w ww . e l s e v i e r . c o m / l o c a t e / b j p
Original
Article
The
use
of
different
indicators
for
interpreting
the
local
knowledge
loss
on
medical
plants
Camilla
de
Carvalho
de
Brito
a,
Taline
Cristina
da
Silva
b,
Ulysses
Paulino
Albuquerque
b,
Marcelo
Alves
Ramos
c,
Washington
Soares
Ferreira
Júnior
d,
Fernanda
Novais
Barros
a,
Eraldo
Medeiros
Costa
Neto
e,
Patrícia
Muniz
de
Medeiros
a,f,∗aProgramadePós-graduac¸ãoemCiênciasAmbientais,UniversidadeFederaldoOestedaBahia,Barreiras,BA,Brazil bDepartamentodeBiologia,UniversidadeFederalRuraldePernambuco,Recife,PE,Brazil
cCampusMataNorte,UniversidadedePernambuco,Centro,NazarédaMata,PE,Brazil dCampusPetrolina,UniversidadedePernambuco,Petrolina,PE,Brazil
eDepartamentodeCiênciasBiológicas,UniversidadeEstadualdeFeiradeSantana,FeiradeSantana,BA,Brazil fCentrodeCiênciasAgrárias,UniversidadeFederaldeAlagoas,RioLargo,AL,Brazil
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received2May2016 Accepted11September2016 Availableonline24November2016
Keywords:
Localknowledge Erosion
Traditionalbotanicalknowledge Ethnobotany
a
b
s
t
r
a
c
t
Theincreasing lossoflocal ecological knowledgemay havenegativeimpacts ontheresilience of socio-ecologicalsystemsandmayalsonegativelyimpactbioprospectingefforts,sincelocalecological knowledgeisanimportantsourceofinformationforsearchingnewdrugs.Recentstudiestryto evalu-atewhethercommunitiesareexperiencinglossoflocalecologicalknowledge.However,someofthem makeconclusionswhichareerroneouslybasedonspecificanalysesofasingleindicator.Wepropose anintegrativeanalysisofthreeindicators,namely:numberofplantscitedbyyoungpeopleandelders, therapeuticchoicesandpeople’sconnectanceintermsofmedicinalplantlearning.Thestudywas car-riedoutinthecommunityofSucruiuzinho(Bahia,Brazil).Weconductedsemistructuredinterviewsand atherapeuticrecallwith24localdwellers.Wedidnotfindevidenceoflocalecologicalknowledgelossin thestudiedcommunity.Althoughyoungerpeopleknowfewerplants,theyarewellconnectedintermsof knowledgetransmission.Moreover,inillnessevents,youngpeopleandadultshavesimilarproportions ofchoiceforplantswhencomparedtoallopathy.Concomitantuseofthethreeindicatorsleadstoamore realisticscenariooflocalecologicalknowledgelossthantheuseofonlyoneofthem.
©2016PublishedbyElsevierEditoraLtda.onbehalfofSociedadeBrasileiradeFarmacognosia.Thisis anopenaccessarticleundertheCCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/ 4.0/).
Introduction
It hasbeen arguedthat local populations around theworld
arelosing theirlocalecologicalknowledge(LEK), and this phe-nomenonprimarilyaffectsyoungpeople’sgenerations(Benzetal., 2000; Voeks and Leony, 2004; Reyes-Garcíaet al., 2013). Sev-eralfactorsappeartoaccountforthischange,suchas:decrease in biological and cultural diversity (Malthez-Stifel et al., 2012; Sujarwoet al.,2014), modernization (Quilanand Quilan,2007),
urbanization(Teklehaymanotetal.,2007),economicdevelopment
(Reyes-Garcíaetal.,2005)andlanguagebarriers(Benzetal.,2000; Zent,2001).However,thevastmajorityofworksusuallyevaluates
∗ Correspondingauthor.
E-mail:patricia.medeiros@ceca.ufal.br(P.M.Medeiros).
indirectlytheprocessesofknowledgeloss,regardlessofthecurrent standardsofintraculturalvariability(Zent,2001).
