Ecology/E´cologie
Conservation of Mediterranean wetlands: Interest of historical approach
Conservation des zones humides me´diterrane´ennes : inte´reˆt de l’approche historique AminaDaoud-Bouattoura,b,*,Serge D.Mullerc,Hafawa Ferchichi-BenJamaaa,b,c,
SamiaBen Saad-Limama,b,Laı¨la Rhazid,Ingeborg Soulie´-Ma¨rschec,MayaRouissia,b, BesmaTouatia,b, Imtine`neBen HajJilanib,e,AmorMokhtar Gammarb,
ZeinebGhrabi-Gammarb,e
aDe´partementdebiologie,faculte´ dessciencesdeTunis,universite´ deTunisElManar,campusleBelve´de`re,2092Tunis,Tunisia
bURbioge´ographie,climatologieapplique´eetdynamiquee´rosive,faculte´ deslettres,desartsetdeshumanite´sdeManouba,universite´ delaManouba, campusuniversitairedelaManouba,2010Manouba,Tunisia
cUniversite´ Montpellier-2/CNRS,institutdessciencesdel’e´volutiondeMontpellier(ISE-M),case061,34095Montpelliercedex05,France
dLaboratoired’e´cologieaquatiqueetenvironnement,faculte´ dessciences,universite´ HassanIIAı¨nChock,BP5366,Maarif,Casablanca,Morocco
eInstitutnationalagronomiquedeTunisie,43,avenueCharles-Nicolle,1082,cite´ Mahraje`ne,Tunis,Tunisia C.R.Biologies334(2011)742–756
ARTICLE INFO
Articlehistory:
Received27May2011
Acceptedafterrevision14July2011 Availableonline24August2011
Keywords:
Acidicfreshwater Biodiversity Historicalecology Humandisturbances Hydrophyticvegetation NorthAfrica
Palaeoecology
Motscle´s: Eauxdoucesacides Biodiversite´
E´cologiehistorique Perturbationsanthropiques Ve´ge´tationhydrophytique AfriqueduNord Pale´oe´cologie
ABSTRACT
ThewetlandsofNorthAfricaareanendangeredandinvaluableecologicalheritage.Someof thesewetlandsarenowprotectedbyvariousconservationstatutes;whichactualimpacthas notyetbeenreliablyevaluated.Thisarticleaimstoassesstheconservationmanagement (NatureReserveandRamsarsite)ofaprotectedTunisianlake,MajenChitane,byusing palaeoecological,historicalandmoderndata,andbycomparingitwiththeunprotectedlake MajenChoucha.Whilelocatedinsimilarenvironments,theselakesaretodayhometovery differentflora.Baselineconditionsreconstructedfromliteratureindicatethatbothlakes wereverysimilaruntilthe1950s,andcomparabletothecurrentstateofMajenChoucha, housingricholigotrophicplantcommunities.Inthe1960s,atthetimethatcultivationofthe adjacentpeatlandbegan,MajenChitaneunderwentstrongecologicalchangesastheinitial oligotrophicplant,diatomandzooplanktoncommunitieswerereplacedbyeutrophication- tolerantones.Eutrophicationledtothelocalextinctionof40–55%ofthehydrophyticand temporary-poolplantspecies, includingthosecharacteristicof theIsoetion.Giventhe damagesanddespitetherecentconservationstatusofthesite,it’sunlikelythatMajen Chitanewillundergoanynaturalregeneration.Restoringitwouldstartwithcompletely protectingthecomplexlake-peatlandandre-introducingthelocallyextinctspeciesfrom Majen Choucha.This work exemplifies theusefulness of connecting palaeoecological, historicalandmoderndatafortheconservationofMediterraneanwetlands.
ß2011Acade´miedessciences.PublishedbyElsevierMassonSAS.Allrightsreserved.
