (Olneyatesota) treesin theSonoranDesertof Southwestern NorthAmerica (Nabhan and Carr 1994): "Ironwoodis considerednot only a keystonespecies in itsdesert habitat, but also a cornerstoneto the crafts-basedeconomiesof SeriIndianand Mexicancommunitiesof Sonora,Mexico", (St. Antoine1994: 70). This usage of the termis purely metaphorical, and is not accompaniedby any attempt towardsa systematic definitionof cultural keystones. Precedentsfora formalisationof the cultural keystone concept lie in various attempts to identifyspecies of par- ticularcultural importance - whether symbolic, utilitarian or economic - as culturally salient.One attempt at quanti- ficationof this phenomenon isan index of cultural significance based on awardingpoints in various categories (Turner 1988). Adapted to increase its cross-cultural relevance, thishas beenusedto helpprioritiseplantspecies and habitatsfor protection(Stoffle et al 1990). Garibaldiand Turner (2004a) extendthe concept of salience in defining "cultural keystonespecies" as "the culturally salient species that shape in a majorway the cultural identity of a people, as reflectedin thefundamental rolesthese species have in diet,materials, medicineand/or spiritualpractices".Many workershave enthusiastically - and uncritically - adopted this concept as an indicatorof cultural importance(Byg et al 2006; Gelcichet al 2006; Stercho 2006). Others emphasise itsvalue as a conceptual and practical tool for linkage betweennaturaland social sciences approaches in conservation (Higgs 2005; Ticktin et al 2006). Whilethe insight thata keystonemetaphor can be useful in the study of culturalformationsis avaluable one, Garibaldiand Turner'sdefinitionbearscriticismon several grounds. It is not clear how, if at all, cultural keystone species differfromthosethatare simplyculturally salientor economicallyimportant(cf. Davic 2004). In addition, we do not considerthemto have adequately demonstrateda claimof metaphoricalsimilarity to the ecologicalkeystone concept,upon which theyjustify theiruse of the term (Garibaldi andTurner 2004b). On a different note, Garibaldi andTurner (2004a) propose use ofa quantitative indexto aid identificationof cultural keystonespecies, an approach we consider fundamentally flawed.One reportedattempt to use thesecriteriafoundthem impractical(The Snow Leopard Conservancy2007). Cristanchoand Vining(2004) avoid spuriousquantifi- cation in their alternative,independent treatmentof the cultural keystoneconcept,identifying seven criteriaas diagnostic,though not definitive, of "culturally defined keystonespecies". Like Garibaldiand Turner,theygive no clearindicationas to what distinguishes cultural keystones and Society, betweenthose who employ the keystone conceptbroadly(De Leo and Levin 1997; Khanina 1998; Vanclay1999; Higdon2002), and otherswho considerit over-extended (Piraino and Fanelli 1999; Davic 2000, 2002, 2003). Some critics go further, and considerthe keystoneconcept too vague and empirically unsoundto be useful (Mills et al 1993; Hulbert 1997). A returnto thenarrowdefinitionof ecologicalkeystones suggestedby Paine's researchremainstrueto the original architectural metaphor in which the keystone affects physical interactions among stonesbelow it so as to ensure that they are mutuallysupporting.However, it wouldbe an errorto read too much significance intowhatis no more thana fortuitouscoincidencewiththe spatialmetaphors used to describe trophic relations.Modern concepts of ecosystem structureand dynamicssuggest thata broader concept of keystones can play an importantconceptualrole, of which the cleareststatementis Holling's extended keystonehypothesis, "All ecosystems are controlledand organisedby a small numberof key plant,animal, and abiotic processes thatstructurethe landscape at different scales" (Holling 1992: 478). Identifyingkeystones in practice is moredifficult.The key organisational roles identified by Holling cannotbe reduced to functional non-redundancy(Schulze and Mooney 1994: 502; Grimm1995: 9-10), nor ecological dominance (Power et al 1996). Amore sophisticated definitionof a keystonespecies is one "whose impacts on its community are large, and much larger thanwould be expected fromitsabundance" (Power andMills 1995: 184). An attempt to quantify this effectas an index of com- munityimportance or CI (Power et al 1996) gives too littleaccountof thresholdand othernon-lineareffectsto provide aneffectivebasis for identifyingkeystones. Combining its qualitative aspect with the functional redundancyrequirement(Schulze and Mooney 1994: 502)salvages both to produce aworkable functional definitionof an