ecologia mediterranea Tome 30 fascicule 2, 2004 ISSN 0153-8756

SOMMAIRE – CONTENTS

P. D. DIMOPOULOS, E. BERGMEIER Wood pasture in an ancient submediterranean oak forest ...... 137

M. DUBAR, BUI-THI-MAI, S. NICOL-PICHARD & M. THINON Étude palynologique du carottage de Pont d’Argens (Roquebrune-sur-Argens, 30 fascicule 2, 2004 Tome Var) : histoire holocène de la végétation en Provence cristalline ; facteurs naturels et anthropiques ...... 147

K. KASSIOUMIS, K. PAPAGEORGIOU, T. GLEZAKOS & I.N. VOGIATZAKIS Distribution and stand structure of Taxus baccata populations in Greece; Results of the first national inventory ...... 159

CARSTEN F. D ORMANN, RACHEL KING Comparing the palatability of Mediterranean or non-native plants in Crete ...... 171

M. CONEDERA, M.C. MANETTI, F. GIUDICI & E. AMORINI Distribution and economic potential of the Sweet chestnut (Castanea sativa Mill.) in Europe ...... 179

J.-C. THIBAULT, R. PRODON & P. MONEGLIA Estimation de l’impact des incendies de l’été 2000 sur l’effectif d’un oiseau endémique menacé : la sitelle corse (Sitta whiteheadi) ...... 195

C. RATHGEBER, L. BLANC, C. RIPERT & M. VENNETIER Modélisation de la croissance en hauteur du pin d’Alep (Pinus halepensis Mill.) en région méditerranéenne française ...... 205

M. BOUAZZA, N. BENABADJI, R. LOISEL & G. METGE Évolution de la végétation steppique dans le sud-ouest de l’Oranie (Algérie) . . . . .219

FAITS DE CONSERVATION EN MÉDITERRANÉE MEDITERRANEAN CONSERVATION NEWS ...... 233

ANALYSES D’OUVRAGES ...... 245 ANNONCE DE COLLOQUE ...... 248

RevueRevue internationaleinternationale d’écologied’écologie méditerranéenneméditerranéenne

Tome 30 InternationalInternational JournalJournal Revue indexée dans Pascal-CNRS et Biosis Fascicule 2, 2004

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Revue internationale d’écologie méditerranéenne International Journal of Mediterranean Ecology

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BARBERO M., IMEP, Université Aix-Marseille III OVALLE C., CSI-Quilamapu, INIA, Chili EAULIEU DE B J.-L. , IMEP, Université Aix-Marseille III PEDROTTI F., Universita degli Studi, Camerino, Italie BROCK M., University of New England, Armidale, Australie PLEGUEZUELOS J. M., Université de Grenade, Espagne CHEYLAN M., EPHE, Montpellier PONEL P. , IMEP, CNRS, Marseille DEBUSSCHE M., CEFE-CNRS, Montpellier PRODON R., EPHE, Montpellier FADY B., INRA, Avignon RIDCHARSON D. M., University Cape Town, Afrique du Sud GRILLAS P., Station biologique Tour du Valat, Arles

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KREITER S., ENSA-M-INRA, Montpellier TROUMBIS A., University of the Aegean Mytilene, Grèce LE FLOC’H E., CEFE-CNRS, Montpellier URBINATI C., Agripolis, Legnaro, Italie

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Revue internationale d’écologie méditerranéenne International Journal of Mediterranean Ecology

Tome 30 • Fascicule 2 • 2004

Wood pasture in an ancient submediterranean oak forest (Peloponnese, Greece) Sylvopastoralisme dans une ancienne forêt méditerranéenne de chênes (Péloponnèse, Grèce)

P. D. Dimopoulos1, E. Bergmeier2 1. Department of Environmental and Natural Resources Management, University of Ioannina, Seferi 2, GR-30100 Agrinio, Greece; Fax +30 641 39576: E-mail: [email protected] 2. Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Georg-August-Universität Göttingen, Untere Karspüle 2, D-37073 Göttingen, Germany; Fax +49 551 39 2287; E-mail: [email protected] *corresponding author 137

Abstract Résumé In this study the effects of wood-pasturage on species composition Dans la présente étude sont décrits les effets du sylvopastoralisme and forest structure in the Quercus frainetto forest of Folói are des- sur la composition spécifique et la structure de peuplements dans cribed. This is the most extensive broadleaved forest of Peloponnese la forêt à Quercus frainetto de Folói. Cette forêt, la plus étendue and southern Greece and unique in that there is evidence of several du Péloponnèse et du sud de la Grèce, est unique par le fait de son thousand years of existence. The variation in plant species compo- existence probablement plurimillénaire. La variation de la com- sition among, and the differences between, grazed and ungrazed position spécifique au sein de peuplements pâturés ou non, et les forest stands are analysed by means of ordination (correspondence différences entre ces deux types de peuplements ont été analysées par analysis). Species indicative for grazing or its withdrawal are listed. ordination (analyse des correspondances). Des espèces indicatrices Annuals and certain perennials with good regeneration capacity are du pâturage et de son absence sont listées. Les espèces annuelles et indicative for grazed plots, while a dense shrub layer with Arbutus certaines vivaces avec une bonne capacité de régénération sont liées unedo and Erica arborea is related to ungrazed plots. Generally, in aux placettes pâturées, tandis qu’une strate arbustive dense formée the absence of grazing the development of the herb and shrub layer par Arbutus unedo et Erica arborea caractérise les placettes non is enhanced. Forest stands in exclosures tend to produce denser cano- pâturées. De façon générale, en l’absence de pâturage, les strates pies, oak rejuvenation is more abundant, and the trees are higher herbacées et arbustives sont mieux développées. Les forêts à l’inté- and more vital than outside. In grazed woodland, litter and organic rieur des enclos ont tendance à produire des canopées plus denses, matter are less abundant and the degree of parasitism byLoranthus la régénération des chênes y est plus abondante, et les arbres sont europaeus is higher. Our results suggest two possible conservation plus hauts et plus vigoureux qu’à l’extérieur. Dans les peuplements options for the study area, viz. (a) controlled grazing regime in the pâturés, la litière et la matière organique sont moins abondantes, et framework of a traditional but sustainable agro-silvopastoralistic le degré de parasitisme parLoranthus europaeusest plus élevé. Nos system or (b) a concept towards a natural forest ecosystem. résultats suggèrent deux options possibles pour la conservation de la zone étudiée : a) un régime de pâturage contrôlé dans le cadre d’un système agropastoral traditionnel mais durable ou b) un régime Key-words visant un écosystème forestier à caractère naturel. Grazing, Greece, Old forest,Quercus frainetto, Silvopastoralism Mots-clés Pâturage, Grèce, vieille forêt, Quercus frainetto, Sylvopastoralisme

ecologia mediterranea, tome 30, fascicule 2, 2004, p. 137-146 ◆ P. D. DIMOPOULOS & E. BERGMEIER