Severalauthors suggestthat young people’sgenerations are
undergoingaprocessofknowledgeloss,fromaconclusionbasedon asingleindicator:thenumberofplantspeciesknownbytheyoung
peoplecomparedtothenumberofspeciesknownbyolderpeople.
However,analternativeinterpretationofthisfindingisthatyoung peopleknowlessplantsbecausetheyarestillinthelearning pro-cess(VoeksandLeony,2004;Albuquerque,2006;Silvaetal.,2011; Malthez-Stifeletal.,2012).Thus,ananalysisguidedonlyinthe
amountofknownplantspeciesdoesnotallowrobustinferences
abouttheprocessoftheknowledgeloss.
Anotherindicatorthathasbeenemployedtoanalyzetheloss
ofLEKonmedicinalplantsisrelatedtotherapeuticchoices
cen-teredonthedichotomyallopathicmedicines×medicinalplants.
Researcherssuggestthataccesstomodernmedicinescanleadto
disinterestofpeopleinlearningaboutmedicinalplants oftheir
http://dx.doi.org/10.1016/j.bjp.2016.09.006
Consideringthescenariopresentedabove,thatreinforcethata simplisticassessmentofthelossoflocalecologicalknowledgecan
bringinadequateconclusionsaboutacomplexphenomenon,this
studyintegratesasetofthreeindicatorstoassessthelossofLEK
onmedicinalplants:numberofplantsmentionedamongyoung
peopleand elders; therapeutic choices (allopathic ormedicinal
plants)andyoungpeople’sconnectanceintermsofmedicinalplant learning.Ourthirdindicator(connectance)isimportantbecause
itshowshowindividualsareexchangingmedicinalplant
knowl-edge. In this sense,the best of ourknowledge, theuse of this
toolhasnotbeenpopularamongstudiesaboutlossofLEK,and
hasnotbeenusedtogetherwiththeotherindicatorsmentioned
above.Connectancecalculationsarecommon,forexample,in eco-logicalstudiesaboutfoodwebpatterns(Kondoh,2013).Theyare
alsopresent instudies that usetheconceptof social networks
(Haselmairetal.,2014).Althoughtheideaofsocialnetworksis beingincreasinglyusedinethnobiologicalresearch,itisnotour aimtodeepentheoreticalaspectsonthesubject,but,instead,to usea tool thatis alsoemployedin suchstudies.Suchtool will revealifpeopleareexchangingknowledgeoriftherearebarriers
compromisingsuchtransmission.
Thisresearchproposalaimstofilltheoreticaland methodologi-calgapswithregardtotheproposalofthreeindicatorsthatcanbe decisiveforthedetectionoflossofLEK(numberofknownspecies,
therapeuticchoicesandconnectanceintermsofmedicinalplant
learning).Therefore,itcanbeusefulinfutureresearchesaimedat
documentingthisphenomenonmoreaccurately.
MakinganaccurateevaluationofLEKlossisimportantsince
such knowledge commonly increases the resilience of
socio-ecologicalsystems(FerreiraJúnioretal.,2015).Furthermore,the
increasinglossoflocalecologicalknowledgemayhavenegative
impactsonbioprospectingefforts,sinceLEKisanimportantsource ofinformationforsearchingnewdrugs(Heinrich,2008).
Materialsandmethods
Studyarea
We tested ourproposal in the community of Sucruiuzinho,
placedinthemunicipalityofBarreiras,stateofBahia, Northeast-ernBrazil(Fig.1).Itislocated20kmfromthecenterofBarreiras. Barreirasis905kmfarfromBahia’scapital,Salvador(IBGE,2010). Themunicipalityhasanextensionof7859.225km2andaltitudeof 452m,withanestimatedpopulationof150,896inhabitants,13,686 oftheminruralareas(IBGE,2010).Thecityischaracterizedbyits averageannualtemperatureof24.3◦Cwithaverageannualrainfalls
varyingfrom1100mmto1200mm(SEI,2007).
Sucruiuzinhohastwentyhouseholdsand37residents(21male
and16female).Thecommunityisplacedinaruralareaandhas
nohealthcenters,schoolsorbasicsanitation.Thenearesthealth centerislocatedinthecenterofBarreiras.However,thecommunity residentsreceivevisitsfromadoctoreachthreemonthsaswellas monthlyvisitsofthelocalhealthagents.
