Contents lists available atScienceDirect
Urban
Forestry
&
Urban
Greening
jo u r n al ho me p a g e :w w w . e l s e v i e r . c o m / l o c a t e / u f u g
Allotment
gardens
and
parks:
Provision
of
ecosystem
services
with
an
emphasis
on
biodiversity
A.F.
Speak
a,∗,
A.
Mizgajski
b,
J.
Borysiak
baDepartmentofGeography,UniversityofManchester,OxfordRoad,Manchester,UK
bDepartmentofIntegratedGeography,AdamMickiewiczUniversity,FacultyofGeographicalandGeologicalScience,Dzi˛egielowa27,Pozna´n,Poland
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received21April2015
Receivedinrevisedform13July2015 Accepted14July2015 Keywords: Allotmentgardens Biodiversity Ecology Ecosystemservices Parks Urbanagriculture
a
b
s
t
r
a
c
t
Urbanareas,inparticular,presentuniquechallengesfortheconservationofecosystems.Allotment gar-dens(AGs)areanimportantgreenspacefeatureofurbanlandscapesinEuropewhichhavethepotential tooffermultiplesocialandbio-physicalecosystemservicesinadditiontofoodproduction.Thisstudy isanattempttoassessandcomparetheecosystemservicesprovidedbyAGsinManchester,UK,and Pozna ´n,Polandaswellasacomparisontocityparks.Thesurveysincludedadetailedlandcover char-acterisationandanassessmentofcultivatedandspontaneousplantspecies.Therearedifferencesinthe landusecharacteristicsinthetwocitieswithapreferenceforvegetablegrowingandwaterrecyclingin Manchester,andagreaternumberoftreesandahigherfocusonrecreationinPozna ´n.Theconsequences ofthesebasicdifferencesarediscussedintermsoftheecosystemservicesthatareprovidedbythetwo differentAGtypes,andparks.Intermsofecology,thereishigherspeciesrichnessonAGswithagreater proportionofneophytes,whichmaypotentiallyspreadintocities.ThespeciesrecordedinparksandAGs containedalotofnativecharacteristicsofurban,ruderalplantcommunities.
©2015ElsevierGmbH.Allrightsreserved.
Introduction
Ecosystem services is a very attractive research field docu-mentedbyarapidincreaseintheamountofpublicationsduringthe lastdecade(CostanzaandKubiszewski,2012).Thisapproach, pro-vidingvalidargumentsfornatureprotection,isincreasinglybeing recognisedforitsimportanceingovernmentpolicyandpractice (Haines-YoungandPotschin,2008).Interestinservicesofurban ecosystems(BolundandHunhammar,1999)appearedverysoon aftertheevaluationofworldecosystemservicesbyCostanzaetal. (1997).
Urbanareasbenefitfrominternalecosystemswhichareoften threatened.Rapidurbanisationis destroyingnatural ecosystems and harming the environmental quality of towns (Alberti and Marzluff,2004).Europeancities havegrownrapidlysince 1950 withlittleattentiontothecreationofinnercitygreenspaces.This resultsinareasofthecity,ofvaryingaffluenceandbuildingdensity, withlowgreencover,especiallytrees,andwithconsequent nega-tivelocalenvironmentalimpacts(Pauleitetal.,2005).Conservation andrestorationofecosystemservicesinurbanareascanreducethe ecologicalfootprintsofcitieswhilstenhancingresilience,health,
∗Correspondingauthor.
E-mailaddress: andyspeak33@gmail.com(A.F.Speak).
and quality of life for theirinhabitants (Gómez-Baggethun and Barton,2013).
UrbanAllotmentGardens(AGs)havebeenshownthroughout historytobeanimportanturbangreenspacethatcancontribute totheresilienceofcities,especiallybyprovidinglong-termfood securityintimesofenergyscarcity(BarthelandIsendahl,2013). Modernurbanagriculturecannotfeasiblyprovidefoodforallofa city’sresidents,butitcanbeasignificantsourceoflocallygrown food.ThiswasseeninCubawithanestimated1in10residents ofHavanabenefittingfromthefoodgrownintheurbangardens (Moskow,1999). Importantly,AGsprovideadditionalecosystem servicesbeyondfoodproductionsuchaspollination(Ahrnéetal., 2009),localclimateregulation,floodprotectionandanopportunity tosocialiseinapleasantenvironment.
Thereiscurrentlyaneedtoquantifytherangeofecosystem services specifically provided by AGs sothat their value as an urbanlanduse canbefullyrecognised.Quantificationof trade-offsamongecosystemservicesandtheirinteractionswithhuman well-being areamongthemostpressingareasforresearch.The generalincreaseinprovisioningservicesoverthepastcenturyhas beenachievedattheexpenseofdecreasesinregulatingandcultural services(Rodriguezetal.,2006).
Generally AGsshouldrepresenta ‘win-win’situation inthis respectbecausetheyoffermultiplebenefitsbeyondfood produc-tionanddonotincurseveretrade-offsinotherservicesasaresult http://dx.doi.org/10.1016/j.ufug.2015.07.007
of theirlandmanagementpractices.Climate changeadaptation policiesforcitiesrelyheavilyonthepreservationof,andcreation ofnew,greenspace.ThereforeitispossiblethatAGscanplaya roleinthisimportantfield.Thereductionoffoodmilesassociated withlocally-grownproducealsofitsintoclimatechangemitigation policies(Lwasaetal.,2014).
ThesubjectofthisstudyistopresentdifferencesbetweenAG ecosystemsandtheir servicesdependingonthemannerofuse, whichvariesconsiderablybetween nations.InPoland,AGshave existed for over 100years butthey have played a very impor-tantrole sincecommunisttimes;in theyear1949aspecialact wasdevotedto‘worker’sgardens’.Citieswithover50,000 inhabi-tantswereobligedtoestablishallotmentsineveryneighbourhood wheretheproportionoftowerblockdwellersexceeded20%. Cur-rentlyAGsinPolandoccupy40,000haandinvolveabout700,000 users(PZD,2014).Polishallotmentgardenerscollectively repre-sentthelargestlandmanagersinPoland(Bellows,2004)andplay animportantpoliticalroleasanelectorategroup.
In theUK, allotmenttenancy reachedits peakduring WWII thankstothe‘Digfor Victory’campaign.Duringwartime, allot-mentsandgardensproducedabout10%ofthefoodconsumedin theUK(CrouchandWard,1997).Afterthewar,the‘growtoeat’ imperativeeasedandlandwasrequiredforbuildingnewhouses andschools.AGnumbersdeclinedfromnearly1.5millionin1950to 250,000today(NaturalEngland,2007).UrbanAGsareunderthreat todaybecausethelandisoftenquitecentralandhighlyvaluedby landdevelopers(NaturalEngland,2007).