ecological keystonespecies (cf. Kotliar 2000), whichwe can thenextendto include ecosystem elementsof other types. We thus definean ecological keystone as anyfunctionallyuniqueecosystemcomponent whose removalwould lead to a structural simplification disproportionate withits abundance. Cultural Keystones Many human populations inhabit ecosystems in whichtheir ecological roleis thatofa keystonespecies, andcan thusbe designated"keystone societies" (Meilleur1994; also see Kay 1998; O'Neill and Kahn 2000). In recent years, the keystoneconcept has been applied to humanformationsto describe the cultural importance of certain biological } Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and ConditionsHumEcol (2009) 37:491-500 493 frommorefamiliar concepts. The suspicion in bothcases is that anynovelty is more terminological than conceptual. Ellen (2006) notes the similarity of these approaches to his earlierintroductionof the term "ethnobiological keystonespecies", definedas "organisms that by virtueof theirusefulnessto humans may become ecologically crucial to themaintenanceof entire anthropogenicenvironments, subsistence systems and ways of life" (Ellen 2006: 259). Ellen's majorexample is use of the sago palm(Metroxylon sagu) by Nuaulu in Seram, for whom its nutritional importance and range of otheruses have far-reaching consequences for land use and social relations (Ellen 1978, 2004a, b, 2006). Definingkeystones in relationto the structureand dynamics of social-ecologicalsystems is consistentwiththe use of the concept in ecology, but in the sago case is restrictedto a single level of system organisation.However, like those it anticipates, Ellen's approach assumes a cultural keystone to be equivalent to a singlebiologicalspecies, whichwe believelimitsthe value of the keystoneconcept for understanding cultural formations. We assertthata cultural keystone is not a biological speciesperse, buta complex.Although oftencentred upon a particularspecies, acultural keystonecomplex also includesnumerousother systemelements, both material andnon-material (Platten2005; Henfrey and Platten 2006). Brosi et al (2007) identify at least 27 species of plants involvedin canoe constructionin Pohnpei, Micronesia. Theircharacterisationof this activity as a cultural keystone practiceemphasises, in our assessment, how cultural keystonecomplexes combine biological species, knowl- edge, and technical practice. We proposedefining cultural keystones, like ecological keystones andliteral keystones,according to theirstructural roles, withinsocial systems. We thusdefinecultural key- stones as system elementswith crucial non-redundant functionsin maintainingany particular level of structural complexity. The following sectionselaborate upon this definitionwithreferenceto ethnographic datafromourown researchon subsistence practices of Wapishanapeople in Southern Guyana conducted during1998, 1999 and 2000 (Henfrey2002), and marketcultivationin the Minahasan village of Rurukan, North Sulawesi,during2000, 2001 and 2002 (Platten2005). In eachofthese societies, we identify a cultural keystone based arounda single species of cultivated plant. For Wapishanapeople, thecultivationand use of bittercassava is centralto the subsistence economy and household integration into broadersocial networks.Its structuring effectson social relationships are diverse; its importance thusextendsfar beyond itsmaterialcontributionto the diet, which exemplifies the systemicproperties we treatas definitiveof cultural keystones. In Rurukan, carrotsare the main cash crop, and part of a cultural keystone at a differentlevel of systemorganisation: that of village integration into regional markets.Its place in the market domain distinguishes it in importantways from the Wapishanaexample and othercultural "keystonespecies" previously identifiedin the literature, and demandsmore detailedelaboration. Cassava as a Cultural Keystone forthe Wapishana For GuyaneseWapishana, as for many otherAmerindian groups of lowland tropical South America, bittercassava (Manihotesculenta) is centralto the diet and subsistence strategy(Henfrey 2002: 84-93). Not only is it the most importantcrop, in termsof allocationof land,agricultural labour, and calorific contribution, its effectson matterand informationflowsextendfar beyond thismaterialcontribu- tion.Its consumption and use, and the complex of values and practice thatsurround them,strongly affectsubsistence strategies, social organisation, seasonal and daily activity schedules, and perceptions of identity and wellbeing. This pervasive influenceon practices to which it is only indirectly