RE´ SUME´
Leszoneshumidesd’AfriqueduNordrepre´sententunpatrimoinee´cologiqueinestimable etmenace´.Certainessontaujourd’huiprote´ge´espardiversstatutsdeconservation,dont l’impactre´eln’apasencoree´te´ e´value´ demanie`refiable.Cetarticlevisea` e´valuerlagestion conservatoire(Re´serveNaturelleetsiteRamsar)d’unlactunisienprote´ge´ (MajenChitane), a` traversdesdonne´espale´oe´cologiques,historiquesetactuelles,parcomparaisona` unlac nonprote´ge´ (MajenChoucha).Bienquesitue´sdansdesenvironnementssimilaires,ces deuxlacshe´bergentaujourd’huidesflorestre`sdiffe´rentes.Lareconstructiondel’e´tatde
*Correspondingauthor.
E-mailaddress:daoudamina200@yahoo.fr(A.Daoud-Bouattour).
ContentslistsavailableatScienceDirect
Comptes Rendus Biologies
ww w . sci e nc e di r e ct . com
1631-0691/$–seefrontmatterß2011Acade´miedessciences.PublishedbyElsevierMassonSAS.Allrightsreserved.
doi:10.1016/j.crvi.2011.07.006
1. Introduction
The Mediterraneanregion includes diversified wet- lands [1,2] with high ecological [3,4], economic and social values [5]. Temporary wetlands in particular house a rare and endangered flora, which lend them an especially high conservation value [6–9]. These contribute greatly to regional biodiversities, and both their importance and vulnerability helped to identify several hotspots [3,10,11]. Temporary wetlands, abun- dantmainlyonthesouthernsideoftheMediterranean, are rapidlydeclining[12–16] becauseof stronghuman pressure [17–21]. To ensure the durability of these unique and endangeredecosystems, several inventory, assessmentandmonitoringprogramshavebeenimple- mentedon Mediterranean wetlands(e.g. [22–25]),and Maghreb countries have recently developed various wetland-conservationmeasuresandinitiatives(National Parks,NatureReservesandRamsarsites).However,only a fewstudies focus on evaluating the impact of these conservation measures. For instance, the MELMARINA project aimed to establish integrated hydrologicaland ecological monitoring of North African coastallagoons [26],theCASSARINAprojectassessedthecurrentstateof twelve NorthAfricanlakesbymakingbiologicalinven- toriesandreconstructingtheirrecentdynamics[27],and theIchkeulNationalParkundergoesaregularmonitor- ing ofitsmarshandlakehabitats [28–33].
InTunisia,withtheexceptionofIchkeulNationalPark, onlyonesemi-permanentlake, MajenChitane,hasbeen protectedsince1993.Thelakeandadjacentpeatland(Dar el Orbi) have been studied repeatedly since the 1950s [27,34–39],butnosynthesisoftheseworkshaseverbeen published.TheCASSARINAprojectemphasizedthemajor interestofthissite forconservation[27],but theearlier works of Pottier-Alapetite & Labbe [34] and Pottier- Alapetite [35] were not considered. Moreover, Majen Choucha, another Tunisiansemi-permanent lake that is relatively similar to Majen Chitane [21,35], is not yet protected.Acomparisonofthesetwositestakenwiththe synthesisofpreviousstudiesprovidesauniqueopportu- nitytomakeanhistoricalevaluationoftheconservation valueofbothwetlandsandthepertinenceofthecurrent conservationmeasures[40].
In recent years, palaeoecological and historical data havebeenusedincreasinglyfordefiningbaselinecondi- tionsof ecosystems,in ordertoassesstheamplitudeof theirnatural variability,theirnaturalness,their fragility, andtheconservationstatus ofrarespecies [41–44].The needtoconnectecological,palaeoecologicalandhistorical datahasbeenhighlightedsincethe1990s[45–51].Such interdisciplinaryapproachesoffertheoreticalandapplied perspectives:theyareparticularlypertinentfor abetter comprehension of ecosystem functioning and they can helptorefineconservationmanagementpolicies[45,50–
52].However,theyarenotoftenusedandareoftenignored by scientists and managers [53]. This paperdocuments local ecological changes of Majen Choucha and Majen Chitanebycomparingancientandrecentphytosociologi- calreleve´sandbyusingthepalaeoecologicaldataavailable in the literature to: (1) evaluate the changes having affectedMajenChitaneandMajenChouchaLakes,and(2) assessanddiscussthecurrentconservationmanagement ofMajenChitaneLake.Thisworkattemptstodemonstrate theusefulness andtheneedofinterconnecting palaeoe- cological,historicalandmoderndatafortheconservation ofMediterraneanwetlands.