Theaimofthisstudyistoestimatedifferencesbetween ecosys-temsandtheservicesprovidedbythemonAGsinPolandandthe UK,usingexamplesfromPozna ´nandManchester.The compara-tivestudy,usinghighintensitysamplingdataatthelandusetype scale,allowstheassessmentoftwodifferentAGtypologies,anda thirdlandusetypeofurbanparks.Ecosystemservicequantification workisscarceatthescaleoflocallandusetypes(DeGrootetal., 2010).Thestudyalsobenefitsfromauniqueinvestigationintothe spontaneousfloraldiversityofAGsandparks.Ecosystemservices areoftenreliantonthefunctionaltraitsoftheunderlyingplant communities(DeBelloetal.,2010)andfloraisagoodindicationof biodiversity,asitisflorawhichshapesthestructureoforganisms athighertrophiclevels(Smithetal.,2006).Spontaneousfloraisnot onlyabio-indicatorofecologicalfunctionsservedbythe environ-mentbutalsoarecordofthesynanthropisationprocess(Borysiak etal.,2014)
This study thus provides a comprehensive snapshot of the ecosystem service provision capacity of an oft-overlooked, but important,urbanlanduse type.Thefew quantitativestudiesof communitygardensthatexistuseplantsurveys,beecollectionand soiltesting(Guitartetal.,2012),butnostudiescharacterisetheland useonAGsintermsofthespatialbio-physicalstructure.
Methodology
Studysites
ThecitiesofManchester(UK)andPozna ´n(PL)represent differ-encesintheroleandmanagementpracticesofAGsoccurringin westernandcentralEuroperespectively.Manchesterisalargecity situatedinnorth-westEngland.TheManchestercitydistrict,which includesthecentreoftheGreaterManchesterconurbation,hasa populationofover514,000(UKstatistics,2014).TheGreater Man-chesterconurbationcontainsafurtherninedistrictsgivingatotal populationof2.7million.Pozna ´nislocatedinthewestofPoland. ThecitypopulationofPozna ´nisaround550,000,with1.3million peopleinthemetropolitanarea(CSOP,2014).Thetwocitiesare thusofcomparablepopulation;however,Table1showsthatthe
Table1
Maincharacteristicsofthetwostudysites(spatialanalysisundertakeninArcGIS andusingdatafromCSOP,2014).
Manchester Poznan Numberofallotmentcomplexes 40 83 Districtarea(ha) 11,564 26,153 Allotmentsarea(ha) 49.1 848.5 Allotmentareaproportion(%) 0.4 3.2 Meanallotmentarea(ha) 1.2 10.2
two cities differ considerably in terms of AG provision. Seventeen times as much land area is given over to AGs and there is an eight-fold increase in the proportion of land cover which is AGs in Pozna ´n. The allotment complexes themselves are also roughly eight times larger in Pozna ´n.
Site visits were undertaken from May to July 2014 to coincide with vegetation being in peak growth and with inflorescences to facilitate identification. Twelve allotment complexes and two parks were visited in Pozna ´n, and nine allotment complexes and eight parks were surveyed in Manchester.
Botanicalsurveyandlandusequantification
For all land types, spontaneous plant species growing in the paths, verges, and abandoned areas were identified usingHarrap’s (2013)‘WildFlowers’fieldguide.Theplantspecieswereclassified asnative,ornon-nativearchaeophyte(introducedbefore1500)or neophyte(introducedafter1500)(Pyˆsek,1995)usingtheAtlasof BritishandIrishFlora(Prestonetal.,2002)for Manchester,and Tokarska–Guzik(2005)forPozna ´n.TheRaunkiaer’slife-formwas alsorecorded(Zarzyckietal.,2002).TheecologysurveyofPozna ´n AGswasundertakenbyoneauthorandalltheotherecologyand landuse survey workin both citeswas carriedout byanother author,thereforeecologyresultsarepresentedseparatelyand com-parisonsarequalitative.
SatelliteimageswereusedwithinArcGIS10tocalculatepark, allotmentandaverageplotareas.Thesatelliteimagesaredated 2009(Manchester)and 2011 (Pozna ´n)and were both taken in summer.Polygonsweredrawntoapproximatetheproportionof landsurfaceareawhich is undertreecanopy.Thiswasa fairly straightforwardvisualtask,asthesummerimagesallowforeasy identificationofbothevergreenanddeciduoustreecanopies. Dur-ingsitewalkovers,thefollowingprocedureswerecarriedout:
•Treescountedandidentified,andheightestimatedtothenearest metreusingtapemeasureandvisualextrapolation.
•Proportionofcultivatedgroundineachplotestimatedas:zero;a third;ahalf;twothirds;orfullycultivated.Anabandoned, over-grownplotrepresentszerocultivationanda plotwithahigh apparentlevelofmaintenance(weeding,mowing)onall avail-ablelandisdescribedasfullycultivated.
•Alistofvegetablesgrownoneachallotmentcomplexwas com-piled
•Thenumberofplots ineachallotmentcomplexgrowingfruit and/orvegetableswasnoted.
•Areaoflandusedbybuildings(sheds,greenhouses,polytunnels) andpavedpaths/patiosestimatedbyeyeandoccasionally mea-suredusinga tapemeasurewhereaccesswasgranted.Itwas notedwhetherabuildingwascollectingroofrainwaterrunoffin acontainer.
•Allotment holders were interviewed to identify additional ecosystemservicestotheprovisioningandregulatingservices quantified.
Table2
Summarystatisticsforstudysitearea.
Manchester Poznan Parks
n 9 12 10
Meanarea(m2) 15,091 39,470 13,072
Medianarea(m2) 8072 40,020 9493
Arearange(m2) 1597–51,315 23,961–64,357 3368–37,180
Table3
Summarystatisticsforindividualallotmentplotarea.
Manchester Poznan
n 497 1164
Meanarea(m2) 211 369
Medianarea(m2) 205 335
Arearange(m2) 107–375 305–560
Due to privacy issues, most allotment surveying was carried out from the paths outside the plots unless invited onto the plots by the owners.
Tables2and3showtheareasoftheallotmentsinthisstudy, selectedtocoverawiderangeofsizesandlocations.Themean aver-ageallotmentcomplexareasampledinPozna ´nissmallerthanthe citymeaninTable1becauselargercomplexeswerenotsurveyed intheirentiretyduetotimeconstraints.Datawerenotnormally distributedandare presentedin non-parametricboxplots, and mediansusedforcomparisons.Naturallogarithmsofspecies rich-nessandplotareawereusedtotestspeciesequilibrium theory (Crowe,1979).StatisticscalculatedusingRv2.15.2.
