The main old representatives of the Mediterranean dendroflora, their origin and distribution
are treated. Relevant threats and strategy for in situ and ex situ conservation are also discussed
here

Castellano, G.

Marino, P.

Schicchi, R.

The main old representatives of the Mediterranean dendroflora, their origin and distribution
are treated. Relevant threats and strategy for in situ and ex situ conservation are also discussed
here

MARINO, Pasquale

CASTELLANO, Giuseppe

SCHICCHI, Rosario

Archivio istituzionale della ricerca - Università di Palermo

Biodiversity Journal, 2012, 3 (4): 401-406Biodiversity and evolution of the dendroflora in the Medi-terraneanPasquale Marino1, Giuseppe Castellano1 & Rosario Schicchi21Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Università degli Studi di Palermo, via Archirafi 3890123 Palermo, Italy2Dipartimento di Scienze Agrarie e Forestali, Università degli Studi di Palermo, via Archirafi 38 - 90123 Palermo, ItalyABSTRACT The main old representatives of the Mediterranean dendroflora, their origin and distributionare treated. Relevant threats and strategy for in situ and ex situ conservation are also discussedhere.KEY WORDS Biogeography; dendroflora; endemism; insularity.Received 11.05.2012; accepted 21.12.2012; printed 30.03.2013Proceedings of the 1st International Congress “Insularity and Biodiversity”, May 11th-13th, 2012 - Palermo (Italy)INTRODUCTIONThe Mediterranean basin is one of the 25 biodi-versity hotspots identified at a global level to whichthe storage is of essential importance (Myers et al.,2000). It is rich in islands of all extensions, fromSicily with its 25,700 square kilometres down to thepebble size of those; other large islands are Sardinia(24,090 sq km), Cyprus (9253 sq km), Corse (8748sq km), Crete (8258 sq km), Baleares (4,996 sqkm), Malta (316 sq km). This basin represents theremnant of the ancient Tethys Sea, a Mesozoicocean that underwent profound changes during theAlpine orogeny, beginning in the Middle Cretace-ous, about 100 Ma (Gradstein & al., 2004), and ex-tending to the late Miocene, about 7 Ma.Palaeoclimatic researchers studying the late Mio-cene (Messinian, 7.2-5.3 Ma) have identified anevent of regional aridity, during which most of theMediterranean Sea became a marsh (Kovar-Eder etal., 2008). Thereafter, during the Pliocene (5.3-1.8Ma), the Mediterranean seasonality and the regionalcooling accentuated around 4.5, 3.6, 3.2, 2.8 and 2.4Ma (Suc, 1984; Kovar-Eder et al., 2008; Jost et al.,2009). These climatic oscillations, ending with thePleistocene glaciations, resulted in the cumulativeloss of several thermophilic species from the Euro-pean continent, as well as in episodic expansions ofxerophytic communities (Pignatti, 1978; Suc, 1984;Palamarev, 1989). Palaeoclimatic analysis suggeststhe establishment of the current Mediterranean cli-mate seasonality, characterized by two intra-annualstress periods for plant growth, in summer and inwinter, during at least three climatic crises dated to3.2, 2.8 and 2.4 Ma (Suc, 1984; Fauquette et al.,1999, 2007; Bruch et al., 2006). By 10,000 BP co-niferous forests dominated by Pine and Juniper spe-cies were occurring; by 5000 years BP deciduoustrees of oak, elm, hornbeam beech etc., were beco-ming dominant (Willis & McElwain, 2002).THE MEDITERRANEAN DENDROFLORA:A FOCUS ON ANCIENT WOODY SPECIES Cupressaceae. This family appeared in theTriassic (200 Ma) with the genus Wriddingtoniathat at now only in South Africa occurs. During Eo-cene (55 Ma) Tetraclinis and Cupressus emerged inthe Mediterranean dendroflora (Palamarev, 1989).Tetraclinis articulata (Vahl) Mast. is the only onetaxon of the Callitroideae subfamily that is spreadin the northern hemisphere, in Morocco, SouthernSpain, and Malta (Fig. 1). The genus Cupressus in-cludes C. atlantica Gaussen and