relatedmakes the bittercassava complex the majorstructuring elementin Wapishanasociety at thelevel ofdomestic reproduction, andfitsourdefinitionofa cultural keystone.Although not strictly essentialfor survival, in that itsnutritionalrolecould conceivably be replacedbyany ofa numberof other starchycultivars, it is essentialto the maintenanceand reproduction of society in its present form. As has been observedin a numberof otherlowland Amazonian groups,(e.g., Mentore 1983-1984; Riviere 1987; Heckler 2004), many featuresof Wapishana material culture and social life reflectthe unique processing demandsand culinaryproperties of bittercassava. The extensivetoolkitinvolvedin cassava processingcomprises the most important material possessions of a typical Wapishanafamily. The constanttasksof peeling,grating, squeezing and cooking cassava roots are the major determinantof femaletimeallocationand also provide an important forumforsocial interaction among womenand verticaland oblique transmissionof knowledge. Unique qualities of cassava products determinehow Wapishana men provision themselvesforextended stays away fromhomeon hunting and fishingexpeditions. A bag of farine - a coarse cassava meal - and jar of casareep, a treacly condimentmade byboiling downcassavawaterand used to flavour soups and stews - are the only foods normallycarried,supplemented withhot peppersgrown at huntingcamps, andeatenwith game and fish procured over thecourseof the expedition. Cassava also plays a key social role as thebasis forthe preferred alcoholic drinks,notablyparakari, a thickbeer ) Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and Conditions494Hum Ecol (2009) 37:491-500 householdswithoutmeansof irrigation. Cultivationin lower elevationfieldsthus supportsvegetableproduction at higher altitudes. Among Rurukan villagers, carrots consistently achieve high scores in free listingexercises, and are the default topic of conversationsabout agriculture: if no particular crop is specified,participantsgenerally assume they are talking aboutthem.This high culturalsaliencereflectsa keystone role thatderives from, but greatlytranscends, theireconomic importance. Collective organisation for carrot production in Rurukan,along with villagespecial- isation in general, can beunderstoodas expressions of an egalitarian culturalmodel characteristicof the Minahasan heartlandthat places value on cooperation and reciprocal aid (Platten2005, 2007). A Minahasan phrase which may be translated as, "A person livesto give lifeto others",accuratelyexpresses thecombinationof an emphasisupon sharing and the celebrationof individual advancementthatis at the heartof the region's moral economy. Carrotcultivationis an appropriate vehiclefor expres- sion of this model, and conforms particularly well to the Minahasan self-image. A single harvest generatesonly a modestincome:the real financialbenefitsaccrue from multiple annual harvests,requiringcooperationamong a community of specialised workers includingcultivators, harvesters,wholesalers, truckdriversand markettraders. Labour is organisedthroughmapalus - reciprocal and waged work groups - in order to prepare the ground, constructraised beds,weed,harvest,process, and transport thecarrotsfromthefields. Consequently, carrot productionprovidesmanyoppor- tunitiesfor collective labour, which along with role specialisation fosters interdependence withinthe village. Success at this interfacebetween moral and market economies promotes individualwealthand at the same time is commensuratewith creatingstronginterpersonal bonds. Villagersemploygossip, rumouranddirect sabotage against those suspected of selfishlyhoardingprofits while skimping on theircontributionsto theconditionsandwealth of the community as a whole.Thesetactics simultaneously encourage innovationand conformity, and promote collective actionwithinthe village. Carrot cultivationalso plays acentralrole in the transmissionof cultural knowledge, both specific to agriculture and of widerrelevance.Technical knowledge specific to carrotcultivationincludesthe constructionof raised beds, and particularregimes of sowing,thinning, weeding, harvesting and processing. Collective work groups are the communitiesof practice withinwhich membersof the youngergeneration learn to become cultivators, as well as themainsourceof incomefor young adultsand newly formedhouseholds. made from mashed, fermentedcassava roots.Parakarior othercassava-baseddrinksare crucialnot only to a good party, butalso in collectivework arrangementsupon which most people depend for accomplishing labour-intensive tasks. One extended family whose religious