Ecosystemservicesassessment
A list of ecosystem services appropriate to urban AGs was selected based on the Common International Classification of EcosystemServices(CICES)V.4.3compiledbytheEuropean Envi-ronmentalAgency(Maesetal.,2014).Particularservicesbelonging to one of three groups—Provisioning, Regulating and Cultural services—have been assessed using an approach presented by Burkhardetal.(2012),whousedascaleof0–5with0beingno relevant capacity ofthe landtoprovide a particularecosystem service,and5beingveryhighrelevantcapacity.Scoringof ecosys-temserviceprovisionforthelandusetypesinthisstudywasbased onsimilarlandusetypesinBurkhardetal.(2012)andontheuseof personaljudgementwhiletakingintoaccounttheextensive quan-tificationworkundertaken.
Results
EcologyinManchesterAGsandparks
Fulllists ofspontaneousvegetation and treesin Manchester andvegetablesgrownareavailableinthesupplementarydata.The mainfindingsaresummarisedinTable4.Thespeciesrichnessof spontaneousfloraismuchhigheronAGs.Manchesterparkshave roughly65%ofthespeciesrichnessofManchesterAGs.Allotment florabelongstoagreaterrangeoffamiliesthantheparkflora.In additionthefamiliesfoundinparkscouldallbefoundonAGswith theexceptionofAsparagaceae(onespecimenofHyacinthoides non-scripta).Speciesrichnesstendstoincreaseastheareaofsurveyed plotincreasesbutthisrelationshipisnon-linearasitwould even-tuallyplateau.Theaveragesiterichnessperhectarevariedgreatly, withoneallotment(HoughEnd)beingsmallinareabutwithalarge speciesrichness.
Speciesrichnessequilibriumtheorypredictsthattheslopeof alog–logplotfallsbetween0.20and0.35asCrowe(1979)found forabandonedurbanlotsinChicago.Theslopeis0.25(R2=0.265,
Table4
Summaryoftheecologicalsurveydata.
Manchester Poznan Parks Overallspeciesrichness 87 357 56 Plantfamiliesrepresented 34 70 19 Speciesuniquetothelandusea 47 17
Plantfamiliesuniquetothelanduse 16 2 Overallspeciesrichnessperhectare 6.4 2.4 4.2
Averagesiterichness 48 25
Treespeciesrichness 28 33
Treefamiliesrepresented 14 13
Treespeciesuniquetothelanduse 12 18 Treefamiliesuniquetothelanduse 5 4
aSpeciesfoundonlyinthatlandusetypeinthepresentstudy.
Fig.1.Log–logplotofspeciesrichnessagainstareaforManchesterallotmentsand parks.
O=allotments,X=parks
p< 0.05) (Fig.1)which indicates equilibrium;therefore species richness isafunctionofareaanddegreeofisolationfromother greenspaces.Fig.2 showsthatlargerproportionsofneophytes weretobefoundinallotments.Widespreadspecies,foundinboth landtypes,aredominatedbynativespeciesandtheymakeup70% ofalltheplantsrecorded.
ThedominantUKspeciestendedtobegrasses(Agrostissp.and
Loliummultiflorum)andwhiteclover(Trifoliumrepens)whichwere foundin thepathsof allotments.Associated withtheseground cover specieswould befoundfrequentlyPlantagomajor, Rumex obtusifolius, Taraxacum agg. and Ranunculus repens. The verges andabandonedplotsofallotmentswerefrequentlydominatedby
Urticadioica,GaliumaparineandGeraniumrobertianum.Ofthelife forms,55%werehemicryptophytes,32%therophytesandtherest werechamaephytesandgeophytes,withonenanophanerophyte (Rubusfruticosus).
NoneofthespontaneousspeciesfoundonManchesterAGswere ofanyspecificecologicalinterestorclassifiedasendangeredor vul-nerableontheUKvascularplantsreddatalist(CheffingsandFarrell, 2005).Twoofthespeciesare,however,classedasnuisanceinvasive species:ImpatiensglanduliferaandFallopiajaponica(Environment Agency,2013).
Treespeciesrichnesswasslightlygreaterinparks.Thespecies foundonlyonparksincludedmoreornamentaltreessuchasCornus
Fig.2.Pie-chartstoshowtheproportionsofnativeandnon-nativespeciesfoundinthetwolandusetypesinManchester.
speciesfoundonlyonAGsincludedmoreediblefruittreessuchas
Ficuscarica,OleaeuropaeaandPyruscommunis. EcologyinPozna´nAGs
InPozna ´nAGs357speciesofvascularplantswerefound(data notshown).Thelistincluded256(72%)spontaneophytesand101 (28%)geographicalienspecies.Theseproportionssignifiedavery highlevelofnaturalnessoftheAGflora.Amongthealiens, archaeo-phytes(59species,17%)prevailedoverneophytes(42,12%).Among thelifeforms,hemicryptophytes(192,54%)andtherophytes(119, 33%)weresignificantlydominant.Therophytes(49)constituteda highpercentage(83%)ofarchaeophytes(59).Theallotment com-plexesweregreenurbanareaswithahighnaturalvaluethanksto: 44(12%)threatenedspecies(hemerophobic)inthePozna ´narea,61 (17%)plantsatriskintheEuropeanUnion,32(9%)cropwild rela-tivesatriskofdeclineinEuropeanUnioncountries,22(6%)ancient woodlandindicatorsand58(16%)speciesthatarebioindicatorsof theNatura2000EuropeanEcologicalNetworkhabitats.
InPozna ´n,speciesrichnessperhectareislowerthanManchester AGsandparks,despitethemuchlargerspeciesrichnessingeneral, duetotheverylargeareacoveredbyAGs.
Provisioningservices
OneofthemaindifferencesbetweentheAGsinthestudyis howtheyareusedforfoodproduction.Fig.3showsthatallthe occupiedplotsinManchesterareusedforgrowingvegetables.In Pozna ´nonlyathirdofplots,onaverage,wereobservedtobe grow-ingvegetablesandthisusuallyconsistedofavegetablebedwitha meanaveragesizeof30m2(lessthan10%oftheaverageallotment
area).Alotofsimilaritiesareapparentinthediversityofvegetables growninthetwocountriesbutthereweresomenotablecultural differencesintheamountsofthevegetablesgrown.Forexample, kohlrabiandceleryareverypopularvegetablesinPolandbutnotso commonintheUK(andwereeachonlyobservedgrowingonone singleallotmentplot).However,thevarietyofvegetablesgrown waslargerin Manchester, withmore allotmentholders experi-mentingwith‘exotic’vegetableslikecucamelonandtomatillofrom CentralAmerica.