2. Studysites
ThetermsusedforNorthAfricawetlandsvarygreatly, dependingon regionsand countries.The termdaya,for example,specificallyreferstoaMoroccantemporarypool [9], whereas in Tunisia, garaˆa (or garaˆet) designates a lowland lake, and majen (alternatively madjen, megene, majinorMajel),asmallmountainlake[54].Addingtothe varietyoflocalterminologies,changesormistakesabout thenamesofcertainsitesarenotrareintheliterature,and maycreatefurther confusion.Thishasbeentrueforthe studiescarriedoutonMajenChitaneLake,whichhasbeen namedLacdesNe´nuphars[35,55],MajenelOrbi[39],and GaaˆretSejnane [38]. Thislast nameis definitelywrong, sinceGaraˆaSejenaneisthelargealluvialplainclosetothe cityofSejenane[16](Fig.1).
MajenChitaneandMajenChouchaLakes(Fig.1;Table 1)are locatedin thesandstone OligoceneMogods Hills (northern Tunisia) and are separated by approximately 20km.Thisregion,withanannualrainfallbetween800to re´fe´rencea` partirdesdonne´esdelalitte´raturere´ve`lequelesdeuxsitese´taienttre`s similairesavantlesanne´es1950,etcomparablesa` l’e´tatactueldeMajenChoucha:ils he´bergeaient notammentde richescommunaute´s ve´ge´talesoligotrophes.Depuisles anne´es1960,simultane´menta` lamiseenculturedelatourbie`readjacente,MajenChitane connaıˆt des changements e´cologiques profonds marque´s par le remplacement des communaute´soligotrophesinitialesdeplantes,dediatome´esetdezooplancton,pardes communaute´stole´rantesa` l’enrichissementdumilieu.L’eutrophisationdulacaentraıˆne´
l’extinctionlocalede40–55%d’hydrophytesetdeplantescaracte´ristiquesdesmares temporaires,ycomprisdesespe`cesdel’Isoetion.Comptetenudesdommagessubispar MajenChitaneetende´pitdesmesuresdeprotectionquionte´te´ prises,sare´ge´ne´ration naturellenesemblepasre´aliste.Sarestaurationimpliquelamiseende´fensdetoutle complexelac-tourbie`reet lare´introduction,a` partirde MajenChoucha,des espe`ces localement e´teintes.Ce travailmet en exerguel’inte´reˆt de l’utilisationinte´gre´edes donne´es pale´oe´cologiques, historiques et actuelles pour la conservation des zones humidesme´diterrane´ennes.
ß2011Acade´miedessciences.Publie´ parElsevierMassonSAS.Tousdroitsre´serve´s.
A.Daoud-Bouattouretal./C.R.Biologies334(2011)742–756 743
1000mm, is one of the rainiest in Tunisia, and has a Numidianflyshsubstratum[56].ItpresentsaMediterranean wet bioclimate, with hot winters on the coast (Majen ChitaneLake),andmildwintersinland(MajenChouchaLake) [57]. The regional vegetation is dominated by degraded thermo-Mediterranean cork-oak forests and scrub, with Calicotome villosa, Erica arborea, Myrtus communis, Phillyrealatifolia,PistacialentiscusandQuercuscoccifera.