affiliation obliges themto be teetotal, is not only excludedfromthese work groups butalso sociallyisolated, others commenting that,"they don'tdrink parakari likeus". Althoughmateriallysubstirutable, bittercassava is thus culturallyirreplaceable intothe Wapishana.Duringdrought- induced cassava shortages in 1998, even people with adequatesupplies of other starchy foods regarded thelack of cassava as a severe hardship. Whilea Wapishanafamily could, in theory, subsistwithoutcassava and its products, it would by doing so find itself socially marginalised or excludedin several respects,many ofwhichhave important economicfunctions.These includecollective agricultural and domestic labour, communal eating on hunting and fishingexpeditions, and many othersnot describedhere such as germplasmexchange and celebratorydrinking parties or feasts.These structural influences,affecting such a range of socialand cultural aspects of subsistence beyond itsdirectmaterial importance, makethecultivationand use ofbittercassavaa cultural keystone. Carrotsas a Cultural Keystone in Rurukan, Minahasa In highland areas of the Minahasa region of North Sulawesi, Indonesia, the predominantactivity is market gardening of vegetables. Most villagesoccupy a particular market niche,specialising in the production of a single crop. In the 1980s, cultivatorsin the village of Rurukan began to specialise in thecommercialcultivationof carrots (Daucus carota). Rurukannow dependsupon thesale and cultivationof carrotsforbothliteraland symbolicpartic- ipation in regional networksof commercial exchangeand, by extension, fortheassertionof identity and statuswithin the regional market system. Plot surveys in Rurukanfieldsindicatedcarrotsto be the dominant crop. Several other vegetables are extremely common,including maize {Zea mays),bunching onions {Alliumfistulosum), andvariousbrassicas (Brassicachinesis, Brassica pekinensis, Brassica oleracea), each of whichin some way supports carrotcultivation.The brassicassoften the soil prior to plantingcarrots;bunching onionsservea similar purpose, or can be interplanted withcarrotsand sold piecemeal,providing a subsidiary incomebetweencarrot harvests. Maize, intercropped with carrots,protects the plot fromdraftanimals.It is also planted as a cash crop in lower elevationfieldswherecarrotsareless productive,along with cloves, which supplement householdincome throughout the year and are the sole dry season incomesourcefor ) Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and ConditionsHum Ecol (2009) 37:491-500495 Carrotsalso play a centralrole in thecombinedharvest festivaland foundinganniversary celebrationsin the village's Protestantchurch.The climax of the festivities involves placing carrotson a tablebeforethe pulpitduring an elaborate pujian (act of praise). Significantly, unlike other crops suchas rice, thereareno referencesto guardian spirits of carrots. They are incorporated intothe harvest festivalas symbolic of the agriculturalsystem and the collectiveactionsofthe community, ratherthanas an object of religiousworship in themselves. Whilecarrotsare therefore integral to Rurukan identity, theyrepresent ratherthansubstituteforthat identity. Thatis to say, while carrotsthemselvesdo not appear in any Rurukan iconography, theircultivationand sale are socially symbolic vis-a-visother villages.Theyprovide the village not only with asource of income, but with culturally appropriateidentity and statuswithintheMinahasa Region. Other villages, fortheir part,occupysimilarlyspecialised economic niches. They thus exercise their keystone functionat thelevelof villageintegration intothis regional system. awide range of game animals,fish, various gathered animalssuch as tortoise (mainly Geochelone denticulata), and domesticlivestock. A type of natural experiment arises fromits patchy distributionin space and time, whichmeans it may be absent fromcertainareas of foreston a temporary or permanent basis. When forseveral years no white-jawed peccaries werefoundin the huntinggrounds of the study village, no dramatic changes ensued, althoughpeople lamentedtheirabsence and charged theirmost powerful shamanswith bringing about theirreturn.In some other villages, whose residents relypredominantly on fishand domesticlivestockforanimal protein and where hunting is relativelyunimportant, most people consider white-lipped peccaries not as prized game, but a dangerous and voracious croppest. Developing the Cultural KeystonesConcept Each of the foregoingexamples in some way illustrates how ouruse of the concept of thecultural keystone differs fromthatof earlierauthors (Ellen 