More of the AG land is fully cultivated in Pozna ´n than in Manchester(Fig.4).Thisisdue toa largerproportionof totally abandonedplotsandplotswithovergrownsectionsinManchester. Dataonthehighestyieldavailableforthevegetabletypesgrown wereaveragedandmultipliedbytheareaofcultivatedlandused forgrowingvegetablestoderiveestimatesoftheyieldonthe allot-ments(Table5).ItisclearthateventhoughManchesterallotments aresmallerintotalarea,thereismorelandusedforvegetables, resulting inaneightfold yield increaseover Pozna ´nallotments. Whenthelandareagivenovertovegetablecultivationisusedto
Fig.3.Proportionofnon-abandonedallotmentplotswhichgrowvegetables.
Table5
Summarystatisticsforallotmentfoodproduction.Potentialyieldisbasedondata fromMobbs(2002)andconsideringonlythevegetablesfoundtogrowinthestudy sites.
Manchester Poznan Areavegetableproduction(m2) 89,090 11,070
%oftotalarea 65.6 2.3
%ofnon-pavedarea 70.7 2.7
Meanpotentialyield(t) 615 76
Financialvalueofyielda £310,900 £38,600
Financialvalueperallotment £698 £104
aCalculatedbyaveragefinancialproductivityperm2of£3.49basedondatafrom
160allotmentsinLondon,UK(Sustain,2014).
calculatethefinancialvalueofthepotentialyield,grossbenefitsof
£
310,900(£
698perplot)canbeexpectedinManchester.AllotmentsinPozna ´nhadroughlydoubletheamountoffruit treesthanManchester(Fig.5).Apricotandpeachtreesweremore commonin Pozna ´nand mostallotmentshadatleastoneapple orcherrytree,eveniftheywerenotgrowinganyotherfruitor vegetables(datanotshown).Walnuttreeswereverycommonin Pozna ´n.ApricotandpeachtreesareseldomfoundinManchester,
Fig.4. Degreeoflandcultivation.
Fig.5.Numberoffruittreesgrowingperhectareinthethreelandusetypes.
duetoclimateand/orculturaldifferences,butagainManchester experimentswithunusualtreessuchasfiganddamson.Fruittrees areoccasionallyfoundinpublicparksandcherrytreesdominate, withsomeappletreesfoundoccasionally.
Itwasapparentthatanumberofplots,inbothcities,were grow-ingmedicinalherbs.TheseincludedMelissaofficinalis,Menthasp., andHypericumperforatumwhichallhavemedicinalusesinaddition toanyculinaryuses.Severalallotmentholderssaidtheyregularly drinkherbalteasmadefromsomeoftheseherbsforthe promo-tionofwell-being.Additionally,chickenswerekeptonacoupleof Manchesterallotments,providingfoodfromlivestock.
Fig.6.Proportionoflandsurfaceareaundertreecanopies.
Fig.7.Meanaveragetreeheight.
Regulatingservices
Theproportion oftreesand thefloral diversityarethemain elementsdividingthelevelofregulatingservicesbetweenAGsin Pozna ´nandManchester.Themassratiohypothesisstatesthattraits ofthedominantspeciesbymassinacommunityexertakeyeffect onecosystemprocesses(Grime,1998).Traitssuchascanopysize, growthform,leafmorphology,andtissuechemistrywerethefour mostexaminedinrelationtoecosystemservicesintheliterature (DeBelloetal.,2010).
ForthetwoAGtypes,greatdifferencesintreecoverandspecies compositionareobserved,withtreecoverinPozna ´nbeing sim-ilartothatofparks (Fig.6).Pozna ´nAGshavemanymoretrees, ofagreatersize,andwithahigherproportionofevergreentrees (tallcypresshedgesandindividualconifertrees)thanManchester (Figs.7–9).Parkshavethegreatestnumberoftallertrees.
Fig.8.Numberoftreesperhectareseparatedbythreetreeheightbrackets.
Fig.9.Percentoftreesencounteredwhichareevergreen.
Theproportionofthelandgivenovertoimpermeablesurfaces (Fig.10)didnotvaryconsiderablybetweenthelandtypes.Pozna ´n AGshadthemostbuildingsbutManchesterAGsoccasionallyhad largeareaspavedforcarparksandpaths.Parkswithhighamounts ofpavedareasusuallycontainedfeaturessuchastenniscourtsand children’splaygrounds.
ManchesterAGholdersaremuchmorelikelytocapturerainfall runofffromshedsandgreenhousesforuseindryperiods(Fig.11). Manchester’saverageannualrainfall(fortheperiod1981–2010) is828.8mmandthatofPozna ´nis515mm.Assumingallthe rain-fallfallingonsurfacesconnectedtobarrelsiscollected,thisgives totalvolumescollected of1295m3 in Manchesterand 2239m3 inPozna ´n.ThegreaternumberofbuildingsonPozna ´nallotments meansthatthetotalvolumecapturedislarger;therefore, normal-isingfortotallandareagives12.6l/m2collectedinManchesterand
5.1l/m2inPozna ´n.PondswerecommoninbothManchesterand
Pozna ´n;however,in Pozna ´nthepondsweremoreforaesthetic purposesthanforbiodiversityorrainwaterstorage.Thepondsin Manchesterallotmentswerelesswellmanicuredandtheyappear toplayamuchmoreecologicalrole,e.g.providingahabitatfor frogs,whichhelpcontrolgardenpestpopulations.
Fig.10. Percentagelandsurfaceareapaved(paths/buildings).
BeehiveswerealsofoundontwooftheManchesterallotments, thusenhancingpollinationasanecosystemservice.
Culturalservices
AGscanscorehighlyonecosystemservicessupportingsocial life.Socialbenefitsinclude:socialcohesionbroughtaboutby bring-ingtogetherpeopleofdifferentbackgroundswithasharedinterest ingardening;educationaboutnatureandfood production;and healthbenefitsbymoderatephysicalactivity,especiallyforelderly people.
Information gained from interviewing AG holders revealed Pozna ´nAGstoprovideanimportantrecreation servicebecause theyaretreatedlikesummerhomes,whichtenantsactuallymove tointhesummermonths.Outdoordining,sunbathingand enter-tainingfriendsarecommonactivities.OnManchesterAGs,tenants spendmuchlesstimeontheplotsanditisusuallytoundertake gar-deningworkandchattoothertenants.However,ManchesterAGs wereoftenusedforeducationonsustainabilityandfoodgrowing techniquesforcommunitygroupsandschools.