vely as an attempt to civilize wilderness and to establish cultivation in less favourable regions. Although close to INTRODUCTION Olympia the hinterland of Ilía remained a little attended Interest in wood pasture has increased a great deal region in antiquity. To our knowledge, the first mentio- lately in many European countries (Papanastasis et al., ning of an historical event in the forest area of Folói dates 1999; Redecker et al., 2002). In western and central back to the battle between Alarichos and Stilichon in AD Europe re-introduction of wood pasture is currently 397 (Christopoulos, 1978). under discussion, with the principal aims of enhancing Grazing by domestic herbivores causes quantitative forest dynamics and increasing biodiversity (Pott, 1999; (number of plant individuals, species numbers) and qua- Vera, 2000; Schmidt & Heile, 2001; Spencer, 2002). litative (species composition, phenological traits) effects Modern forestry supports tall dense forest for economic on Mediterranean open habitats (Noy-Meir et al., 1989; reasons and, owing to the browsing of seedlings and juve- Fernandez Alés et al., 1993; Bergmeier & Matthäs, 1996; nile trees, considers wood-pasturage as detrimental to the Bergmeier, 1998). However, not many studies have dealt forest and chiefly responsible for the decline of wooded with woodland grazing in the Mediterranean, or the areas and the structural senescence of the tree stands. effects of cessation of grazing to Mediterranean deci- Present silvopastoralism in Europe is largely restricted to duous woodlands (Di Pasquale & Garfi, 1998; Debussche countries of the wider Mediterranean and the Balkans. et al., 2001). Few studies explicitly state which species in 138 Grazing by domestic animals has widely been practiced oak woodlands increase after silvopastoralism has been in virtually all forests except for the most remote ones. given up, and which decrease (Debussche et al., 2001). In traditional silvopastoral farming systems, submedi- Based on field studies in the Foloi forest, our paper terranean deciduous and mediterranean sclerophyllous attempts to provide such information and addresses the woodlands are chiefly involved. Deciduous oak forest is following questions: highly esteemed due to its mast production in autumn Is the species composition of oak forest a suitable as food for pigs. But also other domestic animals such indicator for wood pasture? as sheep, goats and cattle benefit from the relatively light Which species of oak forest profit from grazing and conditions in oak woodlands which support a fairly dense which from its withdrawal? and plant-rich ground vegetation. To which extent differs the structure of ungrazed oak For the present study, the forest of Folói (Kápellis; forest from that of grazed stands? Pholóë in antiquity; Ilía, Peloponnisos, Greece) was cho- Is silvopastoralism an obstacle to the rejuvenation of sen. It has been used for charcoal burning and pasturage oak? for centuries, as travellers’ reports suggest (Philippson, Ancient Mediterranean forests are in urgent need of 1892; Pritzel, 1908; Rothmaler, 1943). The major part protection but conservation priorities have hardly been has been used as wood pasture for sheep and pigs within discussed, owing chiefly to the lack of ecological infor- the local rural economies but remote parts show little or mation. Our final point of discussion is therefore: Which no signs of grazing at present. conclusion can be drawn from our findings for the con- In Greece, as elsewhere in the Mediterranean, most servation and sustainable use of the specific study area? oak woodlands have been, or still are, subject to coppi- cing at more or less regular intervals. Single-stemmed old-growth oak woodlands as in our study area, however, are exceedingly rare (Bergmeier et al., 2004). The forest of Folói is the most extensive submediterranean non-cop- piced oak forest in Peloponnisos, and certainly among the STUDY AREA oldest existing. It was known already in Greek mythology, according to which it was frequented by centaurs, hor- The study area, the forest of Folói (Kápellis), com- ses with human body, the personifications of mountain prises 3100 ha of broadleaved forest. It is situated in forest wilderness. Among the many myths around the the eastern part of Ilía (Elis in antiquity) in western Greek hero Herakles is one with the forest of Folói as Peloponnisos (fig. 1). The Folói plateau constitutes the the scenery of a guest meal provided for the hero that upper and most extensive in a series of conglomerate ended up in a massacre among the centaurs. Herakles tables between Mt Erimanthos and the river Alpheios also encouraged prehistoric people to clear part of the (Philippson, 1959). The plateau is very slightly inclined extensive forest. The myth can be interpreted figurati- with less than 700 m of altitude in the north and almost 800 m in the south. It consists of Pleistocene continental

ecologia mediterranea, tome 30, fascicule 2, 2004 WOOD PASTURE IN AN ANCIENT SUBMEDITERRANEAN OAK FOREST ◆

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Figure 1. Position of the study area and distributionQuercus of frainetto forest drawn from an aerial photograph of 1992. Tree crowns in stands with open canopy (1) do not overlap and the cover is open or sparce (< 40 %); closed stands (2) with overlapping crowns represent dense canopy covers (> 60 %); intermediate stands (40-60 %) are infrequent and included into (2).

deposits, represented chiefly by conglomerates (IGME, to our days. Philippson (1892: 36), however, mentioned 1983). The soils are commonly fairly deep cambisols, forest degradation caused by extensive charcoal produc- acidic, base-poor and waterpermeable. The climate is tion. Beside of charcoal industry, grazing by domestic Mediterranean-type, with mild humid winters and dry animals (sheep, pigs, more rarely goats) has widely been warm summers, but in the western Peloponnese modi- practiced in the forest (Rothmaler, 1943) and is still of considerable importance for the local rural economies. fied towards sub-oceanic conditions, particularly so in the The deciduous Quercus frainetto is the predominant oak, mountains. That is why, in spite of the southern position, as was already mentioned by Heldreich (1862), Pritzel the annual precipitation is above 1000 mm, and the arid (1908) and Rothmaler (1943). There are no traces of fire period restricted to comprise about 90 days (meteorologi- in the present oak forest, nor is fire mentioned as a means cal station Andritsena, unpubl. data). Due to the infertility of forest or grazing management by the early geobotani- of the soils, the area was never densely populated. This cal travellers cited above. Extensive nearby areas of pine is why a considerable extent of the forest was preserved ecologia mediterranea, tome 30, fascicule 2, 2004, p. 137-146 ◆ P. D. DIMOPOULOS & E. BERGMEIER

overlooked). The number of juvenile oaks in ungrazed forest, on the other hand, burnt in the 1990s. The fire forest was assessed in 8 plots of 1 m² each, laid out at did not expand to the oak forest. In spite of the serious regular intervals along a diagonal inside the exclosure, human impact, major areas remained spacious tall forest and for the grazed forest the same number of plots was of single-stemmed, non-coppiced trees, today an excep- arranged along an outside extension of the diagonal. tionally rare type of woodland in southern Greece and In order to explore the relevance of grazing for elsewhere in the Mediterranean. explaining the variation in the data set, the 42 relevés (30 in grazed sites, 12 in ungrazed sites) were subjected to indirect gradient analysis (Correspondence analysis, CA). The settings were biplot scaling with focus on inter-species distances, no downweighting of species, ETHODS M and no transformation. The ordinations were performed Silvopastoral activities (expansion or decrease of the using CANOCO 4 (ter Braak & Šmilauer, 1998). For grazed area; intensity; composition of livestock) have statistical calculations on species frequency, forest and always been fluctuating in history, along with various tree parameters, seedling numbers, and the degree of socio-economic factors. Major parts of the forest are mistle infection, Mann-Whitney U-Test was used, with currently subject to grazing, but as for the rest, there is the significance levels expressed by 2-tailed Monte Carlo 140 no way telling when exactly a given site was grazed last. significance. Therefore, we distinguished between stands which are Nomenclature of taxa followsFlora Europaea (Tutin presently grazed, and others without present grazing et al., 1968-1980, 1993). impact. The absence of grazing was judged from the absence of browsed or grazed plants and from the lack of droppings. The species composition of grazed and non-grazed stands was studied in 30 and 12 quadrats, respectively, each of 400 m². Minimum distance between RESULTS quadrats was c. 150 m, but usually more than 300 m. In order to restrict the selection to sites comparable in The ordination of the 42 quadrats of Quercus frainetto terms of abiotic parameters, only forests with more or less forest by means of CA revealed an arched plot structure closed Quercus frainetto canopy, i.e., with more than 60 which is expected for data sets with one predominant % canopy cover were included. Most stands have 65-85 gradient (figure 2). Along the horizontal axis (axis 1), gra- % canopy cover (figure 1). Stands on steep slopes and zed plots formed the left wing of the arch, while the right in ravines were excluded. Species abundance in tree (t), wing was composed of non-grazed plots. Hence grazing shrub (s) and herb (h) layers were distinguished (t > 4 regime constitutes the most important gradient explaining m; 4 m > s > 100 cm; h < 100 cm). a great deal of variation in species composition. Species such as Cynosurus echinatus, Poa bulbosa and Trifolium Four of the ungrazed quadrats were in two grazing campestre scored in the far left of the diagram, indicating exclosures of about two hectares in total which had their preferential occurrence in grazed stands. In contrast, been established in April 1964. In one of the exclosures Arbutus unedo and Erica arborea shrubs turned out to be (N37°46’39”, E21°44’46”), for silvicultural purposes a characteristic for non-grazed plots. In the central part of stand analysis had been performed in November 1964 the diagram taxa without clear preference to any mana- (Panagiotidis, 1965). Among other parameters, stem gement regime were assembled. diameter at breast height (BHD) and tree height (TH) Species preferences for grazed and non-grazed forests had been assessed. We performed a similar analysis in are displayed in more detail in table 1. Annual species 1999 using one plot of 8 × 50 m in the exclosure, the were found to be restricted largely to the grazed plots. other of the same size in a grazed site further east 30 m Among the perennials, certain species with the poten- outside the fence. Stand profiles and crown projection tial to resprout from basal buds or subterranean tubers maps were drawn, and pH as well as visual properties (Oenanthe pimpinelloides,Asphodelus ramosus, Poa trivialis of soil profiles were assessed. The following parameters subsp. sylvicola, Poa bulbosa) occurred significantly more were recorded per tree: BHD, TH, number of oak mistles frequently in grazed plots. Shrub species, in particular (Loranthus europaeus) as an indicator for reduced vitality Arbutus unedo and Erica arborea, to somewhat lesser (only medium-sized to large Loranthus individuals were degree also juvenile plants of these species in the herb counted since smaller ones would easily have been layer, are a specific feature of non-grazed plots.

ecologia mediterranea, tome 30, fascicule 2, 2004 WOOD PASTURE IN AN ANCIENT SUBMEDITERRANEAN OAK FOREST ◆

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Figure 2. Ordination diagrams (correspondence analysis) displaying floristic similarities of 30 grazed and 12 non- grazed plots (dots, left diagram) and selected species scores (right diagram). Species names are abbreviated by 4 letters of the generic name and 3 of the specific epithet (full names in table 1). Their positions were slightly adjusted if necessary to avoid overlap. Eigenvalues of axis 1: 0.229, axis 2: 0.168.