Datacollection
Theinitialcontactwithcommunitymemberswasperformed
withtheassistanceofamemberoftheneighboringcommunity
(Sucruiu),whichparticipatedinpreviousstudiesdevelopedbyour
committeeinresearchwithhumanbeingsthroughthePlataforma
Brasil(CAAE07488513.4.0000.5026).
Duringthefollowingvisits,weconducted24semi-structured
interviews(Albuquerqueetal.,2014).Ourstudydesignincluded
peoplewithpermanentresidenceinthecommunityandover10
years.Therefore,24peoplefrom14to83years-oldparticipated, consideringthattheintervalbetween10and13yearswasnot rep-resentedinthecommunity.Notallresidentsparticipated inthe
survey,astwopeoplerefused;sixwerenotold enoughto
par-ticipate,andfivewerenotfoundevenafterseveralattempts.We choseasmallcommunity,sinceitfacilitatesconnectanceanalysis ofmedicinalplantlearningwhichwillbedescribedbelow. There-fore,weinterviewedatotalof63%oftheresidents(77%ofthoseold enoughtoparticipate)inordertoidentifywhichmedicinalplants
areknown (indicator1),besidescollectingsocioeconomicdata.
Afterthisstep,thetherapeuticrecallwasperformed.Wenamed
“therapeuticrecall”theadjustmentoftherecall24hcommonly
usedin ethnobiologicalstudies(Albuquerque etal., 2014).This techniqueaimedatanalyzing:(a)Theself-reportedillnessevents sufferedbytheintervieweeinthelastyear;(b)andforeachillness event,iftherespondentmadeuseofallopathyormedicinalplants. Thismethodologicalstepgenerateddatathathasbeenanalyzedas theindicator2ofknowledgelossbetweengenerations,asitwas relatedtotherapeuticchoices.
Afterwards,inordertoanalyzehowconnectedaretheyoungers
tothecommunityin termsofmedicinalplantlearning
(indica-tor3),alistwiththenamesofallpeopleinthecommunitywas
presentedtotherespondents.Theywereinvitedtoindicatethe
individualsinthelistfromwhomtheyhavelearntabout medici-nalplants,aswellasthoseindividualstowhomtheyhaveactively taught.Thismethodologicalprocedurecarriesariskofbias,since theteachingandlearningeventswereallbasedontheinformant’s memory.Thus,wetriedtoreducethismethodologicalbiasas fol-lows:whentherespondentxclaimedtohavelearnedaboutplants
froma respondentyandrespondentydidnotmentiontohave
transmittedknowledgetotherespondentx,theinformationabout
thetransmissionofknowledgefromxtoywasconsidered,thus
increasingthereliabilityoftheinformation.
Dataanalysis
Toanalyzethefirstindicatorofknowledgelossbetween gener-ations,weusedasimplelinearregressiontoassesstherelationship
betweenageandnumberofknownplants.Thesedatawere
sub-jectedtoasquareroottransformationtofitinanormaldistribution.
Thenweperformedasimilaranalysisconsideringtheknowledge
onplantsofpeopleupto50yearsold(12peopleintotal),sincewe observedaposterioriastabilityinplantknowledgeofpeoplefrom thatagegroup.
Thecitationsfordifferenttherapeuticchoices(allopathic,plants andboth)wheninformantsfacedhealthproblems,oursecond indi-cator,werecomparedbetweenageclassesthroughFisherExtract.
Threeagegroupswereconsidered:class a(between 14and 36
years)(sixpeople),classb(between37and59years)(eightpeople) andclassc(between60and83years)(tenpeople).Moreageclasses
werenotadoptedinthisstudybecauseofthelimitednumberof
peopleinthecommunity,whatwouldleadtoclasseswithsmall
B R A Z I L
B a r r e i r a s
B A R R E I R A S
B A H I A
W E S T E R N
R E G I O N
W e s t e r n r e g i o n
U r b a n a r e a S u c r u i u z i n h o
B a h i a
0 550 1100 2200 3300 4400 0
0 0 50100 200 300 400
Km
25 50 100 150 200
Km
145 290 580 870 1160
Km Km
Fig.1. LocationofthecommunityofSucruiuzinho,municipalityofBrreiras,StateofBahia,northeasternBrazil.
agegroupswerebasedontheextentoftheageoftheyoungestto theoldestdividedintothethreeclasses.