Fig.11.Percentageofthebuildinginfrastructurefittedwiththemeansforcapture andstorageofrainwater.
Discussion
Ecology
ThelowerspeciesrichnessinUKparksisa resultofthe dif-ferencesinlandmanagementpracticesbetweenparks andAGs. Parksaremowed frequentlyandthereare alimited numberof specieswhichcansurvivethisregulartreatment,suchasgrasses andlow-growingplants(Stellariamedia).Mostofthespecies rich-nessinparkswasfoundinthevergesandunderbenches(personal observation),thatescapemowingpressure.Disturbances,suchas mowing,preventthecompetitivereplacementofpioneer colonis-ers (Haigh,1980).Managementregimes on someUKparks are recognisingthepotentialthatparksholdforimproving biodiver-sity,andareasareleftunmaintainedwhichconsequentlybecome richinmeadowspecies.Threeoftheparksinthepresentstudyuse thisstrategy,andconsequentlyhadhighspeciesrichnesscompared tootherparks.
ThespeciesrecordedinManchesteraresimilartothoseofan urbanruderalcommunitysurveyedinBirmingham(Haigh,1980) givingstrengthtotheideathaturbanareashaveuniqueand consis-tentplantcommunityassemblages.Thewidespreadspecieswere mostlynative,withthemajorityoftheneophytesappearing on allotments,presumablyasaresultofintroductions,andsubsequent escape,ofnon-nativesbyallotmentgardeners.Thisisincontrast totheproportionofnativeplantsindomesticgardens.Lorametal. (2008)foundonly30%ofplantsindomesticgardenstobenative, butgardensarehighlymanagedspaceswithapreferencefor orna-mentalspeciesandtheremovalofnativeweeds.
Onallotmentsthereisadifferentselectionpressuretothatof parks—regulardiggingandupheavalofthesoil.Thismakes allot-ments highly suitable environments for a wide range of weed speciesthatexhibitoneormoreofthefollowingtraits:longlived seed;rapidgrowthtofloweringstage;easeofgermination; self-compatibility;highseedoutput;goodcompetitors;andvigorous reproductionfromfragments(CousensandMortimer,1995).The high proportionof therophytesin bothcountries wasgenerally foundinareassubjectedtodigging.Ruderalplantsarevery com-moninsuch highdisturbance,lowstressenvironments(Grime, 1977).Inaddition, practicesonallotments whichenhance crop
vegetableproductioncaninadvertentlystimulateweedgrowthe.g. additionoffertilisers,soilwarminginwinter.
ThereweredifferencesinthespeciescompositionbetweenAG complexes withinManchesterindicatingthepotentialinfluence ofthesurroundingland-use.ThehighspeciesrichnessonHough End(Manchester)AGscouldbeexplainedbyitsproximity down-windofalargeexpanseofparks,wastegroundandwoodlandwhich would providean externalseed input.Managementdifferences on the AGs themselves may also explain some of these inter-allotmentdifferences.Anallotmentcomplexwithahighnumber of abandoned plots would have a large internal inputof wind andanimal-dispersedseeds.Theecologicalpotentialofovergrown, abandonedplots(whichFig.4showscanbequitesignificantin termsoflandcover)ishigh,asmanyofthespontaneousplantswere foundintheseareas,andtheycanactaswildliferefuges(Natural England,2007).
TherewassomeevidenceonacoupleofAGsofculinaryspecies that were likelyplanted onAGs and have subsequentlyspread to thepaths and verges, such asOriganum vulgare and Melissa officinalisinManchester.AGsmayprovideapathwayforthe intro-ductionofnovelneophyteinvasivespeciesintocities.
Pozna ´nAGshadanimpressivespeciesrichness.Thepresence ofthreatenedspeciesisanimportantresult,whichhighlightsthe potentialofAGstoplayaroleinplantconservation.Itisinteresting thattheproportionofgrowthformsrepresentedishighlysimilar inManchesterandPozna ´nandthisreflectsthegrowthstrategies thataresuitableforahighdisturbanceurbanlanduse.
Intermsofecosystemservices,someofthespontaneousspecies recordedaregoodforpollinatorinsects,suchasEpilobium angusti-foliumandmembersoftheGeraniumgenus.Thisisnottomention thewiderangeofvegetablesandornamentalflowersgrownon AGs,whichprovidepollenandnectarsources.AstudyinGermany foundover2000cropandornamentalspeciesonAGs(BDG,2008). AGsinStockholmwerefoundtobefunctionallyconnectedby for-agingbees,butthepollinationecosystemserviceisweakerinareas strongly influenced by humanactivity, as measured by imper-vious surface proportion (Ahrné et al., 2009). Other ecosystem servicesarisingdirectlyfromthespontaneousvegetationinclude wildfoods,nutrientregulationandintrinsicvalueofbiodiversity.
TheresultsofthisstudyshowthatAGscanbehighly species-richenvironmentsandmayofferamethodoffoodproductionthat doesnotincurasmanytrade-offswithbiodiversityasotherland uses(Rodriguezetal.,2006).
Ecosystemservices
Thusfarwehavediscussedtheecosystemservicesrelatedto plantdiversityonAGs.Inthissectionweevaluatethetotal ecosys-temservicesprovidedbythedifferentlanduses.Table6liststhe servicesprovidedbytheAGsandUKparks.Betweenthetwocities therearesubtledifferencesrelatedtodifferentAGmanagement practices.Forexample,thepresenceofbeehivesandlivestockon ManchesterAGsgavehigherscoresinthepollinationandlivestock categories.Intermsofculturalservices,parksarehighlycommunal spacesthatcanbeusedbymanypeople.AGstendtobefencedoff andstrictlyfortheuseoftenantsonly,duetoissueswithvandalism andtheft.ThislimitstheimpactofAGsintermsofprovidinglarge numbersofcityresidentswithaccesstogreenspace.However,a recenttrendintheUKistocreatecommunityAGsthatcanbeused bylargegroupsofpeoplesuchasschools.
Parks generally lack theprovisioning services foundonAGs but give importantbenefitsrelated to trees.Evergreen treesin particular,arehighlybeneficialbecausetheypotentiallyprovide multiple ecosystem services, related to leaf area index, year-round.Areviewof115treeresearchpapersfoundcarbonstorage, air qualityimprovement, microclimatemodificationand energy
Table6
Matrixfortheassessmentofthedifferentlandcovertypes’capacitiestoprovide ecosystemservices.Theassessmentscalecovers0=norelevantcapacity,1=low rel-evantcapacity,2=relevantcapacity,3=mediumrelevantcapacity,4=highrelevant capacityand5=veryhighrelevantcapacity.