Majen Chitane is a small (1.5ha), semi-permanent (drying out during the driest years), freshwater, acidic, shallow (185cm deep) lake located near the coast (3780901000N, 0980505300E; 150m; Fig. 1) on a clayey depressionofthenorthernslopeofasandstonereliefcalled Jbel Chitane that rises to 454m (Fig. 2A). It is fed by rainwaterand bythreesmallfreshwater springs,twoof which are permanent and trickle down through a Pteridiumaquilinumpeatland(DarelOrbi;Fig.2A)located 50maboveandalmostfullycultivated(fruittrees,peppers, potatoes,tobacco...).Thethirdstreamdoesnotcrossthe peatlandanddriesupinsummer[58].Thespringwateris pumpedfromlatespringthroughsummertoirrigatethe cultivatedpart ofthepeatland. Since1993,the lakeand surroundingforest(5ha)havebeenfencedandprotectedas a Nature Reserve. In 2007, the complex lake-peatland becamea Ramsar site; however, the peatland, which is privatelyowned,isstillcultivatedtoday[59].
Majen Choucha is a similar, small (0.5ha), shallow (100cm deep) semi-permanent freshwater acidic lake locatedonthesouthernedgeofMogodsHills,onaclayey depression on the top of the sandstone massif of Jbel Choucha thatrises to513m(3780003800N, 0981204200E;
445m,Figs.1and2B).Surroundedbyanovergrazedcork- oakforest,thelakeisisolatedontheJbelChouchamassif, and difficulttoaccess,although cattle,sheep and goats
regularlypassaroundit,andthelocalpopulationusesitto gathertheleechesthataboundfromspringtosummer.
3. Materialsandmethods
3.1. Currentvegetation
Weundertookfloristicinventoriesfrom2006to2010 atMajenChitaneLakeandfrom2008to2011atMajen Choucha Lake. We constructed maps of the current vegetationforbothlakes.Phytosociologicalreleve´swere carried out in the three vegetation belts (central, intermediate and marginal) of Majen Chitane (June 2010)andMajenChoucha(April2008)Lakes usingthe Braun-Blanquet[60]method,withanabundance/domi- nancescalefrom+to5.Wecomparedthemwithdatathat hadbeencollectedonbothlakesinMayandJune1951by Pottier-Alapetite and Labbe [34] and Pottier-Alapetite [35]. Wedistinguish belowthetemporary-pool species (amphibiousspecies)characteristicoftemporaryhabitats from the hydrophytic species (aquatic and helophytic species) characteristic of permanent waters. Plant no- menclaturefollowsLeFloc’hetal.[61].Acorrespondence analysiswasperformed(STATOSprogram,[62])onthe abundances of62speciesoftheexternalbelts (=inter- mediate+marginal belts) of Majen Chitane Lake (May 1951andJune2010)andMajenChouchaLake(June1951 andApril2008).WeexcludedMyriophyllumalterniflorum, SchoenoplectuslacustrisandSparganiumerectum,fromthis analysisbecausetheyarenotincludedinthephytosocio- logical releve´s of Pottier-Alapetite andLabbe [34] and Pottier-Alapetite [35] while they were inventoried by these authors. We also excluded Nitella opaca and Fig.1. Locationofthetwostudiedsemi-permanentlakes(Mogodsregion,northernTunisia).MChi,MajenChitane;MCho,MajenChoucha.
A.Daoud-Bouattouretal./C.R.Biologies334(2011)742–756 744
N.translucens(Charophytes),becausetheseauthorsdid notconsiderthem.
3.2. DiachronicanalysisofMajenChitane
A spatial analysis was conducted from stereoscopic observationofaerialphotographs(1948,1963and1989;
OfficedelaTopographieetdelaCartographie,Tunis),anda GoogleEarthimage(2007;GoogleEarth,2010).Mapsof thevegetationin1951and1997–98mapswerereported from[34,63].Thesynthesis ofprevious palaeoecological
studies[27,37–39,64–68]isusedtoreconstructlong-term localecologicaldynamics.
4. Results
4.1. Vegetation
Phytosociological releve´s and floristic inventories carried outin 1951 [30,31]and 2006-2011(this study) inbothlakes,identified83species(63atMajenChitane Fig.2.Semi-permanentfreshwateracidiclakesinTunisia.A,MajenChitaneLake,largelycoveredbyNymphaeaalba,overhungbythecultivatedDarelOrbi peatland(arrow)(S.D.Muller,July2008).B,MajenChouchaLake,surroundedbyagrazedcork-oakforest(A.Ruhı´,April2010).