The mean cover values of the Quercus frainetto canopy lower than in the grazed plot (table 3). If compared and the field layer tend to be higher in the non-grazed with the mean values for all trees in 1964, the trees have plots though not significantly (table 2). Quercus frainetto become 5 m taller at an average within 35 years, and the in the shrub layer occurred with high constancy in both BHD increment was 7 cm. The ratio TH/BHD remai- regime types but was more abundant in the non-grazed ned almost constant in the exclosure while in the grazed plots. The cover of the shrub layer was very variable both stand a considerable decrease was noted (table 3). The in grazed and non-grazed stands, chiefly due to the varia- age structure of the trees is uneven, and in 1964 11 % of tion in cover values of the Q. frainetto understorey, but the trees had BHD values > 40 cm (Panagiotidis, 1964). significantly and altogether more than three times higher The crown projection revealed more than 80 % canopy in non-grazed than in grazed stands (table 2). cover in the fenced plot, as against about 70 % in the Stand analyses of a non-grazed plot in an exclosure neighbouring grazed one (figures 3 and 4). The lower and a grazed one nearby outside the fence revealed non-branched part of the stems is generally longer in the significantly higher values for tree height (TH) in the exclosure, and the branches in the lower two thirds of non-grazed plot while mean stem diameter (BHD) was the trees are more scattered and with less foliage. Dead ecologia mediterranea, tome 30, fascicule 2, 2004, p. 137-146 ◆ P. D. DIMOPOULOS & E. BERGMEIER

Treatment grazed not grazed p Grazed Not grazed p number of plots 30 12 Number of plots 30 12 canopy cover 71.0 ± 11.8 75 ± 8.4 0.086 (ns) Woody species cover shrub layer 11.1 ± 16.1 39.5 ± 22.2 0.000 (***) Arbutus unedo s . 100 *** cover herb layer 43.7 ± 20.7 50.5 ± 18.5 0.297 (ns) Arbutus unedo h 3 83 *** Table 2. Oak forest parameters of the grazed and non-grazed plots. Erica arborea s 20 91 *** Mean co ver values are in % with standard deviation. Significance levels Rubus canescens 53 91 *** are * (p < 0.05); ** (p < 0.01); *** (p < 0.001); ns, not significant. Sorbus torminalis h 333ns

Annuals Cynosurus echinatus 63 . *** branches are more numerous in the grazed plot. The oak Trifolium campestre 46 .* mistle Loranthus europaeus occurred with a mean of 3.2 (± 2.6) individuals per tree while the ratio was 0.9 (± Aira elegantissima 30 . ns 1.2) Loranthus individuals per tree in the exclosure (p = Cerastium brachypetalum 30 . ns 142 0.006). We have found 27 (± 19) juveniles ofQ. frainetto Perennial herbs and subshrubs per m² in the grazed and 60 (± 24) in the ungrazed plots – more frequent in grazed plots (p = 0.012) (table 3). The soil profiles were roughly 3-layered both inside Oenanthe pimpinelloides 96 58 *** and outside the exclosure, and the soil type was identified Poa trivialis ssp. sylvicola 90 50 *** as cambisol (Braunerde). Base saturation is low, and the Asphodelus ramosus 67 25 ** deep lime-free B horizon is markedly acidic (pH 4.6-5.5).

Trifolium physodes 88 83 ** Differences between the plots refer particularly to the humus layer. In the grazed plots, the latter is absent or, Poa bulbosa 50 16 ns if present, thin (up to 2 cm) and largely without obvious – more frequent in ungrazed plots mycelia. Litter is sparse and often absent. In the exclosu- Stipa bromoides 46 100 * res, there is high fungal activity in the humus layer, and litter in various stages of decomposition was 2-7 cm thick Clinopodium vulgare 36 75 * and covers most of the surface area. Potentilla micrantha 76 100 *

Brachypodium sylvaticum 85 100 *

Aremonia agrimonoides 50 83 * Symphytum bulbosum 43 75 * DISCUSSION Brachypodium rupestre 13 50 ns The species composition of grazedQ. frainetto forests Teucrium chamaedrys 341nsdiffers considerably from that of non-grazed stands. Dorycnium hirsutum 641nsAnnual species in particular qualify as grazing indicators, at least in dense stands with a more or less closed canopy. Cephalanthera longifolia 641nsAmong the perennial herbs and subshrubs, most species Achillea ligustica 633nsof deciduous oak forest seem to be not or negatively Lathyrus laxifl orus 76 100 ns affected by grazing. Exceptions include Oenanthe pimpi- nelloides and Poa trivialis subsp. sylvicola, both supplied Luzula forsteri 82 100 ns with subterranean tuberous or knotted swellings which enable regeneration; Asphodelus ramosus, largely avoided Table 1. Constancy values (given in %) by herbivores and locally abundant in overgrazed pastu- and frequency differences of selected species in grazed res, and Poa bulbosa, a mat-forming pasture grass. and not grazed Quercus frainetto forest. The forest structure in non-grazed stands, as exempli- s – shrub layer (1-4 m), h – herb layer (< 1 m). Frequency differences fied by the exclosures, is denser, the trees are taller, and indicated by Mann-Whitney U-test significance levels: P < 0.05: *; there is pronounced canopy competition. The trees in the P < 0.01: **; P < 0.005: ***; ns: not significant.

ecologia mediterranea, tome 30, fascicule 2, 2004 WOOD PASTURE IN AN ANCIENT SUBMEDITERRANEAN OAK FOREST ◆

Year 1964 1999 1999 Treatment grazed grazed not grazed number of trees 524 10 9 TH (m) 20.6 ± 1.6 23.9 ± 2.8 25.6 ± 1.8 p = 0.009 ** BHD (cm) 22.4 ± 3.1 34.5 ± 4.5 29.5 ± 4.5 p = 0.049 * TH/BHD 92 69 87 Loranthus individuals per tree 3.2 ± 2.6 0.9 ± 1.2 p = 0.006 ** number of juv. oaks 27 ± 19 60 ± 24 p = 0.012 *

Table 3. Tree and site parameters obtained from stand analyses in 1964 when the exclosure was installed, and in 1999 in the exclosure and outside next to it.

Mean values with standard deviation are given. TH = mean tree height, BHD = mean breast height diameter. Significance levels refer to stand analyses in 1999; levels as in table 2.

143

Figure 3. Stand profile (a depth of 8 m is recognized) and crown projection of a grazed Quercus frainettoforest stand. Dots on the projection indicate the position of stems, triangles that of weathered stumps.

grazed stands tend to be less high, with more branches vitality of trees and in species composition are almost in the trunk area and with more investment into radial certainly related to the considerable differences obser- stem growth. The higher degree of infection by parasitic ved in present litter and humus layers. The litter layer Loranthus suggests that oak trees are less vital in heavily and the higher content of organic matter are important grazed forest. Since geological and topographic condi- in maintaining rapid infiltration rates, absorbing many tions are largely identical for all plots, differences in the times its own weight of water (Pritchett & Fisher, 1987). ecologia mediterranea, tome 30, fascicule 2, 2004, p. 137-146 ◆ P. D. DIMOPOULOS & E. BERGMEIER

Figure 4. Stand profile (a depth of 5 m is recognized) and crown projection of an ungrazedQuercus frainetto forest exclosure plot. Dots on the projection indicate the position of stems; triangles that of weathered, sixangles that of resprouting stumps. 144 Quadrats in the profile indicateArbutus rejuvenationof >1 m, circle: resproutingQ.frainetto stump.

In the exclosure, litter covers the ground almost totally, dense herb layer of oak seedlings and saplings supports and moisture is retained much more effectively. Annuals litter and humus accumulation, thus improving soil water occur only on naked mineral soil, in conditions which are and nutrient conditions which, in turn, are favourable for absent in the exclosure (or restricted to stem bases). This rejuvenation. Browsing may be of little direct effect on the is the result of wind turbulence dislocating foliage and juveniles but trampling is destructive to the herb layer. preventing accumulation of organic matter (Wilkeet al., Soil compaction and depletion are common features in 1993). The wind effect is reduced if a shrub or subshrub grazed woodlands (Bezkorowajnyj et al., 1993; Sibbald, layer is developed. Such a layer is represented in the oak 1999). Our findings suggest that they may be interpreted forest by the regrowth of Q. frainetto, the most frequent as an indirect effect of animals due to decreased litter species in the herb layer, and, in non-grazed stands, also accumulation rather than directly by trampling. by Arbutus unedo and Erica arborea. In a study on post- grazing successional oak woodland in southern France Debussche et al. (2001) found shrub species among the increasing taxa but not among the decreasing. Grazing (by sheep and pigs as in the study area) does not prevent CONCLUSION AND FINAL REMARKS oak rejuvenation but young oaks are less abundant. In The forest of Folói forms part of an area named fact, since grazing is likely to prevent a dense Arbutus ‘Oropedio Folois’ (9723 ha), chosen to become a and Erica understorey, moderate silvopastoralism might Special Conservation Area, eligible to be included in the even favour Q. frainetto rejuvenation. In exclosures, the European ‘Natura 2000’ network of Sites of Community

ecologia mediterranea, tome 30, fascicule 2, 2004 WOOD PASTURE IN AN ANCIENT SUBMEDITERRANEAN OAK FOREST ◆