2006; Cristanchoand Vining2004; Garibaldiand Turner 2004a, b), in three related ways. Aside from Ellen, they do not adequately distinguish between keystones as system elementswith well-definedfunctional characteristics, and speciesimpor- tantin other ways. All referto cultural keystonespecies, whereasthe cultural keystone is in facta complex, often based aroundone or more biologicalspecies but incorpo- rating several further elements, both materialand non- material.Allalso relate largely to subsistence-based, economically bounded systems, and do not address key- stone functions relating to participation in supralocal networksof commercial exchange. The Tayassupecari example helps to illustratehow involvementin cultural keystones differsfromotherforms of cultural importance. For the Wapishana, bich would score high on all ratings of cultural importance.Despite this, neitherits absence, nordeclinein its exploitation has any wider social or culturaleffects.Failure to hunt peccaries and eat theirmeatwould appearfairlypeculiar, but have no deeperconsequences. In contrast, not to use cassava would imply exclusionfromalmostall aspects of social lifeand effective non-participation in thesubsistence economy. BothGaribaldiand Turner (2004a) and Christanchoand Vining(2004) proposetypologies, or listsof characteristics that identify candidatesfor cultural keystonespecies. Neither providesany reliablemeansof distinguishing cases suchas cassava, whichis an important elementin a cultural keystone, from peccary, whichis not.In theRurukan case, thesameis truefor carrots, thecentreof a cultural keystone White-JawedPeccaries: CulturallySignificant, but not Part of a KeystoneComplex Another example fromthe Wapishana demonstratesthe differencebetweencultural keystones and species which, althoughculturallyimportant, are not implicated in any keystone functions.The white-jawedpeccary,{Tayassu pecari), whose Wapishana nameis bich, is themostsalient and popular game animal for Wapishana subsistence hunters.Informationon sightings of bich herds and discussionof their possible movementsare themain topic of conversation among hunters.In freelistsof Wapishana animal names, bichwas almost alwaysfirst, and inevitably among thefirsttwoor threenamesmentioned. Interviewswithhunters suggested kill ratesforbich to be among the highest for allhunted mammals, and opportunities to huntthemtake priority over any other task. Huntingstrategy and symbolicregulation of resource use may, to some extent, be adapted to the behaviourof white-jawedpeccary herds, which range overvastdistances. Its symbolic treatmentdiffersfromthatof otheranimalsin encouraging, ratherthan deterring,hunting toexcess (Henfrey 2002: 101-108). Despite its importance, we do not consider Tayassu pecari to be part of any cultural keystonecomplexamong the Wapishana. If it did not exist, therewould be no significant effects uponhunting behaviourandother aspects of cultureand societybeyond those specifically concerned withitsuse. Its dietary contributionis farfromexclusive: thereare many otheravailablesourcesof protein,including ^Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and Conditions496HumEcol (2009) 37:491-500 fromthe cultural keystone in its specific referenceto cultural adaptations to the ecologicalsetting. As a result, it embodiesa seriesof implicit,unacknowledgedassumptions concerning "culture" (Ellen 1982: 52-65). We, in contrast, simply assume cultureto be a featureof any system in which humans play a part. The exact definitionor characterisationof cultureis unimportant to the present argument. We have defineda cultural keystonecomplex in termsof its structuralor organisational role withinsuch culturalor culture-bearingsystems, without preconceived assumptions as to ecological or otherfunction. The incorporation of subjective factorsintothecultural keystonesconcept also highlights amore important implication of our analysis. The keystone statusof any species is neitherinherentnor inevitable:it is culturally ascribed, and this contingently. Rurukan's specialisation in carrotcultivationis a relatively recent development.During the late nineteenthand early twentieth century the village was renownedforits production of palmsugar; eitherside of Japaneseoccupation in the mid-twentieth century the village was knownforthe quality of its maize. Thus in Rurukan, it is not the details of the cultural keystone complex - carrots being substitutable - but its very exis- tenceto whichwe ascribe adaptivefunctionality.Neigh- bouringvillages have similar complexes centredon other cultivars, or evenon non-agricultural economicactivities.It