Table1
Characteristicsofthestudiedsitesanddatesoffloristicsurveys.
MajenChitaneLake MajenChouchaLake
Code MChi MCho
LatitudeN 378090100 0 378000380 0
LongitudeE 098050530 0 098120420 0
Altitude(m) 150 445
Maximumdepth(cm) 185 100
Area(ha) 1.5 0.5
Currentconservationmeasure NatureReserve(1993)
Ramsarsite(2007) None
Dateofphytosociologicalreleve´s May1951[34,35]June2010(thisstudy) June1951[35]April2008(thisstudy)
Dateoffloristicinventories May,June,July2006–2010(thisstudy) February,April,May,JulyandDecember2008–2011(thisstudy)
A.Daoud-Bouattouretal./C.R.Biologies334(2011)742–756 745
Table 2
Floristic inventories and phytosociological releve´s realized on the studied sites in 1951[34,35], in 2006–2010 at Majen Chitane Lake (this study; May, June and July), and in 2008–2011 at Majen Choucha Lake (this study; February, April, May, July and December).
Phytosociological releve´s (external belt)
Floristic inventories
Majen Chitane
Majen Choucha
Majen Chitane
Majen Choucha
Taxon Synonym(s) Code Ecology Statut May 1951 June
2010 June 1951
April 2008
May 1951
2006–2010 June 1951
2008–2011
Agrostis pourretiiWilld. A. salmantica,A. pallida Agpo P + E
Alisma lanceolatumWith. A. plantago, A. plantago-aquatica Alla H + M M,I
Alopecurus bulbosusGouan Albu 1 + E E M
Anagallis arvensisL. Anar + M M
Baldellia ranunculoides(L.) Parl.a Alisma ranunculoides, Echinodorus ranunculoides
Bara P RR-NT 1 1 + E M,I E
Bellis annuaL. M
Bellis prostrataPomel B. repens,B. radicans Bepr IF-NT 1 E M
Bolboschoenus glaucus(Lam.) S.G. Smith B. maritimus,Scirpus maritimus Bogl H + 1 E I I
Callitriche brutiaPetagna C. palustrissubsp.pedunculata Cabr P 1.2 1 I,C M,I
Callitriche obtusangulaLe Gall Caob H 1 1 + 1 E M,I E M,I,C
Carex divulsaStokes subsp.divulsa Cadi + M
Carex flaccaSchreb.subsp.
serrulata(Biv.) Greuter
C. flaccasubsp.erythrostachys Cafl + M
Chara connivensSalzmann H RR C
Corrigiola litoralisL. Coli + M M
Cotula coronopifoliaL. Coco H 2 + M,I M
Cynodon dactylon(L.) Pers. Cyda 1 + M E M
Cynosurus polybracteatusPoir. C. cristatus Cypo 1 M
Cyperus longusL. subsp.badius (Desf.) Bonnier & Layens
Cylo H 1 M,I
Damasonium bourgaeiCoss. D. alismasubsp.bourgaei Dabo P + M
Elatine alsinastrumL. Elal H RR-CR + 1 E M,I,C
Eleocharis multicaulis(Sm.) Desv. Elmu H RR-NT + M
Eleocharis palustris(L.) Roem. & Schult. Scirpus palustris Elpa H 1 1 E M,I M,I
Eryngium pusillumL. E. barrelieri Erpu P 1 + + E E M
Euphorbia chamaesyceL. M
Exaculum pusillum(Lam.) Caruel P RR-NT M
Filago pygmaeaL. Evax pygmaea M
Galactites tomentosaMoench G. elegans Gato + M M
Galium palustreL. subsp. elongatum (C.Presl) Lange
G. elongatum Gapa H + + E M
Glyceria spicata(Biv.) Guss. G. fluitanssubsp.spicata Glsp H 1 1 2 E E-C M,I,C