Interest. Regulative arrangements and administrative for skilfully preparing the figures; M. Klescewski and H. measures for Special Conservation Areas are currently Gondard, both Montpellier, for their linguistic help with initiated, including the establishment of a management the résumé; E. Vidal and an anonymous reviewer for sug- plan. Such a plan, however, cannot be worked out unless gestions to improve the manuscript. the conservation priorities are clearly defined. From our study two possible concepts may be suggested: (a) Folói represents an outstanding example of an agro- silvopastoral system. Such ecosystems are vanishing References in Europe and almost lost in most countries. They are BERGMEIER E., 1998. Flowering intensity of phrygana plants considered a traditional asset worthy of protection. after fencing. Israel. J. Plant Sci. 46: 41-46. The history of human interference in the Folói area BERGMEIER E., DIMOPOULOS P. , THEODOROPOULOS K. & is long but today’s combined impacts on the forest ELEFTHERIADOU E., 2004. Zonale sommergrüne Laubwälder (grazing, charcoal production, forestry, agriculture) der südlichen Balkanhalbinsel. Tuexenia (in press). are far from sustainable. Maintaining wood pasture in BERGMEIER E. & MATTHÄS U., 1996. Quantitative studies Folói requires a balanced grazing regime and a strict of phenology and early effects of non-grazing in Cretan control of other kinds of impact. phrygana vegetation. J. Veg. Sci. 7: 229-236. (b) On the other hand, Folói constitutes a unique exam- BEZKOROVAJNYJ P. J . , GORDON A.M. & MCBRIDE A.A., 1993. 145 ple of submediterranean tall oak forest. As our study The effect of cattle foot traffic on soil compaction in a silvo- shows, it it severely suffering in places from grazing pastoral system. Agroforestry Systems 21: 1-10. but the conditions of regeneration towards a natural C forest are better than anywhere else. HRISTOPOULOS G. (ED.), 1978. Istoria tou Ellinikou Ethnous. [The history of the Greek Nation.] Vol. 7 (Vizantinos Any management plan and conservation measures Ellinismos-Protovizantini chroni). Ekdoti Athinon, Athína. depend on which alternative is given priority. It is clear, DEBUSSCHE M., DEBUSCHEE G. & LEPART J., 2001. Changes in from the results of our paper, that the two conservation the vegetation of Quercus pubescens woodland after cessation visions can hardly be realized simultaneously in one and of coppicing and grazing. J. Veg. Sci.12: 81-92. the same site. It is also evident that a Special Conservation DI PASQUALE G. & GARFI G., 1998. Analyse comparée de Area cannot be established without the acceptance and l’évolution de la régénération de Quercus suber et Quercus co-operation of the resident farmers and villagers. The pubescens après élimination du pâturage en forêt de Pisano management plan will have to make an attempt to (Sicile sud-orientale). Ecol. Medit. 24: 15-25. accomodate both options: e.g., by installing a core zone FERNANDEZ ALÉS R., LAFFARGA J.M. & ORTEGA F., 1993. where grazing is to be prohibited, and a buffer zone with Strategies in Mediterranean grassland annuals in relation to controlled grazing regime. With the establishment of a stress and disturbance. J. Veg. Sci. 4: 313-322.

European network of conservation sites the problem of HELDREICH TH. VON, 1862. Die Nutzpflanzen Griechenlands. harmonization of the options natural forest and traditio- Athens. nal silvopastoralism will be of increasing relevance. Folói IGME (ED.), 1983. Geological Map of Greece 1/500 000 (red. may well serve as a model on how to balance the respec- J. Bornovas & T. Rondogianni-Tsiambaou).nd 2 ed. Athína. tive management and conservation measures. NOY-MEIR I., GUTMAN M. & KAPLAN Y., 1989. Responses of Mediterranean grassland plants to grazing and protection.J. Ecol. 77: 290-310.

PANAGIOTIDIS N.TH., 1965. Makrochronii dhasike piramatike ACKNOWLEDGEMENTS epithanie. [Langfristige forstliche Versuchsflächen.] Athine. 51 pp. PAPANASTASIS V. P. , FRAME J. & NASTIS A.S. (EDS.), 1999. We thank L. Boskos, F. Galanos, G. Karetsos and Grasslands and woody plants in Europe. Proceedings Internat. K. Varelides, Research Forest Institute of Athens Occ. Symp. European Grassland Federation, Thessaloniki, (NAGREF), for supplying us with stand analysis data Greece, May 27-29, 1999. Thessaloniki. from the late N. Panagiotidis; H. Dres, retired forester PHILIPPSON A., 1892. Der Peloponnes. Versuch einer Landeskunde of the Folói forest, for discussions and informations on auf geologischer Grundlage. Berlin. the study area; U. Bergmeier for support and assistance PHILIPPSON A., 1959. Die griechischen Landschaften 3 (2). in the field; C. Adamidis, Ioannina, for statistical advice; Der Peloponnes, Teil 2: Der Westen und Süden der Halbinsel. P. Lampropoulos, Patras, and G. Amschlinger, Freiburg, Klostermann, Frankfurt am Main. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 137-146 ◆ P. D. DIMOPOULOS & E. BERGMEIER

POTT R., 1999. Diversity of pasture-woodlands of north-western in Europe, Proceedings Internat. Occ. Symp. European Germany. In: Kratochwil A. (ed.), Biodiversity in ecosystems. Grassland Federation, Thessaloniki, Greece, 27-29 May Kluwer Acad. Publ., Dordrecht: 107-132. 1999: 133-144.

PRITCHETT W. & FISHER R., 1987. Properties and management of SPENCER J., 2002. Managing wood pasture landscapes in England: forest soils. Wiley, New York. the New Forest and other more recent examples. In: Redecker PRITZEL E., 1908. Vegetationsbilder aus dem mittleren und B., Finck P., Härdtle W., Riecken U. & Schröder E. (eds.), südlichen Griechenland. Bot. Jahrb. Syst. Pflanzengesch. Pasture landscapes and nature conservation. Springer, Berlin, Pflanzengeogr 41: 180-214. Heidelberg: 123-136. REDECKER B., FINCK P. , HÄRDTLE W. , RIECKEN U. & SCHRÖDER TER BRAAK C.J.F. & ŠMILAUER P., 1998. Canoco Reference E. (EDS.), 2002. Pasture landscapes and nature conservation. Manual and User’s Guide to Canoco for Windows: Springer, Berlin, Heidelberg. Software for Canonical Community Ordination (version 4). Microcomputer Power, Ithaca, NY, USA. ROTHMALER W., 1943. Die Waldverhältnisse im Peloponnes. Intersylva 3, 329-342. TUTIN T. G. ET AL. (EDS.), 1968-1993. Flora Europaea, Vols. 2-5 nd SCHMIDT M. & HEILE H., 2001. Beweidung von Hutewäldern im and Vol. 1, 2 ed. Cambridge University Press, Cambridge. Reinhardswald – Pro und Kontra. Jahrb. Naturschutz Hessen VERA F.W.M., 2000. Grazing ecology and forest history. Oxon 6: 184-190. Cabi Publ. 146 SIBBALD A.R., 1999. Silvopastoral agroforestry: soil-plant-animal WILKE B., BOGENRIEDER A., WILMANNS O., 1993. Differenzierte interactions in the establishment phase.In: Papanastasis V.P., Streuverteilung im Walde, ihre Ursachen und Folgen. Frame J. & Nastis A.S. (eds.), Grasslands and woody plants Phytocoenologia23: 129-155.

ecologia mediterranea, tome 30, fascicule 2, 2004 Étude palynologique du carottage de Pont d’Argens (Roquebrune-sur-Argens, Var) : histoire holocène de la végétation en Provence cristalline ; facteurs naturels et anthropiques Pollen analysis of the core of Pont d’Argens (Roquebrune-sur-Argens, Var): Holocene vegetation history in the siliceous Provence; natural and anthropic factors

Dubar Michel1, Bui-Thi-Maï1, Nicol-Pichard Sylvie2 & Thinon Michel3 1. CEPAM (UMR-CNRS 6130), bât. 1, 250 rue Albert-Einstein, 06560 Valbonne. [email protected] 147 2. Museum d’Histoire naturelle de Marseille, palais Longchamp, 13004 Marseille 3. IMEP (UMR-CNRS 6116), université Paul-Cézanne / Aix-Marseille III, faculté des sciences et techniques, case 462, 13397 Marseille cedex 20