is notthe biologicalspecies involvedthatis crucialto the status,identity, and economic security of the village within the wider regional system, but the cultural keystone complex of whichit is a part. In both cases, organising economic production on a keystonepatternappears to reflecta consciouschoice.This is obviousin thecase of Rurukan, in whichthedecisionto specialise in carrot production was sufficiently recentto allow its documentation.The origins of the Wapishana obsessionwithcassavaare more historically obscure.How- ever, itis only one of many sourcesof complexcarbohydrate grownbyWapishanacultivators, whichraisesthe question of why a single food plant has been assigned suchan exalted role.It seemsthatinthiscase too, an economicallyimportant plantspecies hasbecomethecentreofa cultural keystone via a conscious process ofsocial engineering. This observation anticipates ideas within ecological engineering on the potential relevanceof the keystone model to social change. The widespreadimportance of keystones in ecologicalsystems is testimony to theeffec- tivenessof a keystone structureas a strategy in engineering design (Rosemund and Anderson 2003). This strongly suggests that keystones will also be commonin social formations (Lawton and Jones1995: 147). In ecological management, ithas been suggested thata focuson keystone speciesmay be an effectivemeansof articulating between complex, and rice. Although it scores highly on all measuresof cultural importance, ricehas no keystone role (Platten2005). No approach of this type, based on listsof features, can be usefullydiagnostic of cultural keystones, whichin the absenceof a formal systems model can be identified only in referenceto contingent featuresof any particular case.Just as ecological importance isnot equivalent to being an ecological keystone(Hurlbert 1997), cultural importance is not sufficientto identify a cultural keystonecomplex. Cultural Keystones as Complexes A furtherlimitationof theuse of listsof diagnostic features is thatthese apply to singlebiologicalspecies. We believe thisto perpetuate a crucialerrorin previousapproaches, an assumption thatcultural keystones will equate with biolog- ical species. Both of the examplespresented here are of cultural keystones based around singleplantspecies. The temptation to use this species as a signifier forthe wider complex is compelling - a singlespeciesis, indeed,"good to think" - but implies a reductionismthatunderminesthe utility of the concept. Formulating the cultural keystoneconcept in systemic termsdemandsthatit refernot to biologicalspecies, but to complexes of interconnectedmaterialand subjective factors.The social and cultural importance of Manihot esculentafor the Wapishanadepend on the knowledge, practices andtoolsinvolvedin itscultivationand use,along withseveralwildor semi-domesticated species thatin some way support these. Similarly, in the Rurukan agricultural system the keystone is notDaucus carota, but a complex based aroundits cultivationand sale. The lower field maize-clove association,mapalus work groups,system of land tenure, local egalitarianethics, andthe centrality ofthe churchwithinthe community, areall essentialto theroleof the carrotcultivation complex in maintaining the cultural identity and practice withwhichit is consubstantial.The reproduction of Rurukanas a community with distinct identity, roleand statuswithinthe regionalsystemdepends upon the keystone functionof this complex, whichcarrots alone couldnotfulfil. Extending the cultural keystone froma conceptually securebut analyticallyunproductive notionof equivalence with a biologicalspecies createsa superficialsimilarity withJulianSteward'scultural core, "the constellationof featureswhich are most closely relatedto subsistence activitiesand economic arrangements...(including) ...such social, political, and religiouspatterns as are empirically determinedto be closely connectedwith these arrange- ments" (Steward 1955: 37). However, thisdiffers crucially ) Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and ConditionsHumEcol (2009) 37:491-500497 species-focused and system or landscape approaches (Simberloff1998). Attempts to baseconservationof Amazonianforests upon the commercialextractionof Brazil nuts (Bertholletiaexcelsa) show how flagship strategies based arounda keystonemay assistthe recon- ciliationof ecological,social, and economic aspects of resourceconservation (Clay 1997). Such initiativesamount to self-consciouslychoosing a cultural keystone - sometimes centred upon an ecologicalkeystone - asa strategy for action, and appear to replicate an