Ecosystemservice Manchester Poznan Park
Provisioningservices 20 18 6 Crops 5 5 1 Livestock 2 1 0 Fodder 4 4 0 Wildfood 2 1 1 Woodfuel 1 2 1 Geneticresources 4 3 2 Medicine 2 2 1 Regulatingservices 19 22 22
Localclimateregulation 3 4 4
Globalclimateregulation 1 2 2
Floodprotection 1 1 1
Groundwaterrecharge 2 2 2
Airqualityregulation 2 3 3
Erosionregulation 2 2 2 Nutrientregulation 1 1 1 Waterpurification 1 1 1 Pollination 4 3 2 Noisereduction 2 3 4 Culturalservices 18 17 18 Recreation 3 4 5
Intrinsicvalueofbiodiversity 2 2 1
Aestheticvalue 3 3 4
Socialrelations 3 3 3
Knowledgesystemsandeducation 4 2 2
Culturalheritage 3 3 3
Total 57 57 46
savings (from cooling) to be the four most commonly reported, with noise reduction, biodiversity/habitat creation and flood ame-lioration being lesser reported ones (Royetal.,2012).Treesare alsobetterfor increasingthespecies richnessat highertrophic levelsofecosystemsi.e.invertebrates(Smithetal.,2006).Inthis respect,Pozna ´nAGsoutperformManchesterAGsinthese ecosys-temservicesbecausenon-edibletreesaregenerallyabsent,orofa smallsize,onManchesterallotmentsinordertoreduceshadeand maximisevegetableyield.Thishasconsequentdifferencesinthe regulatingservicesprovidedbythelanduses.
AGlandusetendstobeahighlyheterogeneousmosaicof differ-entvegetationtypeswithsome‘wild’areas.Overgrown,abandoned landwasverycommononManchesterAGs.Thisprovides oppor-tunitiessuchasforagingfor wildfoods(wild blackberrieswere common) and is a starkcontrast to theintensive monoculture of modernagriculturalpractices.Industrial crop productionhas beenfoundtobeatoddswithregulatingservicesattheEuropean regionalscale(Maesetal.,2012)butAGsoffertheseregulating services,albeitatasmallerscale.Forexample,topsoilsofUK allot-mentswerefoundtobehigherin soilorganiccarbon andtotal nitrogenandlowerinbulkdensitythanconventionalagricultural fields(Edmondsonetal.,2014).Smallscaleurbanfoodproduction canoccurwithoutthesoildegradationcommontoconventional agriculturethuspreservingregulatingecosystemservicessuchas carbon storage,nutrient cycling, water purificationand climate regulation(Edmondsonetal.,2014).
Support of pollinators is increasingly important given the reporteddeclineofpollinatorssuchasbees,andthepotentially disastrousconsequencesthiswillhaveuponcrops(Goulsonetal., 2008).AGs inSweden werefound tobeimportant alternatives toruralhabitatsforbee populations,albeitwithvariable abun-dancedataforcertainspecies.Managementpractices,suchasthe presenceofnativeflowers,stronglyaffectabundanceandspecies composition(Ahrnéetal.,2009).Allotmenttenantsare increas-inglyawareofthebenefitsofattractingpollinatorinsectsandthe pastfewyearshasseenmorehigh-nectarflowers,suchasPhacelia
tanacetifoliaandTrifoliumpratensis,beingplantedalongside veg-etables. Some allotment holders grow heritage and heirloom varietiesofvegetables,asopposedtoengineeredhybrids,andthis canbeaninvaluableprovisioningecosystemservicebyimparting geneticdiversity(NaturalEngland,2007).
Itisworthnotingthatmanyoftheadditionalecosystemservices beyondfoodproduction, providedby AGs,have spatialimpacts beyondtheconfinesofthegardens.Localclimateregulation,flood protectionandairqualityregulationwillespeciallybenefitalarge numberoflocalresidentsincitiesattheneighbourhoodscale.
Thesocial aspects ofurban vegetation areoften overlooked inresearch (Royet al., 2012). A study in the Netherlands sug-gestedthat elderlyallotmentholders enjoygreaterhealth than theirneighbourswhodonotownanallotmentduetothe main-tenanceofanactivelifestyle(VandenBergetal.,2010).AGsactas acollectivesocial-ecologicalmemory-preservingsite(Bartheletal., 2010)whichisimportantincitiesbecauseurbandwellerswhodo notexperiencenaturefirst-handearlyandregularlyarelesslikely tobemotivatedtobecomestewardsofecosystemserviceslater (Rosenzweig,2003).
UrbanAGpopularitytendstoincreaseintimesofhardship,such asduringwartime,byprovidingfoodsecurity.Arecentexampleis thereductionofSovietaidandtradeinCubapromptingthe explo-sionofurbangardensinHavana(Moskow,1999).Climatechange mayposeanewformofthreattofoodsecuritybyincreasingthe frequencyofextremeweatherevents.Thereisapotential there-foreforAGs,andtheirregulatingecosystemservices,tohelpwith climatechangeadaptationandmitigation(Lwasaetal.,2014).
AGsintheUKarerecognisedbythegovernmentasvaluable communityspaceswithmultiplebenefits,andtherearelegaland policysafeguardsinplacetoensurelocalauthoritiescannotsell orappropriateAGswithouttheconsentoftheSecretaryofState (DCLG,2014).Inordertomeetthecriteriaofsection8ofthe Allot-mentsAct1925,thecouncilmust make adequateprovisionfor displacedplotholders.Nonetheless,theNationalAllotment Soci-etyoftheUKisreceivingincreasingnumbersofcallsfromworried tenantswhofeelthatthelandisunderthreatfromdevelopment (NAS,2014).Aproblemcouldbethatallotmentsfailtoconform totheidealofprivate,individualisedspaceandconventional dis-coursesonmunicipalrecreationandleisure(CrouchandWard, 1997;DeSilvey,2003).Solutionsaretorecognisetheimportance ofAGsasabeneficialurbanlandusetypewithinlocalgovernment policiesandtopromotetheirbenefitstocitizens.Benefits,asthis paperhasshown,gobeyondconceptsofcommunityfoodsecurity andputAGsfirmlywithindiscussionsonsustainabledevelopment, biodiversityandsocialcohesion.