C. sempervirens L.The former occurs in Morocco (High Atlas), the lat-ter in Cyprus, Greece and in the Balkan coasts.Pinaceae. This family, which appeared in theMesozoic, about 150 Ma, includes several generathat are among the most important in the forestalMediterranean landscape: Abies, Cedrus and Pinus.Nine species, one natural hybrid and several varie-ties of Fir (Vidakovic, 1991) belong to the Mediter-ranean dendroflora. Palaeoecological studies basedon fossil pollen and plant macrofossils show thatduring the Pliocene (c. 5 Ma) the MediterraneanBasin was covered by vast forest ecosystems, pre-sumably including a common ancestor of the cur-rent Mediterranean Firs (Pignatti, 1978; Meyen,1987; Palamarev, 1989). From this common ance-stor, migrations and subsequent population frag-mentation led to smaller, isolated Fir forests aroundthe current Mediterranean Basin (Farjon & Ru-shforth, 1989) (Fig. 2). The genus Abies appears to have undergone si-gnificant morphological differentiation that doesnot necessarily imply reproductive isolation. Infactlong-term Mediterranean Basin dryness along asouth-eastern to north-western gradient may havestarted a Miocene-Pliocene speciation sequence.Pleistocene glacial cycles probably forced migra-tions leading to repeated contact between Fir spe-cies in glacial refugia (Linares, 2011). In this con-text is A. nebrodensis (Lojac.) Mattei, very rare withonly twenty-four mature individuals (Fig. 3).Speciation of the genus Cedrus dates back about58 Ma. Recent phytogeographic studies have revea-led several sites of refuge in the Mediterraneanmountains during the Pleistocene (2 Ma) (Svenning& Skov, 2005; Comes, 2004; Hellwig, 2004). Threespecies belong to the Mediterranea dendroflora:- Cedrus atlantica (Endl.) G. Manetti ex Car-rière (Middle Atlas, Morocco) (Fig. 4)- Cedrus libani A. Rich. (Lebanon and Turkey)- Cedrus brevifolia Elwes & Henry (Cyprus)The genus Pinus, the the richest in speciesamong all conifers, was already established in theCretaceous (145-66 Ma); in the Mediterranean itincludes:- Pinus halepensis Mill. (widespread in the basin)(Fig. 5)- Pinus nigra Aiton- subsp. nigra (Central Italy and Balkan area)- subsp. calabrica (Loud.) A. E. Murray (Sicily,Calabria, Corse) (Fig. 6)- subsp. salzmannii (Dunal) Franco (Spain, France)- subsp. dalmatica (Vis.) Franco (Dalmatia)- subsp. pallasiana Lamb. Holmboe (Romany,Greece, Turkey)- Pinus pinaster Aiton- subsp. atlantica Villar (Atlantic coastlands ofSpain, France and Portugal)- subsp. hamiltonii (Ten.) Villar. (Pantelleria andSouthern Spain)- subsp. renoui (Morocco)Angiosperms. Angiosperms, of prevalent Ter-tiary origin, represent the largest group in theworld. In the Mediterranean basin they play a veryimportant role in forest and secondary shrub com-munities showing high levels of specific diversity(e.g. Acer, Quercus, Pyrus, Malus, Ulmus). Manyof these taxa are of remarkable interest. Amongthese several very remarkable paleoendemics areincluded, such as Zelkova sicula Di Pasquale,Garfì et Quézel, which is confined in two very re-stricted localities of Sicily (Marino & Spadaro,2012) (Fig. 7).P. MARINO, G. CASTELLANO & R. SCHICCHI402Figure 1. Formations with Tetraclinis articulata Mast., HighAtlas, Morocco.THREATSFire, pasture and invasion of alien plants arethe main traits affecting the Mediterranean den-droflora (Table 1). Inclusion of congeneric taxa tothe native ones in reforestation projects is the mostserious threat of biological pollution and repre-sents an important factor in the genetic erosion(e.g. Fraxinus excelsior subsp. siciliensis Ilardi etRaimondo and Abies nebrodensis in Sicily)(Schicchi & Marino, 2011).Exotic fauna is another factor dangerous for thewood renoval. A boar of Balkan and its cross in Si-cily represent a very threat for biodiversity conser-vation like in main