Résumé Abstract L’analyse palynologique des 28 derniers mètres du remblaiement The palynological analysis of the upper 28 meters of the Holocene holocène du delta de l’Argens, correspondant à l’intervalle 8 000- infill of the Argens Delta coinciding with the 8000-3000 BP 3 000 BP, permet une première restitution de l’histoire de la forêt period, has allowed a preliminary reconstruction of the history de la Provence cristalline. Cette histoire est marquée, à l’origine, par of the vegetation of Siliceous Provence. Originally there was a le développement d’une forêt de chênes caducifoliés et de bruyères mixed deciduous oak and arborescent healther forest. The absence arborescentes. L’absence ou quasi-absence de taxons aujourd’hui or near-absence of taxa which are nowadays very common such as majeurs comme le châtaignier et le chêne-liège est remarquable. the chesnut or the cork-oak is to be noted. The forest cover decreased Cette forêt commence à décliner à partir de 6 500 BP, sous l’effet progressively from 6500 BP in response to natural (climate, sea- d’un début d’anthropisation ou de causes naturelles (climat, niveau level, soils, and internal factors of the forest ecosystem) or anthropic de la mer, évolution des sols et facteurs internes à l’écosystème fores- causes. A first threshold of decline around 6000 BP and later a tier). Les modifications sont nettes vers 5 500 BP et deviennent plus drastic modification of the forest cover around 3000 BP, may be radicales vers 3 000 BP avec une très large dominance des taxons certainly interpretated as man-made. héliophiles. Ces transformations sont incontestablement attribuables à l’intervention humaine. Key-words Vegetation, holocene, siliceous Provence, neolithic anthropisation Mots-clés Végétation, holocène, Provence cristalline, anthropisation néolithique

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The original vegetation before anthropisation combined decidu- Abridged version ous oak and arborescent healther in a mixed forest. This was the The questions which we attempt to answer focus on the state precise time of the “Climatic Optimum” of the Holocene which of the vegetation in the Cristalline Provence before Man’s impact resulted from forest reconquest at the end of the glaciation. Of course and the history of some present major taxa such asQuercus suber after the optimum, the forest cover declined slowly however without L., Erica and Castanea sativa L. its mesophilous characteristics was really modified. A palynological study was thus carried out on a core bored In Eastern Provence, further East than the Tanneron Block, in of the Holocene Delta of the Argens River. Originating in the humidified and bounded by Alpine influences, the mesophilous state calcareous Western Provence, the Argens River drains in its lower lasted until 5000 BP, whereas in Western Provence, drier due to the watercourse large areas of the Maures and Esterel cristalline blocks Mistral wind, the first signs of the thinning of the forest occurred (fig. 1). earlier around 7500 BP. The Argens Delta (fig. 2) was built by continuous accretion of The slow decline of the deciduous forest after the Atlantic fine-grained sediments during the Holocene sea-level uprise (Dubar Optimum might have been be caused by independant factors, & Anthony, 1995; Dubar, 2003). The core of Pont d’Argens (fig. notably: 3) cuts through the upper 28 meters of these sediments which date — Morphodynamic modifications such as the uprise in sea-level from the 8000-3000 yr BP interval (Fiches et al., 1995). (closed to 1 cm/y) which primaraily determined the construction Palynological analysis has enabled us to produce a diagram with of the alluvial and coastal plain, and finally the edification of 148 52 superposed spectra (fig. 4). It comprises 33 arboreal taxa, 64 sand bars near the mouths and along the coasts. As a conse- herbaceous taxa and 21 taxa of ferns and mosses. quence of the modifications of landscape, environment and soils, The dominant taxa which are continously represented throu- the riparian forest and later the pine forest, became widespread ghout are the arborescent heather (30-50 %), deciduous oak (Dubar, 2001). (5-15 %) and pines (4-30 %). Quercus suber is very slightly represented (inf. 1 %), andCastanea is absent. — A global climatic tendency towards a cooling of the climate, The diagram shows three zones corresponding to an evolution linked to the solar radiation ratio (Berger, 1992) occurred after in three phases (fig. 4). the Atlantic Optimum. The first (from the basis to 21,5 m) indicates a stable compo- — The evolution of internal factors of the forest caused a slight sition of the vegetation, particularly for the deciduous trees (oak, imbalance in the geo-ecosystem (Heinrich & Hergt, 1993). lime). In this context of slow forest decline, Neolithic man probably The second phasis (from 21,5 m to the hiatus) starts with a con- took the opportunity to extend agro-pastoralism, precociously in tinuous curve of Alnus and with a peak of Corylus. Some heliophil- Western Provence, as indicated by the archaeological data, then ous plants (herbaceae, shrubs and pines) increased; correlatively the later in Eastern Provence. At Pont d’Argens, as in the whole of deciduous trees decreased significantely from about -19 m. Crystalline Provence, this scenario appears to have taken place The third phasis (from the hiatus to the top) marked a strong between the two at a date close to 6000 BP. The impact on the change: pines, Erica and other heliophilous plants are at the height forest cover will be however irreversible only much later, at the of representation when the deciduous oak drop at the minima. Iron Age (towards 3000 BP), everywhere in Provence (Triat-Laval, We note the curve of Alnus which certainly corresponds with a 1979) and in particular in Pont d’Argens. temporary expansion of the riparian forest. The flat but clear Abies curve also is observed on the other dia- grams of Provence (Beaulieu, 1977, Pichard, 1987, Nicol-Pichard & Dubar, 1998, Andrieu-Ponel et al., 2000). Besides, making use of these diagrams we can reconstitute the vegetation and its history in Crystalline Provence between 8000 and 3000 BP.

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auteurs, notamment Loisel (1976) qui envisageait un INTRODUCTION indigénat du châtaignier et considérait que les forêts de La végétation forestière actuelle de la Provence cristal- chêne-liège constituaient une large part des groupements line est essentiellement constituée par des groupements à sylvatiques potentiels de la basse Provence siliceuse. chêne-liège (Quercus suber L.), pin maritime (Pinus pinaster L’état originel de la végétation de cette Provence sili- Aiton subsp. pinaster), pin pignon (Pinus pinea L.) et châ- ceuse est donc encore mal connu. C’est pour cette raison taignier (Castanea sativa Miller). Le chêne vert Quercus( que l’étude pollinique d’une « archive sédimentaire » ilex L.), le chêne pubescent (Quercus pubescens Willd.) et le ayant conservé les pollens d’une période antérieure au pin d’Alep (Pinus halepensis Miller) sont nettement moins processus d’anthropisation nous a semblé intéressante fréquents. Ces taxons arborescents sont généralement à réaliser. Le carottage de Pont d’Argens est, en fait, le associés à des formations ligneuses plus ou moins basses premier enregistrement sédimentaire holocène provenant constituant le maquis et assez régulièrement parcourues du cœur même de la Provence cristalline entre les Maures par des incendies. Parmi les espèces les plus fréquentes et l’Esterel (fig. 1). du maquis, on peut citer la bruyère arborescente Erica( arborea L.), l’arbousier (Arbutus unedo L.), le cytise velu La carotte de Pont d’Argens (Cytisus villosus Pourret), le ciste de Montpellier (Cistus monspeliensis L.), le ciste à feuilles de sauge Cistus( sal- et son contexte géomorphologique 149 vifolius L.) et la lavande stéchas (Lavandula stoechas L.). L’Argens est un petit fleuve, long de moins de Cependant, comme l’avait noté Molinier (1954, 1973), 100 km qui prend sa source près de Saint-Maximin, sur le châtaignier paraît d’introduction récente et l’expan- le revers septentrional de la chaîne de la Sainte-Baume, sion du chêne-liège serait en grande partie liée à l’action en Provence occidentale (massif de Mourre d’Agnis). Il de l’homme. Ces points ont été contestés par certains rejoint la « dépression permienne » un peu avant Vidauban

Fig. 1. La Provence cristalline : socle magmatique et cristallophyllien, roches volcaniques des massifs des Maures, de l’Esterel et du Tanneron et leur auréole sédimentaire silicatée. Fig. 1. Siliceous Provence: basal complex of magmatic, metamorphic and volcanic rocks ot the Maures, Esterel and Tanneron blocks and their belt of silicated sediments.