The third indicator was measured by calculating the
con-nectance for each person in terms of medicinal plant learning
(numberofpeopleinthecommunityfromwhomtherespondent
learntaboutmedicinalplants/totalnumberofrespondents−1)so thatlargerconnectanceindicatethatthepersonacquires knowl-edgewithalargernumberofpeople.Thus,connectancevaluescan rangefrom0(therespondentdidnotlearnfromanyone)to1(the respondentlearnedfromallothersinthecommunity).Thisindex canshowiftheyoungerarestilllearningaboutmedicinalplants inthecommunity,althoughitdoesnotprovideinformationonthe intensityandnatureofsuchlearning.Inaddition,itconsidersonly currentandinternalrelationsofknowledgetransmission, disre-gardingotherpeople’sinformation(e.g.peoplefromneighboring
communitiesorformercommunitymembers).
Afterthecalculationweperformedasimplelinearregressionto testwhetherageinfluencesconnectance.Iftheregressionresults arenotsignificant,itwillindicatethattheyoungestarenotless connectedthantheeldersintermsofmedicinalplantlearning.
Results
Generalfindings
Thecommunitycitedatotalof162medicinalplants(Appendix). 149wereidentifiedtothegenusorspecieslevelandthirteencould notbeidentified.Themostimportantfamiliesintermsofnumberof specieswereFabaceae(nineteenspecies),Lamiaceae(ninespecies), Asteraceae(ninespecies)andAnnonaceae(sevenspecies).
Indicator1:age×numberofknownplants
Therewasnooverallrelationshipbetweenageandnumberof
knownplants(R2=0.11;p>0.05).However,ascanbeseeninFig.2, whentheregressionanalysisconsideredonlypeopleupto50years (Fig.3),wefoundastrongandsignificantrelationshipbetweenage andnumberofplants(R2=0.50;p<0.01).
Indicator2:age×therapeuticchoices
Therapeutic plurality issimilarly common inall ageclasses. Thus,therewerenodifferencesintheproportionsofcitationfor ‘plants’,‘allopathic’or‘bothstrategies’whenfacinganillnessevent
0 0 10 20 30 40 50 60
20 40 60
Age
Nº of species
80 100
0
14 24 34
Age
Nº of species
44 54
10
Fig.3.Relationshipbetweenageandnumberofmedicinalplantsknownby resi-dentsupto50yearsintheSucruiuzinhocommunity,Barreiras,Bahia,Brazil.
a
b
Both Allopathic Plants
c
Fig.4. Thetherapeuticchoicesaccessedfromthetherapeuticrecallconductedwith residentsoftheSucruiuzinhocommunity,Barreiras,Bahia,Brazil.(a)Between14 and36yearsold,(b)between37and59,and(c)between60and83years.The heightofthebarsisthenumberofrespondentsineachclassandthewidthofthe barsindicatesthecitationstoeachtherapeuticchoice.
0
0 20 40 60
Age
Connectance
80 100
0.1 0.2 0.3 0.4 0.5
Fig.5.Relationshipbetweenageandmedicinalplantlearningconnectanceby resi-dentsofSucruiuzinhocommunity,Barreiras,Bahia,Brazil.
(p>0.05)(Fig.4).Inthelastageclasswesawasmalltendencyfora greateruseofallopathic,althoughdifferencestotheotherclasses werenotstatisticallysignificant.
Indicator3:age×connectance
Youngpeoplearewellintegratedintermsofmedicinalplant
learning,asitisevidenttheyaregoingthroughlearningevents.
Theconnectancevaluesfortheyoungpeople(respondentsinage
class1)variedbetween0.1304and0.2173,beingsimilarorsuperior
tosomeoldermembersofthecommunityforwhichconnectance
valuesrangedfrom0.2173and0.3043.
Therewerenosignificantdifferencesbetweenyoungandolder peopleintermsoflearningconnectance(R2=0.04;p>0.05),which meansthateitheryoungorolderpeoplehaveexperiencedlearning
eventswithothercommunitymembers(Fig.5).