protected areas.From the phytopathological point of view the in-trodution of alien species can be identified as an im-prtant source of diseases for the native populations(Schicchi et al., 2008).DISCUSSIONMediterranean Islands possess ancient taxa da-ting back to Triassic (over 200 Ma) since Eocene(55 Ma); these are mainly Gymnosperms likeAbies, Cedrus, Cupressus, Pinus and Tetraclinis.This group suffers the highest risk, due the ecolo-gical competition and human threats. A relevantexample is represented by Abies nebrodensis thatin Sicily is located in a restricted area dominatedby Fagus sylvatica and where several exotic firswere introduced in the past.Cenozoic flora, also known as Terthiary flora,represent for the Mediterranean area a biggestgroup of woody species that dominate from thelevel of sea to the high mountains. Acer, Ulmus,Fagus, Quercus are the most important genera.Other taxa are Pyrus, Malus, Sorbus that grow inshrubby vegetation.Preservation of Mediterranean dendroflora is ofvital importance for the future of biodiversity.Human activity has shaped these biological resour-ces but tourism especially can result in destructivedeteriorattion. In addition, changing agricultural po-licies, especially the EU ones, are likely to alteraterural landscapes further.Conservation strategies of specific habitats on aregional scale is required to preserve biodiversity.In the Mediterranean Islands, strategies for in situand ex situ conservation are widely shared troughcollection of seeds and plants. An important role,improuving conservation strategy, is played by seed403Biodiversity and evolution of the dendroflora in the MediterraneanFigure 2. Hypothetical post-glacial expansion of A. alba based on molecular data and fossil records, and present distributionand diversity of the Mediterranean Abies species (Linares, 2011). 1) A. alba; 2) A. cilicica; 3) A. pinsapo; 4) A. numidica;5) A. cephalonica; 6) A. bornmuelleriana; 7) A. nordmanniana; 8) A. equi-trojani; 9) A. borisii-regis (A. • borisii-regis = A.alba • A. cephalonica); 10) A. nebrodensis; 11) A. pinsapo var. maroccana; 12) A. pinsapo var. tazaotana. P. MARINO, G. CASTELLANO & R. SCHICCHI404Figure 3. Abies nebrodensis in the native area, MadonieMountains, Sicily.Figure 4. A huge Cedrus atlantica tree, Middle Atlas, Morocco.Figure 7. Zelkova sicula in the locus classicus, IbleiMountains, Sicily.Figure 6. A monumental tree of Pinus nigra subsp. cala-brica in the southern slope of Etna volcano (Sicily).Figure 5. Natural Reserve "Pino d'Aleppo" the only oneindigenous station of Pinus halepensis in Sicily.banks and Botanic gardens in the main Islands.These living collections consist centuries of know-how and expertise that now means they play a keyrole in plant conservation. Many of these activitiescontribute to ex situ conservation, but botanic gar-dens also play an important role in in situ conser-vation.ACKNOWLEDGEMENTSUniversity of Palermo Funds are gratefully ack-nowledged.REFERENCESAiroldi Bruch A.A., Utescher T., Mosbrugger V., Gabrie-lyan I. & Ivanov D.A., 2006. Late Miocene climatein the circum-Alpine realm a quantitative analysis ofterrestrial palaeofloras. Palaeogeography Palaeocli-matology Palaeoecology, 238: 270-280.Comes H.P., 2004. The Mediterranean region - a hotspotfor plant biogeographic research. New Phytologist,164: 11-14.Farjon A. & Rushforth K.D., 1989. A classification ofAbies Miller (Pinaceae). Notes of the Royal Botani-cal Garden of Edinburgh, 46: 59-79.Fauquette S., Suc J.-P., Guiot J., Diniz F., Feddi N.,Zheng Z., Bessais E. & Drivaliari A., 1999. Climateand biomes in the West Mediterranean area duringthe Pliocene. Palaeogeography PalaeoclimatologyPalaeoecology, 152: 15-36.Fauquette S., Suc J.