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dans la ria, les sédiments apportés par l’Argens ont ainsi après avoir traversé une région de plateaux calcaires. Il provoqué son colmatage.Le colmatage est complet lors- ne quitte plus alors la zone des terrains silicatés, d’abord les pélites du Permien, puis la partie orientale du massif que le niveau de la mer s’est approché du zéro actuel et

cristallin des Maures. Son cours est donc situé, pour parts l’émersion a eu lieupeu après. sensiblement égales, en zone calcaire et en zone siliceuse. Les sédiments déposés présentent toujours une granu- Le delta lui-même a plus de 12 km de longueur et atteint lométrie fine et sont bien classés : ce sont des vases, des 5,5 km dans sa plus grande largeur. limons et des sables fins souvent chargés en débris orga- Réalisé dans la partie amont du delta (fig. 2), le son- niques (fig. 3, A). Au sommet, dans les derniers mètres, dage a atteint, à 28 m de profondeur, le substrat rocheux ces dépôts qui deviennent plus grossiers, graveleux et permien, après avoir traversé l’intégralité du remblaie- rougeâtres, résultent de phénomènes de ruissellement ou ment holocène présent en ce point. Ce remblaiement d’alluvionnement postérieurs à l’émersion. Trois dates s’est constitué au cours de la remontée postglaciaire du 14C ont été obtenues sur des lits tourbeux, niveau de la mer entre 12 000 ans BP, époque à laquelle dans le tiers inférieur de la carotte. Nous les utilisons en la mer était vers -100 m, et 3 000 ans BP, date à laquelle âge BP non calibré. La date de 7440 +/-90 BP (Ly 5868) ce niveau a atteint pratiquement le zéro actuel (Dubar & obtenue à 26,60 m permet de situer la base du remblaie- Anthony, 1995 ; Dubar, 2003). Les basses vallées sont ment vers 7 900 BP. Les dates intermédiaires sont de 150 alors ennoyées et transformées en rias (fig. 2). Piégés 7 080 +/-70 BP (Ly 5867) à 23,50 m, de 6 000+/-60

Fig. 2. Le delta de l’Argens et la position des deux carottages de Pont d’Argens et du Verteil. Fig. 2. The Argens delta: location of the two cores of Pont d’Argens and Verteil.

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l’intervalle 7 900-3 000 BP. Il manque malheureusement 5 m de sédiments, car la récupération des dépôts a été mauvaise entre -10 et -15 m.

L’analyse palynologique L’analyse a porté sur l’ensemble de la carotte, à l’ex- ception de la tranche 10 à 15 m. Ce hiatus ne semble toutefois pas avoir gravement affecté la continuité du diagramme pollinique. Normalement les analyses ont été réalisées avec un pas de 20 cm, mais parfois, afin de suivre les variations verticales de la lithologie, cet espacement a été modifié, ce qui explique une certaine irrégularité des prélèvements, en particulier dans les dix derniers mètres. Cette séquence supérieure est pauvre en pollens et les grains sont mal conservés. En revanche, dans la série sédimentaire infé- 151 rieure, qui se développe en-dessous de 15 m, les spectres sont très riches en pollens et spores. Le diagramme com- prend 52 spectres (fig. 4) qui ont permis d’identifier 33 taxons arborescents, 64 taxons herbacés, suffrutescents et cryptogamiques. Les pourcentages de ces derniers taxons ont été calculés séparément de façon à ne pas amoindrir la représentation globale du couvert forestier. La première colonne située à gauche du diagramme, montre les cour- bes respectives des pollens d’arbres (AP) et d’herbacées

Fig. 3. Les carottages de Pont (NAP). d’Argens (A) et du Verteil (B) Les familles des herbacées non représentées gra- et leur étalonnage C 14 (dates phiquement (tableau 1, p. 22) sont les Orchidaceae, BP non calibrées). Papaveraceae, Rutaceae, Saxifragaceae et Valerianaceae. Fig. 3. Pont d’Argens and Verteil cores with 14 C datings Les genres et espèces non représentés sont Aphyllanthes: (non calibrated BP). monspeliensis L., Crocus sp., Potentilla sp., Thalictrum sp. ainsi que Alisma sp., Hippuris vulgaris L., Lythrum sp., qui sont des plantes d’eau douce etRuppia sp. qui indique la présence d’eau saumâtre. Les trois essences dominantes et représentées de manière continue sont des Ericaceae (Erica arborea, 30 BP (Ly 5866) à 19,25 m et de 5790 +/-60 (Ly 5865) à à 40 %), des chênes caducifoliés (5 à 15 %) et des pins 18,60 m. La partie supérieure n’a pas été datée directe- (4 à 30 %). On remarque, en revanche, l’extrême discré- ment, cependant on peut évaluer son âge en se référant à tion (moins de 1 %) de Quercus suber qui est aujourd’hui un autre carottage réalisé plus en aval, au Verteil (fig. 1). caractéristique des massifs siliceux environnants. Erica Dans cette carotte, un petit lit tourbeux situé à -7 m arborea, qui domine constamment, a une fréquence rela- (fig. 3, B) a été daté de 3 050 BP (Ly 5889). Sans qu’on tivement homogène de la base au sommet (le hiatus de 5 puisse établir une parfaite correspondance altimétrique m entre les cotes 15 et 10 m ne produit pas de distorsion entre les deux carottages, il semble toutefois que le som- importante de sa représentation). met du remblaiement deltaïque de Pont d’Argens puisse Nous avons subdivisé le diagramme en trois zones être situé vers 3 000 BP. correspondant à une évolution triphasée (fig. 4) : Compte tenu de la genèse du remblaiement et de son — La première s’étend de la base jusqu’aux environs du caractère d’accrétion continue (Fiches et al., 1995), nous niveau 21,5 m. Les différentes représentations sont pouvons admettre que la carotte de Pont d’Argens couvre ecologia mediterranea, tome 30, fascicule 2, 2004, p. 147-157 ◆ M. DUBAR ET AL.

tendance significative d’une modification de la végétation. relativement stables. Les chênes caducifoliés se main- De même, la progression de Cistus et des chicorées peut tiennent à des valeurs élevées, immédiatement après être considérée comme étant liée à l’ouverture du milieu la bruyère arborescente. On peut noter la présence et à l’érosion probable des sols. pratiquement constante du tilleul (Tilia), espèce carac- La restitution de la végétation de la zone cristalline à téristique des milieux forestiers caducifoliés évolués. partir de l’étude palynologique de la carotte de Pont d’Ar- — La seconde zone lui succède jusqu’au hiatus. Elle est gens pose le problème de l’apport probable de pollens des assez hétérogène mais nous définissons sa base par la zones lointaines du bassin versant situées en Provence concomitance de l’apparition d’une courbe continue calcaire. Il semble cependant que ces apports soient rela- de l’aulne, d’un pic remarquable de Corylus et de tivement peu importants. En effet, la forte dominance, l’accroissement des Cichorioideae. Cette zone peut en nombre de grains, d’Erica arborea, qui est une espèce être subdivisée elle-même en deux sous-zones 2a et calcifuge réputée pour ne diffuser ses pollens qu’à très 2b : la première de 21,5 m jusqu’à 17,5 m, la seconde faible distance, tend à montrer que la composition polli- de 17,5 m jusqu’au hiatus. Ces deux sous-zones se nique des spectres est principalement d’origine locale. Ce différencient au niveau du fonds arboréen : la pre- cortège paraît donc relativement bien représentatif de la mière voit la persistance d’une bonne représentation flore de la zone cristalline proche du carottage. de taxons arborescents forestiers comme les chênes à 152 feuillage caduc et le sapin (Abies), la seconde partie est caractérisée par la nette diminution de ces arbres, tandis que les héliophiles comme les Cichorioideae, les Chenopodiaceae et Pinus prennent de l’importance. DISCUSSION Le rapport AP/NAP diminue corrélativement. Couvrant une durée de près de 5 millénaires, le — La troisième couvre la partie supérieure du diagramme. diagramme de Pont d’Argens montre l’évolution de la Les taux de Pinus, d’Erica arborea et des héliophiles végétation holocène régionale. Il peut être comparé aux sont à leur apogée, tandis que ceux des chênes sont à autres diagrammes obtenus en Provence comme ceux de leur minimum. Tourves (Nicol-Pichard, 1987) et de Biot (Nicol-Pichard & Dubar, 1998). Le premier est situé en Provence calcaire Bien développée entre 21 et 17,40 m avec un pic de à l’ouest de Pont d’Argens, tandis que le second, localisé 40 % à 17,80 m, la courbe de l’aulne (Alnus) est certaine- en région niçoise également calcaire, est plus à l’est. Ces ment représentative de l’essor momentané de la ripisylve. deux diagrammes montrent le développement considé- La discrète courbe du sapin (Abies) entre 21 et 18 m rable de la forêt mésophile, tout particulièrement de la est bien conforme à ce qui est connu par ailleurs en chênaie caducifoliée dès l’Holocène ancien. Ce type de Provence pour cette période (Beaulieu, 1977 ; Triat- végétation paraît d’ailleurs constituer un état d’équilibre Laval, 1978, Pichard, 1987 ; Nicol-Pichard & Dubar, durable dans toute la Provence, Provence occidentale et 1998 ; Andrieu-Ponel et al., 2000) et dénote sans doute rhodanienne comprises (Triat-Laval, 1979) ainsi que dans l’existence de sapinières dans des massifs voisins du bas- le Sud des Alpes (Beaulieu, 1977) : la reconquête de la sin de l’Argens. En effet, la présence de grains de pollens forêt depuis la fin du glaciaire est rapide et continue et conduit à l’optimum atlantique entre 8 000 et 7 500 BP. de sapin au faible pouvoir dispersif (Triat-Laval, 1971) En Provence cristalline, sur les roches mères compactes implique l’existence régionale d’arbres producteurs. (granites, rhyolithes, gneiss), assez peu altérables sous Les herbacées ne présentent pas de variations significa- climat méditerranéen, les facteurs édaphiques sont forte- tives, on note cependant une légère progression des NAP ment exprimés, certainement en raison de la chimie des à partir de la cote -17,50 m. Dès cet instant, la courbe sols, mais aussi vraisemblablement dans le faible dévelop- de l’aulne s’arrête et celle des fougères progresse consi- pement des profils. De ce fait, les espèces de la chênaie dérablement. Ce changement voit aussi l’accroissement caducifoliée sont localement peu favorisées par rapport de la courbe des pins et la diminution de celle du chêne à d’autres taxons qui, commeErica arborea, sont moins pubescent. Ces tendances se confirment après le hiatus exigeants au point de vue édaphique. Dans ce complexe (cote -10 m) et semblent donc bien valider les résultats du chêne caducifolié et de la bruyère arborescente, il est de cette deuxième partie du diagramme. Les variations évidemment difficile de savoir si la répartition végétale qui y sont observées, en particulier la progression des se faisait selon une mosaïque de zones (par exemple des pins et celle de Erica arborea, s’inscrivent bien dans une

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Fig. 4. Diagramme pollinique de Pont d’Argens (les taxons trop rares n’ont pas été portés sur le diagramme ; voir texte). Fig. 4. Pollinic diagram of Pont d’Argens (taxa very rare were not related to the diagram ; see text).