Conclusion
AGsprovideawiderangeofecosystemservicesinurbanareas. Servicesrelated to pollination,food provision,biodiversity and recreationrankveryhighlyonAGs.In particularthey providea numberofecosystemservicesthathavegreatimportanceincities duetothehighdensityofresidents,trafficandimperviousbuilt surfaces.Theseincludelocalclimateregulation,noisereduction, airfilteringandrecreation.Theyofferlocalauthoritiesthe poten-tialtointerveneintrickytomanageecosystemservicessuchas pollinationandsoilformationbysimplyprovidingasourcearea withnoneedforadvancedtechnologies(Bernaciak,2012).They alsooffermultipleecosystemserviceswithfewertrade-offsthan otheragriculturallanduses(Rodriguezetal.,2006).
TheAGs in this study scoredhighly onseveral provisioning andregulatingservicesasaresultofthetype,diversityand dis-tribution of the vegetation. Cultural services were also highly apparentasAGsofferurbanresidentsachancetosocialise,share
knowledge,andconnectwithnature.Differencesbetweenthetwo AGtypologieswerenoted,withfewertreesonManchester allot-mentsduetoaculturalpreferenceforvegetablegrowing.Urban parks,incomparisontoAGs,canbeenjoyedbyagreaternumber ofcityresidentsandhavemore,andtaller,treeswithassociated ecosystemservices.Parks,however,lackthespeciesrichnessofAGs andalsodonotscorewellwithinprovisioningecosystemservices. SomesuggestionsforimprovementsonAGsinclude:Strategic plantingoftreesonManchesterallotmentstoprovideshadefora futurewarmerclimate;increasetheamountofwatercapturefrom imperviousroofsurfacesforirrigationuses;promotionofholistic, organicgardeningpractices;installbeehivesandnon-ornamental ponds;andincreasepublicinteractiononallotments.
Theresultsofthisstudysuggestthattheremaybeaneedfor moreformalrecognitionofecosystemserviceprovisionbyAGsin localgovernmentpolicyin theEuropean Union.Allotment ten-antsarelocalstewardsof urbangreenspaceand thusservean importantrolein protectionof biodiversityand climate change adaptation,whicharecommonly-citedgoalsoflocalgovernment. Locally-managed,non-protectedgreenspacescanspatially domi-natecitiescomparedtoprotectedonessuchasnaturereservesand greenbelt.Greenareasmanagedbylocalusergroupsmayplayan increasinglycriticalroleinthefuturefunctioningandresilienceof urbanecosystems(Coldingetal.,2006).
Acknowledgements
ThePolandresearchwasfundedbytheEuropeanCooperation inScienceandTechnology(EUCOST)ActionTU1201—‘Urban Allot-mentGardens’.Thankyoualltheallotmentgardentenantswho welcomedtheresearchersontotheirplotsoverthesummer. AppendixA. Supplementarydata
Supplementarymaterialrelatedtothisarticlecanbefound,in theonlineversion,atdoi:10.1016j–1.ufug.2015.07.007.
References
Ahrné,K.,Bengtsson,J.,Elmqvist,T.,2009.Bumblebees(Bombusspp.)alonga gradientofincreasingurbanization.PLoSONE4(5),e5574.
Alberti,M.,Marzluff,J.M.,2004.Ecologicalresilienceinurbanecosystems:linking urbanpatternstohumanandecologicalfunctions.UrbanEcosyst.7,241–265.
Barthel,S.,Folke,C.,Colding,J.,2010.Social–ecologicalmemoryinurban gardens—retainingthecapacityformanagementofecosystemservices.Global Environ.Change20,255–265.
Barthel,S.,Isendahl,C.,2013.Urbangardens,agriculture,andwatermanagement: sourcesofresilienceforlong-termfoodsecurityincities.Ecol.Econ.86, 215–225.
Bellows,A.,2004.OnehundredyearsofallotmentgardensinPoland.Food Foodways12,247–276.
Bernaciak,A.,2012.Theroleoflocalauthoritiesinthemanagementandprotection ofecosystemservices.Ekon. ´Srodowisko2(42),74–82.
Bolund,P.,Hunhammar,S.,1999.Ecosystemservicesinurbanareas.Ecol.Econ.29, 293–301.
Borysiak,J.,Mazurek,M.,Zwoli ´nski,Z.,2014.Landcoverandecosystemservices changesinagriculturallandscapesoftheD ˛ebnicacatchment(WestPomerania, Poland).Ekon. ´Srodowisko4(51),205–220.
BundesverbandDeutscherGartenfreunde(BDG),2008.Artenvielfalt.Biodivers. KulturpflanzenKleingärten(Berlin),64.
Burkhard,B.,Kroll,F.,Nedkov,S.,Müller,F.,2012.Mappingecosystemservice supply,demandandbudgets.Ecol.Indicat.21,17–29.
Cheffings,C.M.,Farrell,L.(Eds.),2005.TheVascularPlantRedDataListforGreat Britain.SpeciesStatus,vol.7.JointNatureConservationCommittee, Peterborough,pp.1–116.
Colding,J.,Lundberg,J.,Folke,C.,2006.Incorporatinggreen-areausergroupsin urbanecosystemmanagement.AMBIO35(5),237–244.
Costanza,R.,d’Arge,R.,DeGroot,R.,Farber,S.,Grasso,M.,etal.,1997.Thevalueof theworld’secosystemservicesandnaturalcapital.Nature387,253–260.
Costanza,R.,Kubiszewski,I.,2012.Theauthorshipstructureof“ecosystem services”asatransdisciplinaryfieldofscholarship.Ecosyst.Services1,16–25.
Cousens,R.,Mortimer,M.,1995.DynamicsofWeedPopulations.Cambridge UniversityPress.
Crouch,D.,Ward,C.,1997.TheAllotment.ItsLandscapeandCulture.FiveLeaves Publications,Nottingham,UK.
Crowe,T.M.,1979.Lotsofweeds:Insularphytogeographyofvacanturbanlots.J. Biogeogr.6(2),169–181.
CSOP,2014.CentralStatisticalOfficeofPolandwebsite.Availableathttp://stat.gov. pl/en/
DCLG,2014.DepartmentforCommunitiesandLocalGovernmentReport: Allotmentdisposalguidance:Safeguardsandalternatives.Availableatwww. gov.uk/dclg
DeBello,F.,Lavorel,S.,Dı´ıaz,S.,Harrington,R.,Bardgett,R.,Berg,M.,etal.,2010.
Functionaltraitsunderliethedeliveryofecosystemservicesacrossdifferent trophiclevels.Biodivers.Conserv.143,2873–2893.
DeGroot,R.S.,Alkemade,R.,Braat,L.,Hein,L.,Willemen,L.,2010.Challengesin integratingtheconceptofecosystemservicesandvaluesinlandscape planning,managementanddecisionmaking.Ecol.Complex.7,260– 272.