-P., Jiménez-Moreno G., Micheels A.,Jost A., Favre E., Bachiri-Taoufiq N., Bertini A., Clet-Pellerin M., Diniz F., Farjanel, G., Feddi N. & ZhengZ., 2007. Latitudinal climatic gradients in WesternEuropean and Mediterranean regions from the Mid-Miocene (!15 Ma) to the Mid-Pliocene (!3.6 Ma) asquantified from pollen data. Deep time perspectiveson climate change: marrying the signal from compu-ter models and biological proxies (ed. by M. Wil-liams, A.M. Haywood, F.J. Gregory and D.M.Schmidt), pp. 481-502. The MicropaleontologicalSociety/The Geological Society of London, London.Gradstein F., Ogg J., Smith A., Bleeker W. & Lourens L.,2004. A new Geologic Time Scale, with special refe-rence to Precambrian and Neogene. Episodes, 27: 83-100.Hellwig F.H.A., 2004. Centaureinae (Asteraceae) in theMediterranean-history of ecogeographical radiation.Plant Systematic and Evolution, 246: 137-162.Jost A., Fauquette S., Kageyama M., Krinner G., Ram-stein G., Suc J.P. & Violette S., 2009. High resolutionclimate and vegetation simulations of the Late Plio-cene, a modeldata comparison over western Europeand the Mediterranean region. Climate of the Past, 5:585-606.Kovar-Eder J., Kvacek Z., Martinetto E. & Roiron P.,2006. Late Miocene to Early Pliocene vegetation ofISLANDS AREA (KM2) MAIN ENDEMIC ENDANGE-RED TAXA THREATSSICILY 25708 Abies nebrodensisZelkova sicula Pasture, alien sp., fireSARDINIA 24090 Pinus pinea Fire, human activitiesCYPRUS 9253 Cupressus sempervirensCedrus brevifolia Fire, pastureCORSE 8748 Pinus nigra subsp. calabrica FireCRETE 8258 Zelkova abelicea Fire, pastureBALEARES 4996 Pinus pinaster subsp. renoui Fire, pastureMALTA 316 Tetraclinis articulata Fire, pastureBiodiversity and evolution of the dendroflora in the Mediterranean 405Table 1. Examples of Mediterranean dendroflora taxa and their main threats.southern Europe (7-4 Ma) as reflected in the mega-fossil plant record. Palaeogeography Palaeoclimato-logy Palaeoecology, 238: 321-339.Linares C.J.J., 2011. Biogeography and evolution ofAbies (Pinaceae) in the Mediterranean Basin: theroles of long-term climatic change and glacial refu-gia. Biogeography, 38: 619-630.Marino P. & Spadaro V., 2012. Due casi di rarità estremanella flora siciliana. In: Giardina G. Piante rare di Si-cilia (2th Edition). Università degli Studi di Palermo,DAB, pp. 289-291. ISBN 978-88-903108-9-8.Meyen S.V., 1987. Fundamentals of palaeobotany. Chap-man and Hall, London.Myers N., Mittermeier R.A., Mittermeier C.G., DaFonseca G.A.B. & Kent J., 2000. Biodiversity hot-spots for conservation priorities. Nature, 403: 853-858.Palamarev E., 1989. Paleobotanical evidences of the Ter-tiary history and origin of the Mediterranean sclero-phyll dendroflora. Plant Systematic and Evolution,162: 93-107.Pignatti S., 1978. Evolutionary trends in Mediterraneanflora and vegetation. Plant Ecology, 37: 175-185.Schicchi R., Bazan G., Castellano G., Ilardi V., MarinoP. & Surano N., 2008. Piano di Gestione Monti Ma-donie - Strategie gestionali. Università degli studi diPalermo, CIRITA.Schicchi R. & Marino P., 2011. Taxa relitti della flora fo-restale siciliana e problemi di conservazione. Biogeo-graphia, 30: 141-150.Svenning J.-C. & Skov F., 2005. The relative roles of en-vironment and history as controls of tree speciescomposition and richness in Europe. Journal of Bio-geography, 32: 1019-1033.Suc J.P., 1984. Origin and evolution of the Mediterraneanvegetation and climate in Europe. Nature, 307: 429-432.Vidakovic M., 1991. Conifers, morphology and variation.Zdravko Zidovec, Zagreb, 88 pp.Willis K.J. & McElwain J.C., 2002. The evolution ofplants. Oxford University Press, Oxford, New York,392 pp.P. MARINO, G. CASTELLANO & R. SCHICCHI406

Biodiversity and evolution of the dendroflora in the Mediterranean

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Biodiversity and evolution of the dendroflora in the Mediterranean

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