Helosciadium crassipesW.D.J. Koch ex Rchb. Apium crassipes Hecr P IF-NT + 4 E-C M,I
Illecebrum verticillatumL. Ilve P IF-LC 1 3 1 E E M,I
Isoetes velataA.Braun Isve P IF-LC 3 1 + 4 E M,I E M,I
Isolepis cernua(Vahl.) Roemer & Schultes Scirpus savii,S. cernuus Isce + + E M M
Juncus acutusL. Juac 1 M,I
Juncus ancepsLaharpe Juan 1 M
Juncus articulatusL. Juar H 1 M
Juncus bufoniusL. J. bufoniussubsp.eu-bufonius Jubu 1 E M
Juncus capitatusWeigel Juca + E
Juncus conglomeratusL. Juco 1 M
A.Daoud-Bouattouretal./C.R.Biologies334(2011)742–756746
Table 2 (Continued)
Phytosociological releve´s (external belt)
Floristic inventories
Majen Chitane
Majen Choucha
Majen Chitane
Majen Choucha
Taxon Synonym(s) Code Ecology Statut May 1951 June
2010 June 1951
April 2008
May 1951
2006–2010 June 1951
2008–2011
Juncus effususL. Juef + M
Juncus heterophyllusDufour Juhe H 1 + 1 C I E M,I
Juncus pygmaeusRich. ex Thuill. Jupy IF-LC + M
Kickxia commutata(Reichenb.) Fritsch Linaria commutata Kico P 1 M
Lotus angustissimusL. subsp.angustissimus L. palustris Loan P + + E
Lotus hispidusDesf. ex DC. L. angustissimus
subsp.hispidus
Lohi 1 + M M
Lythrum borysthenicum(Schrank) Litv. L. nummularifolium, L. hispidulum
Lybo P R-LC 1 1 1 M E M
Lythrum hyssopifoliaL. Lyhy 1 1 + E M E M
Lythrum junceumBanks & Sol. Lyju 1 M M
Lythrum portula(L.) D.A. Webb Peplis portula Lypo H 1 + 1 I E M,I
Lythrum tribracteatumSalzm. ex Spreng. L. bibracteatum P R-LC M
Malva sylvestrisL. M
Mentha pulegiumL. Mepu + 1 1 + E M E M
Myosotis siculaGuss. M. lingulatavar.sicula Mysi P R-NT 3 + 1 E E M
Myriophyllum alterniflorumDC. P RR-LC 1 C C I,C
Nitella opaca(C.Agardh ex Bruzelius) C.Agardh P IF 1 M,I
Nitella translucens(Persoon) C.Agardh H IF + M,I,C
Nymphaea albaL. H R-VU C C
Ornithopus compressusL. Orco + M
Panicum repensL. Pare 2.3 1.2 M M
Plantago coronopusL. Plco + M M
Plantago lanceolataL. Plla + M
Poa annuaL. Poan + M
Poa trivialisL. Potr + E
Polypogon monspeliensis(L.) Desf. Pomo + M
Portulaca oleraceaL. M
Ranunculus baudotiiGodr. R. aquatilissubsp.
baudotii,R. peltatus
Raba H + 3 E M,I,C
Ranunculus muricatusL. Ramu + 1 E M
Ranunculus ophioglossifoliusVill. Paop P IF-LC 1 E M
Ranunculus sardousCrantz. R. sardoussubsp.
intermedius
Rasa + + + E E M
Rumex pulcherL. Rupu + M
Sagina apetalaArd. M
Schoenoplectus lacustris(L.) Palla Scirpus lacustris H 1.2 C M,I,C C
Silene laeta(Aiton) Godr. Lychnis laeta Sila + E M
Solanum nigrumL. M
Solenopsis laurentia(L.) C.Presl. Laurentia michelii Sola P + + E E M
Sparganium erectumL. subsp.polyedrumAsch. & Graebn. H R-NT 1.2 C M,I,C
Tamarix africanaPoir. Taaf 1 M,I
Tolpis barbata(L.) Gartn. Toba + M
Trifolium campestreSchreb. M
Trifolium filiformeL. M
A.Daoud-Bouattouretal./C.R.Biologies334(2011)742–756747