DeSilvey,C.,2003.CultivatedhistoriesinaScottishallotmentgarden.Cultur. Geogr.10,442–468.
Edmondson,J.L.,Davies,Z.G.,Gaston,K.J.,Leake,J.R.,2014.Urbancultivationin allotmentsmaintainssoilqualitiesadverselyaffectedbyconventional agriculture.J.Appl.Ecol.51,880–889.
EnvironmentAgency,2013.ManagingJapaneseKnotweedondevelopmentsites. Availableatwww.environment-agency.gov.uk
Gómez-Baggethun,E.,Barton,D.N.,2013.Classifyingandvaluingecosystem servicesforurbanplanning.Ecol.Econ.86,235–245.
Goulson,D.,Lye,G.C.,Darvill,B.,2008.Declineandconservationofbees.Annu.Rev. Entomol.53,191–208.
Grime,J.P.,1977.Evidencefortheexistenceofthreeprimarystrategiesinplants anditsrelevancetoecologicalandevolutionarytheory.Am.Naturalist111, 1169–1194.
Grime,J.P.,1998.Benefitsofplantdiversitytoecosystems:immediate,filterand foundereffects.J.Ecol.86,902–910.
Guitart,D.,Pickering,C.,Byrne,J.,2012.Pastresultsandfuturedirectionsinurban communitygardensresearch.UrbanForestryUrbanGreen.11,364–373.
Haigh,M.J.,1980.RuderalcommunitiesinEnglishcities.UrbanEcol.4, 329–338.
Haines-Young,R.,Potschin,M.,2008.England’sTerrestrialEcosystemServicesand theRationaleforanEcosystemApproach.,pp.30pp,Overviewreport(Defra ProjectCodeNR0107).
Harrap,S.,2013.WildFlowers.AFieldGuidetotheWildFlowersofBritainand Ireland.BloomsburyPublishing,London.
Loram,A.,Thompson,K.,Warren,P.H.,Gaston,K.J.,2008.Urbandomesticgardens (XII):therichnessandcompositionoftheflorainfivecities.J.Vegetat.Sci.19, 321–330.
Lwasa,S.,Mugagga,F.,Wahab,B.,Simon,D.,Connors,J.,Griffith,C.,2014.Urban andperi-urbanagricultureandforestry:transcendingpovertyalleviationto climatechangemitigationandadaptation.UrbanClimate7,92–
106.
Maes,J.,Paracchini,M.L.,Zulian,G.,Dunbar,M.B.,Alkemade,R.,2012.Synergies andtrade-offsbetweenecosystemservicesupply,biodiversity,andhabitat conservationstatusinEurope.Biol.Conserv.155,1–12.
Maes,J.,Teller,A.,Erhard,M.,Murphy,P.,Paracchini,M.L.,etal.,2014.Mapping andassessmentofecosystemsandtheirservices.Indicatorsforecosystem assessmentunderAction5oftheEUBiodiversityStrategyto2020. PublicationsOfficeoftheEU,Luxembourg.
Mobbs,P.,2002.Growyourownfood—freerangepracticeguide5.FRPG-05/1. Availableathttp://www.networkforclimateaction.org.uk/toolkit/positive alternatives/foodandfarming/growyourownfood.pdf
Moskow,A.,1999.Havana’sself-provisiongardens.Environ.Urban.11(2), 127–134.
NAS,2014.NationalAllotmentSociety.Protectyourplots.http://www.nsalg.org. uk/news-events-campaigns/protect-your-plots/
NaturalEngland,2007.WildlifeonAllotments.Availableathttp://www.nsalg.org. uk/resources-and-downloads/associations-societies-and-federations/
Pauleit,S.,Ennos,R.,Golding,Y.,2005.Modelingtheenvironmentalimpactsof urbanlanduseandlandcoverchange—astudyinMerseyside,UK.Landscape UrbanPlann.71,295–310.
Preston,C.D.,Pearman,D.A.,Dines,T.D.(Eds.),2002.NewatlasoftheBritishand Irishflora.OxfordUniversityPress,Oxford.
Pyˆsek,P.,1995.Ontheterminologyusedinplantinvasionstudies.In:Pyˆsek,P., Prach,K.,Rejmánek,M.,Wade,M.(Eds.),PlantInvasions:GeneralAspectsand SpecialProblems.SPBAcademicPublishing,Amsterdam,pp.71–81.
PZD,2014.PolskiZwi ˛azekDziałkowców.Availableathttp://pzd.pl/artykuly/ 13173/168/Allotment-gardens-in-the-cities-nowadays-and-in-the-future-challenges-and-functions.html
Rodriguez,J.P.,BeardJr.,T.D.,Bennett,E.M.,Cumming,G.S.,Cork,S.J.,Agard,J., Dobson,A.P.,Peterson,G.D.,2006.Tradeoffsacrossspace,time,andecosystem services.Ecol.Soc.11,28.
Rosenzweig,M.L.,2003.Win-WinEcology:HowtheEarth’sSpeciesCanSurvivein theMidstofHumanEnterprise.OxfordUniversityPress,UK.
Roy,S.,Byrne,J.,Pickering,C.,2012.Asystematicquantitativereviewofurbantree benefits,costs,andassessmentmethodsacrosscitiesindifferentclimatic zones.UrbanForestryUrbanGreen.11,351–363.
Smith,R.M.,Gaston,K.J.,Warren,P.H.,Thompson,K.,2006.Urbandomestic gardens(VIII):environmentalcorrelatesofinvertebrateabundance.Biodivers. Conserv.15,2515–2545.
Sustain,2014.ReapingRewards.CanCommunitiesGrowaMillionMealsfor London?ASustainPublication.Availableatwww.capitalgrowth.org
Tokarska–Guzik,B.,2005.Theestablishmentandspreadofalienplantspecies (kenophytes)inthefloraofPoland.Pr.Nauk.U ´S.2372,Katowice.
UKstatistics,2014.UKPopulationstructurestatistics.Availableathttp://www. neighbourhood.statistics.gov.uk/HTMLDocs/dvc134a/index.html
VandenBerg,A.E.,Winsum-Westra,M.v.,DeVries,S.,VanDillen,S.,2010.
Allotmentgardeningandhealth:acomparativesurveyamongallotment gardenersandtheirneighbourswithoutanallotment.Environ.Health9,74.
Zarzycki,K.,Trzci ´nska–Tacik,H.,Ró ˙za ´nski,W.,Szel ˛ag,Z.,Wołek,J.,Korzeniak,U., 2002.EcologicalIndicatorValuesofVascularPlantsofPoland.W.Szafer InstituteofBotany,PolishAcademyofSciences,Kraków.