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taxons altitude Croc Aphymons MAL ORC PAP PRI Thal Filip RUT SAX Viola Lythr Alism Hipp Rupp VAL 542 1,50 769 0,80 860 1,70 901 0,80 0,80 0,80 925 0,80 0,80 0,80 980 1,00 1,00 1,00 1610 1650 0,20 1705 0,50 1720 0,40 1740 0,20 0,40 1760 154 1780 0,50 1,20 0,90 1820 0,30 0,60 1900 0,20 1923 0,30 1960 0,50 2020 0,20 2060 0,30 0,30 2080 0,20 0,20 2170 0,30 0,30 2310 0,30 2330 0,70 2390 0,30 2410 0,30 2470 0,30 2490 0,20 0,20 2530 0,30 2550 0,30 2650 0,30 2670 0,20 0,20 2690 0,40 0,40 2707 altitude taxons Croc Aphymons MAL ORC PAP PRI Thal Filip RUT SAX Viola Lythr Alism Hipp Rupp VAL

Croc = Crocus ; Aphymons = Aphyllanthes monspeliensis ; MAL = MALVACEAE ; ORC = ORCHIDACEAE ; PAP = PAPAVERACEAE ; PRI = PRIMULACEAE ; Thal = Thalictrum ; Filip = Filipendula ; RUT = RUTACEAE ; SAX = SAXIFRAGACEAE ; Lythr = Lythrum ; Alism = Alisma ; Hipp = Hippuris ; Rupp = Ruppia ; VAL = VALERIANACEAE

Tableau 1. Contenu du variadu diagramme pollinique (figure 4). Table 1. Detailed content of thevaria in the polllinic diagram (figure 4).

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que pourrait être aussi le résultat de changements morpho- groupements à bruyère dominante sur les adrets et les dynamiques locaux. En effet, tout particulièrement dans sols superficiels et des secteurs plus forestiers à chênes les basses vallées ou à proximité du rivage, il a été montré pubescents sur les ubacs et les sols profonds) ou bien si que sous l’effet de la remontée du niveau marin (Dubar, une véritable association chêne-bruyère occupait l’ensem- 2001), vers la fin de la transgression holocène, à partir de ble des massifs. Un faciès de ce type existe aujourd’hui 6 000 BP, la formation des plaines alluviales côtières et dans certaines zones protégées, non perturbées par les des basses vallées conduit à l’extension des ripisylves puis incendies depuis plus de cinquante ans, comme la haute à celle des pinèdes au détriment de la chênaie. L’extension vallée du Reyran dans le massif de l’Esterel. Mais toutes tardive des pins sur la frange côtière et près des estuaires les observations écologiques montrent que la bruyère est essentiellement d’ordre édaphique et liée à la mise en régresse lorsqu’elle est dominée par des ligneux de taille place, alors que le niveau marin s’est presque stabilisé, des supérieure. La coexistence de ces deux taxons avait déjà cordons sableux et graveleux (Dubar & Anthony, 1995). été observée par Reille (1984), à basse altitude en Corse, Ce phénomène est très perceptible sur le diagramme de avec des taux élevés de pollen d’Erica arborea dès le Biot (Nicol-Pichard & Dubar, 1998), mais il l’est moins début de l’Atlantique, ce qui avait conduit cet auteur à sur celui du Pont d’Argens. s’interroger sur la place de la bruyère arborescente dans Des variations climatiques au cours de l’Holocène, les écosystèmes naturels sur terrains siliceux. On peut après l’optimum atlantique, ont également été invoquées remarquer que, en Corse, des taux relativement élevés pour expliquer les changements de végétation. Depuis la de cette espèce ont été relevés à des altitudes approchant 155 1 800 m (Reille, 1975), ce qui conduit à penser que son fin du glaciaire, la tendance linéaire a été au réchauffe- pollen est relativement diffusable par le vent. Quoi qu’il ment jusqu’à l’optimum climatique atlantique. Un lent en soit, cette végétation à l’architecture mal connue, cons- rafraîchissement aurait suivi, provoqué par des change- tituée globalement de chênes caducifoliés et de bruyères ments de l’insolation terrestre (Berger, 1992). Certains arborescentes semble représenter un certain état de sta- auteurs font intervenir des « crises » climatiques. Ainsi, la bilité (climax), qui peut être dit « originel », c’est-à-dire détérioration du Subboréal correspondrait à l’accomplis- antérieur à l’anthropisation. sement d’une série modulée de phases sèches à caractère « méditerranéen » accusé (Jalutet al., 2000). Cependant Sur le diagramme de Pont d’Argens, comme d’ailleurs l’origine de ces crises climatiques et même leur réalité sur les autres séries polliniques de Provence orientale, physique restent hypothétiques. l’intervention de l’homme néolithique semble plus faible On a également fait appel à la dynamique interne et plus tardive qu’en Provence occidentale, peut-être des écosystèmes, sans qu’il n’y ait aucune intervention discrètement vers 6 500 BP, au début de la phase 2, où externe. Après la reconquête rapide post-glaciaire et le pic de Corylus peut être, lui aussi, interprété comme l’acmé de l’optimum atlantique (Kremer & Petit, 2001), une ouverture ménagée du milieu qui profite momen- la chênaie caducifoliée décline lentement comme cela tanément à cette héliophile mésophile. L’ouverture du est fréquent dans la dynamique des populations. Les paysage est nettement plus sensible dans la seconde causes peuvent être multiples, mais il semble que pour partie de cette phase où le pic des Chenopodiaceae peut les communautés végétales à extension très rapide, des représenter l’extension des rudérales ou bien l’installation rétroactions positives, cumulatives et durables pour- d’une végétation lagunaire halophile. Cependant, le pic raient s’établir, menant à un certain déséquilibre du géo- des Cichorioideae et la régression des taxons forestiers, écosystème (Heinrich & Hergt, 1993). notamment avec la disparition de Tilia,fait pencher pour Il n’est pas possible de faire la part respective de ces la première hypothèse. L’anthropisation s’accentue forte- divers éléments. Seul le constat d’une évolution forestière ment dans la dernière phase, qui semble correspondre au est certain et cette évolution se fait, à l’Atlantique, dans Bronze final et à l’âge du Fer, d’après l’âge de 3 000 BP le sens d’une diminution sensible du couvert mésophile, obtenu sur le carottage du Verteil. Les pollens de pins le changement étant diachrone : atteignent des taux inégalés, ainsi que la bruyère dans — En Provence occidentale et rhodanienne, au climat le niveau supérieur, alors que les cistes, comme tous les plus sec et soumis à l’action du mistral, le changement taxons héliophiles (Artemisia, Helianthemum, Plantago, enregistré par les archives polliniques est plus précoce. Apiaceae, Cichorioideae, Chenopodiaceae, etc.) sont en On observe notamment les premières manifestations forte augmentation ; Calluna, Asphodeluset Juniperus sont et fluctuations des chênaies sclérophylles à partir de des indicateurs de pastoralisme. 7 500 BP, date qui coïncide avec l’installation des pre- La lente régression de la forêt après l’optimum atlanti- ecologia mediterranea, tome 30, fascicule 2, 2004, p. 147-157 ◆ M. DUBAR ET AL.