Discussion
Regardingthedifferenceofknowledgebetweenyoungpeople
andtheeldersindicatedhereandbysomeauthors(Reyes-García
lives (Henrichand Broesch, 2011)and therefore accumulateda
largerplantrepertoire. Thus, therelationshipbetween ageand
number ofcited plants alone doesnotallowus tomake
infer-encesonknowledgelossinacommunity,butmayindicatethat
theknowledgetendstobetransmittedandaccumulatedgradually,
exceptincommunitieswherethisknowledgeisquicklypassedin
earlylearningstages,aswillbeexemplifiedbelow.
Whenweevaluatethethreeindicatorstogether,wecanstate
that there is nolocal knowledge loss in the community, since
theyoungerusemedicinalplantsandallopathicinthesame pro-portionastheelders,whatcharacterizesapluralmedicalsystem (Vandebroeketal.,2004;Giovanninietal.,2011).Inaddition,young
peopleareconnectedtothecommunityasanyothermemberin
termsofmedicinalplantlearning,whatcanstrengthenthe
argu-mentthata loweramountofplants citedbyyoungpeopleis a
naturalprocess.Whenknowledgeonusefulplantsisrestrictedtoa groupduetotheinterruptionofthetransmissionmechanism,then
theriskoflossbecomesmuchlarger(AlbuquerqueandAndrade,
2002).
Theage-influencedincreaseinthenumberofplantsupto50
yearswassimilartothatobservedbyReyes-Garcíaetal.(2005).The maindifferencebetweentheirstudyandoursisthattheyfounda declineinknowledgeafteracertainage(55)andinourcase knowl-edgestabilizedfor50years ormore.Additionally,inaworkon
medicinalplantsperformedinaruralcommunityinNortheastern
Brazil,Silvaetal.(2011)reportedthatthemostknowledgeableage groupwaspreciselythe59–68yearsold,withadeclinein knowl-edgeafterthatagerange.Thesefindingsreinforcetheargument thatthere isa tendencyofself-reportedknowledgestabilizeor declineafteracertainage(Ayantunde,2008).Thiscanbeexplained
bytheassumptionthatoursynapsesarestrengthenedor
weak-enedbynewstimuli,experiencesandactions,whichenablesus
tolearnthroughoutlife,butafteracertainagetheformationof
newsynaptic connections becomemore rare and we have
dif-ficultiesin retainingnewdatain memory(Friedrichand Preiss, 2006).
Ourfindingsrelatedtotherapeuticchoicesaresimilartothose foundbyCeolinetal.(2011),whichshowthatmostparticipants involvedinhisresearch,whenfacedwithillnessevents,makeuse ofbothmedicinalplantsandformalhealthservices.Medical plu-ralisminthecontextofsomelocalpopulationscanbeexplainedby differentfactors,includingthefrequentcontactwiththeinfluential urbanarea(Giovanninietal.,2011)theperceptionofsomediseases asincurablebybiomedicine,suchasthe“spirit”disease,“evileye” orother“cultureboundsyndromes”(Amorozo,2004;Vossenetal., 2014);andincreasedeconomicpowerofsomepopulations(Quilan andQuilan,2007).Furthermore,theuseoftraditionalmedicineand biomedicinecanincreasetheamplitudeoftherapeuticchoicesthat humanpopulationuses,increasingtherangeofpossiblesolutions forthetreatmentofdiseases(Ryan,1998;Bhasin,2007).Thus,this setoffactorsjustifiesthetherapeuticchoicesandagainweakens
theargumentabouttheknowledgeloss,demonstratingthatthis
knowledgecanbehybridized(SoldatiandAlbuquerque,2012).
Thefindingconcerninglearningconnectancehasshownthat
young peoplebehave like theelders for this parameter.
How-ever,althoughlearningbehaviorissimilar,wealsoobservedthat
youngpeopledonotteachaboutmedicinalplantsthesameway
elders do, what can be expected since people often seek for
themostexperiencedwhentheywantinformationonmedicinal
Box1:Simulationofpossiblescenariosconsideringdifferentbehaviorsoftheindicatorsofknowledgelossonmedicinal plants.