approach chosen in Rurukanin livingmemory, and among the Wapishana or theirancestorsin times prior to theirrecorded history. cultural keystone limitsthe range of culturallyappropriate formsof social action, and thus simplifies social decision making on the part of individual producers. The benefitsareclearestin theMinahasan case, in which it is easy to imagine alternative ways of organising involvementin the regional market economy.Basing market production arounda keystonecomplex not only reflects underlying cultural values, but has manystrategic advantages. At alocal level, specialisation allows for collective organisation of labourand sales, avoids compe- titionwithother villages, and promotes the development of a greaterdepth of task-specific skills.At a regionallevel, production is diverse, comprising numerousdifferent villagespecialisations, in each of whichtechnical capacity is higher than asimilar numberof more generalist strategists would provide. It is clearfromthese descriptions thatwe regard cultural keystones as conservativeelementsof social systems. The advantages of providing stablesocial formations, and fixed reference points forindividual decision-making, are clear, but dependupon other parts of the systembeing flexible and responsive to changing conditions.Theircontribution to the necessary balance between rigour and imagination (Bateson 1979: 191-197, 204-219), means thatcultural keystonesby their stability, enable such dynamism else- wherein the system.However, it is clear that any such intransigent, dominant system elementcould prove mal- adaptive in thefaceof rapid external change if it limitsthe overall capacity to adapt. This has happened on severaloccasions in the recent history of Rurukan, which has seen several changes in the identity of the dominantmarket crop. This has necessitated profoundchange in systems of market cultivationand sale: the cultural keystonecomplex has had to be rebuilton every such occasion. The global economycurrently faces a similarsituationin the form of "carbon lock-in" (Unruh2000)- a set of interlinked social, technical and economic factors that remains stubbornly resistantto change, and greatlyhampers attempts to reduce global dependence on fossil fuel consumption. As the cultural keystoneconceptdevelops in sophistication, it may well contributeto improved understanding of such situations, and provide useful suggestions towardstheirresolution. Defining a cultural keystone as an elementthat supports some level or otherof systemcomplexitysuggestssteps towardsa morerobust operational definition.The use of ecological modelsis a promisingtechnique forthe non- experimental identificationof ecologicalkeystones, whose totalinteractionswithother species in the ecosystem are disproportionatelystrong(Tanner et al 1994). A similar approach, based on formalmodels of informationflows Cultural Keystones and System Structure The role of carrotsin acultural keystonecomplex in Rurukanderivesnot fromsubsistence use, but fromtheir statusas themost important commercialcultivar.Cristancho and Vining(2004) give no examples of cultural keystone species so entrenchedin the market domain, nor criteria significantly relatedto the degree of commercialisationof the species concerned.Such analyses would mostlylikely considercultivationformarketsale as a single use. However, thefinancialremunerationcan be utilisedtowardsnumerous ends, notall ofwhichare immediately economicin a formal sense, and in some circumstancesthe major commercial activitymay be thecultural keystone. Thisis not always the case: among the Wapishana, the only cash crop of any notable importance is peanuts, which manypeoplegrow to raisea modestincome. However, this crop, andtheincomeit provides, is of secondaryimportancecompared to sub- sistence production, andfarmers alwaysgivepriority to their cassava farms.This reflectsafurtherweaknessof such generalisinganalyses: the characteristicsof acultural keystonemay differ strongly fromone situationto another. Analyses biasedtowards conceptually bounded societies, economically self-sufficientin termsof subsistence produc- tion, tendto ignore the possibility of cultural keystones operating at the level of market integration, and the consequences ofthese very differentcircumstances.Market productionimplies involvementin widersocial networks beyond the group forwhichthe keystone is identified.In Rurukan, carrot production functionsas a cultural keystone at the level of thesewider networks, and because of its importance in the marketinteractions upon whichthese networksare based,being essentialfor communityrepro- ductionwithinthecontextof