Scenarios Combinations Interpretation
Knowledgeloss SituationA:
-Lessknowledgeofyoungpeople -Greateruseofallopathicbyyoungpeople -Youngpeoplewithlesslearningconnectance
Breaksintransmissionandabandonmentoftraditional practices
SituationB:
-Lessknowledgeofyoungpeople
-Greateruseofplantsorboth(plantsandallopathic)byyoungpeople -Youngpeoplewithlesslearningconnectance
Breaksinthetransmissionfromelderstoyoungpeople maycausetheknowledgeofyoungpeopletostabilize intheearlystagesoflife,sothatwhentheyreach adulthood,thisgenerationmayknowfewerplantsthan thelastadultgeneration
Withoutknowledge loss
SituationC:
-Lessknowledgeofyoungpeople
-Greateruseofplantsorboth(plantsandallopathic)byyoungpeople -Youngpeoplewithequalormorelearningconnectance
Graduallearning
SituationD:
-Therearenodifferencesinknowledgeregardingtheage
-Greateruseofplantsorboth(plantsandallopathic)byyoungpeople -Youngpeoplewithequalormorelearningconnectance
Knowledgetransmittedatanearlystage
Withoutcurrent knowledgeloss,but withsusceptibilityto futureloss
SituationE:
-Lessknowledgeofyoungpeople -Greateruseofallopathicbyyoungpeople
-Youngpeoplewithequalormorelearningconnectance
Preferenceforallopathicmaylimitthetraditional pharmacopoeiatospecificdisease(andplants), affectingthetransmissionofknowledgeaboutplants beforeemployedforpurposesnowdominatedby officialmedicine
SituationF:
-Therearenodifferencesinknowledgeregardingtheage
-Greateruseofplantsorboth(plantsandallopathic)byyoungpeople -Youngpeoplewithlesslearningconnectance
Improbablescenario,butthatmayindicate susceptibilitytofutureloss
ConditionG:
-Therearenodifferencesinknowledgeregardingtheage -Greateruseofallopathicbyyoungpeople
-Youngpeoplewithlesslearningconnectance
Improbablescenario,butthatmayindicate susceptibilitytofutureloss
SituationH:
-Therearenodifferencesinknowledgeregardingtheage -Greateruseofallopathicbyyoungpeople
-Youngpeoplewithequalormorelearningconnectance
Preferenceforallopathicmaylimitthetraditional pharmacopoeiatospecificdisease(andplants), affectingthetransmissionofknowledgeaboutplants beforeemployedforpurposesnowdominatedby officialmedicine
Thepossiblecombinationofbehaviorsforthethreeindicators ledustoproposedifferentscenariosforinterpretingknowledge loss(Box1).Inthiscase,theinteractionbetweenindicatorsmay
lead to three possible scenarios about knowledge loss. In
sce-nario1 wesimulatetwo situations inwhich knowledge lossis
more likely tooccur: (a)youngpeople knowless about plants
than theelders; their therapeutic choices are mostly based on
allopathic,andtheyarenotlearningaboutmedicinalplantswith
othercommunitymembers(conditionwithveryhighchancesof
loss); or (b) young people know less plants than elders, their
therapeutic choices are based on the use of plants (or both
plantsandallopathy),andtheyarenotlearningaboutmedicinal
plants withothercommunity members (local botanical
knowl-edgeofyoungpeoplewillremainbasedonasmallsetofplants) (Box1:AandB).
Thishypotheticalscenariomayberealasdriversofknowledge lossactconcomitantly.Forexample,thelossofbiologicaldiversity isalreadyidentifiedasalimitingfactorintherepertoireof medic-inalplantsofyoungpeople(Malthez-Stifeletal.,2012;Sujarwo etal.,2014)and,moreover,insomecontexts,theyoungpeople tendtobemoresusceptibletothechoiceofallopathictreatment ofdiseases(QuilanandQuilan,2007).