a regionalsystem of market exchange. Forthe Wapishana, cassava consumption anduse exerts its keystone role at alower level of system complexity, thatof domestic reproduction withina largely village-basedsubsistenceeconomv.In both cases, the ) Springer This content downloaded from 130.238.7.43 on Wed, 5 Nov 2014 09:25:24 AMAll use subject to JSTOR Terms and Conditions498Hum Ecol (2009) 37:491-500 the value of the concept as atool for interdisciplinary communication. However, the absence in most cases of critical engagement raisesthe danger of reducing itto little more thana catchphrase, aroundwhichinteractionscan neverbe morethan superficial. A more thoroughworking out of the meaning,significance,potential and limitations of the cultural keystoneconceptmay,ironically,hamper such communication,by eliminating the verysimplicity that, like thatwhicha cultural keystonebrings to social integration, bothfacilitatesit and limitsits depth. Thiswill ultimately be worthwhile if, by providing a concept of genuinely distinctive analyticalvalue, it encourages more meaningful communication among the diverse fields relevantto the protection of biological and cultural diversity,leading to a deeper mutual understanding and greatercapacity for productiveengagement. Acknowledgements Thanksto Roy Ellen and Michael Fischerfor instructiveadvice and comments during the writing of this paper, to Rachel Kaleta for introducing us to the keystoneconcept, to our friendsin each of the research locations, and to two anonymous reviewers.Simon Platten's fieldworkwas supportedby an ESRC- NERC studentship. Thomas Henfrey was supportedduring fieldwork by an APFT studentship fromEC DG VIII, and duringwritingby a Hunt postdoctoralfellowship fromthe WennerGrenFoundation. withinsocial systems,may well provide a practical method to identify cultural keystones, as well as more precise characterisationof their systemicproperties. Conclusion:The Importance of the Cultural Keystone Concept In summary, cultural keystones are complexes ofbeliefand practice with non-redundantfunctionscrucial to social reproduction at any organisational scale withina sociocul- tural system.Although most documented examples are based upon one or a smallnumberof biologicalspecies, it is not technicallynecessary thatthis be the case. Most importantly, acultural keystone is in no case directly equivalent to a biologicalspecies. Even if based arounda single species, a cultural keystone is a complex, whose contributionto system structurealso dependsupon a range of other factors,including other biologicalspecies, arte- facts,knowledge, and social practices. More importantly, it also dependsupon a range of purelysubjective factors: beliefs,ideas, normsand values concerning social identity and itsenactment throughculturallyappropriatepractices. Extending thecultural keystonesconcept froma species to a complex leads to furtherobservations. First, the inherent,objective featuresof the species involveddo not determinethat they willbe part of a cultural keystone: such roles are culturallyprescribed,although it is entirely possible thatsome species are bettersuitedto this than others. Second, the detailed featuresof the cultural keystonecomplex are less important thanthe factof its existence.A keystonearrangement forsocial integration is a functionally sound one, on which numerousdifferent societies have converged. Our analysis suggests that societies have, in effect, "chosen"to organise arounda keystonemodel, and this has shaped the way in which particulareconomicallyimportantspecies are used and not thereverse. In both examples of cultural keystones described here, the major materialelementis potentially substitutable.In Rurukanand otherMinahasan villages, market specialisa- tion in a singlecrop is a mechanismforeconomicand symbolicintegration ofthe village intoa regionalsystem of commercial exchange(Platten2005, 2007), and a locus of articulationbetweenindividual producers and thisbroader system(Henfrey and Platten 2006). For the Wapishana the dominanceof cassava as a staple facilitatessocial integra- tionat thelevel of thedomestic economy. The majorimpact to date of previous treatmentsof the cultural keystone concept has been their uptake by researchersin conservation biology(e.g., Byg et al 2006; Brosiet al 2007; Gelcichet al 2006; The Snow Leopard Conservancy2007; Ticktinet al 2006). This demonstrates References Bateson, G. (1979). Mind and Nature:A NecessaryUnity.Fontana, London. Bond, W. J. (1994). Keystonespecies. In Shultze, E. D., and Mooney, H.A. 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