Inscenario2wesimulatetwosituationsinwhichthereisno
actuallossof LEK,asfollows(a)youngpeopleknowlessabout
plantsthanelders;theirtherapeuticchoicesarebasedontheuse ofplants(orbothplantsandallopathy),andtheyareconnected intermsofmedicinalplantlearning.Insuchcasewecanexpect thatthefewerplantsknownbytheyoungpeoplearetheresultof gradualknowledgetransmissionandthatthereisnotalossof cur-rentknowledge,asisthecaseofthefindingsofthisstudy.Another
possibilitywithinthescenario2isthat(b)agedoesnotinfluence medicinalplantknowledge;youngpeople’stherapeuticchoicesare basedontheuseofplants(orbothplantsandallopathy),andthey areconnectedintermsofmedicinalplantlearning.Basedonthis
model,wecansaythatknowledgeaboutplantsispassedinthe
earlystages(Box1:CandD).
Thescenario3hereproposedconsistsoffoursituationswhen
lossof currentknowledge maynotbeoccurring,butindicators
pointfuturevulnerabilitytoknowledgeloss.Forexample,(a)young peopleknowlessaboutmedicinalplantsthanelders;their
ther-apeuticchoices arebasedonallopathy,andtheyareconnected
intermsofmedicinalplantlearning.Thisconditiondenotes cer-tainvulnerabilityinthesystem,sincelearningmayberestricted tofewplantsthatstillplay arolein youngpeople’shealthcare. In anothermodel (b) forthis scenario thereis nodifferencein
knowledge regarding age; youngpeoplehave theirtherapeutic
choices based onthe useof plants (orboth plants and
allopa-thy),buttheyareweaklyconnectedtothecommunityinterms
ofmedicinalplantknowledge.Suchmodelalsoindicatesafuture vulnerabilityinknowledge,sinceinterruptionsinmedicinalplant
learningprocessmaypreventnaturalandgradualacquisitionof
new information, bringing knowledge to stabilize in the early
stages.
Finally,therearestill twosituationswhen theknowledgeof
youngpeopleandeldersaresimilar;youngpeoplechoosemore
Werecommendthatfuturestudiesconsiderajointassessment ofthefactorsproposedhere,inordertoavoidinadequate conclu-sionsbasedonindicatorsthat,usedinisolation,maynotleadtoan accuraterepresentationofthestudiedreality.
Thestudyhasthefollowinglimitation:sincewedealtonlywith internalcommunitynetworks,wecannottellifthereare
differ-encesbetweentheyoungestandtheeldestintermsofexternal
learning(learningwithpeoplefromotherregions).Therefore,the resultthatshowednodifferenceintermsoflearningnetworksis onlyvalidforinternallearningandwethinkfuturestudiescould alsoinvestigatelearningoutsidethestudiedcommunities
Ethicaldisclosures
Protectionofhumanandanimalsubjects. Theauthorsdeclare
thatnoexperimentswereperformedonhumansoranimalsfor
thisstudy.
Confidentialityofdata. Theauthorsdeclarethattheyhave
fol-lowed theprotocolsof theirworkcenter onthepublication of
patientdata.
Righttoprivacyandinformedconsent. Theauthorsdeclarethat nopatientdataappearinthisarticle.
Authors’contributions
CCBcontributedinfieldworkandwrotethefirstversionofthe MS,TCSmadeacriticalreadingandconsiderablychangedtheMS, UPAmadeacriticalreadingandconsiderablychangedtheMS,MAR
madea criticalreadingand considerablychangedtheMS,WSFJ
madeacriticalreadingandconsiderablychangedtheMS,FNB con-tributedinfieldworkandhelpedwritingthefistversionoftheMS, EMCNco-directedtheMastersdissertationofthefirstauthor,PMM idealizedthestudyanddirectedtheMastersdissertationofthefirst author.
Conflictsofinterest
Theauthorsdeclarenoconflictsofinterest.
Acknowledgments
TheauthorsthankUniversidadeFederaldaBahiaforthegrant giventothelastauthor.TheythankCAPESforthefellowshipgiven tothefirstauthor.TheauthorsalsothankUniversidadeFederaldo OestedaBahiaforfundingtheMStranslation.Specialthanksare
giventoallmembersofSucruiuzinho,whokindlyacceptedtobe
interviewed.
AppendixA. Supplementarydata
Supplementarydataassociatedwiththisarticlecanbefound,in theonlineversion,atdoi:10.1016/j.bjp.2016.09.006.
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