mières communautés néolithiques du Cardial ancien environ 7 500 BP, la dominance (attendue) de certains (Triat-Laval, 1978). taxons comme la bruyère arborescente, le rôle impor- — En Provence la plus orientale (au-delà du Tanneron), tant de la chênaie caducifoliée et l’absence de taxons, plus humide car subissant l’influence du relief des aujourd’hui prépondérants, comme le chêne-liège ou le Alpes, l’équilibre mésophile de la forêt de la période châtaignier. Sur le plan de l’évolution de la couverture atlantique paraît se maintenir pratiquement jusque végétale de la Provence cristalline au cours de l’Holocène, vers 5 000 BP (Dubar et al., 1986). ce diagramme est conforme à ce qui est déjà connu en Provence calcaire. La tendance forestière mésophile est On peut émettre l’hypothèse que la Provence orientale exprimée précocement (c’est la suite normale de l’évo- bien que occupée sur son littoral dès 7 000 BP (Binder & lution climatique postglaciaire), modulée par les facteurs Maggi, 2001) a été plus faiblement et plus tardivement édaphiques locaux. Des signes de modifications d’origine mise en exploitation que la Provence occidentale (Dubar anthropique ou à déterminisme naturel apparaissent à & Roscian, 2001). En retour, l’impact sur le couvert partir de 6 500 BP, avec un décalage d’un millier d’an- végétal est aggravé également de manière retardée dans nées par rapport aux données obtenues en Provence le temps. Il ne faut cependant pas oublier que les diffé- occidentale, et donc, chronologiquement intermédiaires rences climatiques peuvent aussi jouer sur l’expression avec ceux observés en zone calcaire orientale. À partir 156 pollinique du degré d’anthropisation. À Pont d’Argens, de 5 500 BP, les manifestations d’une exploitation par la situation paraît être intermédiaire avec l’enregistrement l’homme producteur deviennent évidentes pour aboutir d’une première régression de la chênaie caducifoliée vers à une anthropisation généralisée vers 3 000 BP. 6 500 BP suivie d’une accentuation à partir de 5 500 BP. L’impact reste cependant modéré et la dégradation ne deviendra irréversible que beaucoup plus tard, vers 3 000 BP. On doit remarquer que ces données polliniques mon- REMERCIEMENTS trent la grande rareté du chêne-liègeQuercus ( suber) et L’interprétation palynologique et la rédaction de l’absence du châtaignier (Castanea sativa), tous deux forts l’article ont bénéficié des nombreux conseils de Michel pollinisateurs, qui sont aujourd’hui les arbres caractéristi- Girard. Qu’il en soit vivement remercié ici. Nous remer- ques des massifs des Maures et de l’Esterel. Par contre, la cions également Claudine Dauphin pour la traduction discrétion de l’arbousier (Arbutus) dans le diagramme est en anglais de la version abrégée ainsi que les deux rap- peut être à mettre au compte de sa faible dispersion polli- porteurs anonymes qui ont contribué à éclairer certains nique. Comme en zones calcaires, la chênaie caducifoliée points importants de la discussion. constituait l’essentiel de la forêt originelle et, de la même façon que pour ces régions, les données phytohistoriques s’inscrivent en faux vis-à-vis des spéculations phytoso- ciologiques. Ces dernières accordaient, pour les massifs siliceux, une place prépondérante soit au chêne vert (Molinier, 1973), soit au chêne-liège (Lavagne & Moutte, Bibliographie 1974 ; Loisel, 1976). L’absence du châtaignier rend égale- ANDRIEU-PONEL V. , PONEL P. , JULL A.J.T, BEAULIEU J.-L., ment peu probable un indigénat suggéré par l’individuali- BRUNETON H. & LEVEAU P., 2000. Towards the reconstruc- sation actuelle d’une association végétale particulière dans tion of the Holocene vegetation history of Lower Provence: les massifs des Maures et de l’Esterel (Loisel, 1976). two new pollen profiles from Marais des Baux.Veget. Hist. Archeobot., 9: 71-84.

BEAULIEU J.-L. DE, 1977. Contribution pollenalytique à l’histoire tardi- et post-glaciaire de la végétation des Alpes méridiona- les françaises. Thèse ès-sciences Aix-Marseille III, 358 p. CONCLUSION BERGER A., 1992. Le climat de la Terre. Un passé pour quel avenir ? Le diagramme de Pont d’Argens offre une première Editions De Boeck-Wesmael. 479 p. approche phytohistorique de la Provence cristalline anté- BINDER D. & MAGGI R., 2001. Le Néolithique ancien de l’arc rieure à l’intervention de l’homme néolithique. Il nous liguro-provençal.Bull. Soc. Préhist. Fr., 98 : 411-422. renseigne sur la composition de la végétation depuis DUBAR M. & ROSCIAN S., 2000. Scénario climatique et dévelop-

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pement de l’agro-pastoralisme néolithique en Provence et en LAVAGNE A. & MOUTTE P., 1974. Feuille de Saint Tropez au Ligurie. Bull. Soc. Préhist. Fr., 98 : 391-398. 1/100 000. Bull. Carte Végét. de la Provence et des Alpes du DUBAR M., 2001. Évolution de la végétation littorale en relation Sud (I) : 3-43. avec les changements physiographiques et édaphiques à la fin LOISEL R., 1976. La végétation de l’étage méditerranéen dans de la transgression holocène en Provence orientale (France). le sud-est continental français.Thèse ès-sciences Aix- Actes du XVIIe Congrès de l’APLF, Arles, sept. 2001, 38. Marseille III, 384 p. DUBAR M., 2003. The Holocene deltas of Eastern Provence and MOLINIER R., 1954. Les climax côtiers de la Méditerranée occi- the French Riviera : geomorphological inheritance, genesis dentale, Vegetatio, 4 : 284-308. and vulnerability. Géomorphologie: relief, processus, environne- MOLINIER R., 1973. Les études phytosociologiques en Provence ment, 2003, 4: 263-270. cristalline, Bull. Hist. Nat. Marseille, 33 : 7-46. D UBAR M. & ANTHONY E.J., 1995. Holocene Environmental NICOL-PICHARD S. & DUBAR M., 1998. Reconstruction of Late- Change and River-Mouth Sedimentation in the Baie des Glacial and Holocene environments in Southeast France Anges, French Riviera.Quatern. Res. 43, 3: 329-343. based on the study of a 66 m long core from Biot, Alpes- DUBAR M., DAMBLON F. , NICOL-PICHARD S., VERNET J.-L., Maritimes. Veget. Hist. and Archeobot., 7 :11-15. CHAIX L., IRR F. & BABINOT J.-F., 1986. L’environnement REILLE M., 1975. Contribution pollenanalytique à l’histoire tar- côtier des Alpes-Maritimes à la fin de la transgression versi- diglaciaire et holocène de la végétation de la montagne corse. lienne d’après l’étude biostratigraphique du site de l’Etoile à Thèse ès-sciences Aix-Marseille III, 206 p. Nice (France). Revue de Paléobiologie, 5 : 289-310. 157 REILLE M., 1984. Origine de la végétation de la Corse sud- FICHES J.-L, BÉRATO J., BRENTCHALOV D., CHOUQUER G., orientale ; analyse pollinique de cinq marais côtiers. Pollen et DUBAR M., GAZEENBEEK M., LATOUR J. & ROGERS B., spores, 26 (1) : 43-60. 1995. Habitats de l’Age du fer et structures agraires d’épo- TRIAT-LAVAL H., 1971. Contribution à l’étude de la dissémina- que romaine aux Escaravatiers (Puget-sur-Argens, France). tion pollinique du pin, du hêtre, du sapin et de l’épicéa. Ann. Gallia, 52 : 205-262. Univ. de Provence, Sciences,46, p. 155-160. HEINRICH D. & HERGT M., 1993. Atlas de l’Ecologie. Encyclopédie TRIAT-LAVAL H., 1978. Contribution pollenalytique à l’histoire d’aujourd’hui. Le Livre de poche, Paris, 286 p. tardi- et post-glaciaire de la végétation de la basse vallée du JALUT G., AMAT A.E., BONNET L., GAUQUELIN T. & Rhône. Thèse ès-sciences Aix-Marseille III, 343 p. FONTUGNE M., 2000. Holocene climatic changes in the TRIAT-LAVAL H., 1979. Histoire de la forêt provençale depuis 15 Western Mediterranea, from South-east Spain. Palaeogeogr., 000 ans d’après l’analyse pollinique. Forêt médit., 1 : 19-24. Palaeoclim., Palaeoecol., 160 : 255-290.

KREMER A. & PETIT R., 2001. L’épopée des chênes européens. La Recherche, 342 : 40-43.

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Distribution and stand structure ofTaxus baccata populations in Greece; Results of the first national inventory Distribution et structure des peuplements de Taxus baccata en Grèce ; résultats du premier inventaire national

K. Kassioumis1, K. Papageorgiou1, T. Glezakos2 & I.N. Vogiatzakis3 1. Correspondence author: NAGREF – Agricultural Research Station of Ioannina (ARSI), E. Antistasis 1, Katsikas, 45500, Ioannina, Greece. E-mail: [email protected] 2. NAGREF – Information and Documentation Section, Egialias 19 & Chalepa, 15125 Athens, Greece 3. Landscape and Landform Research Group Department of Geography, University of Reading Whiteknights RG6 6AB, Reading Berks, UK 159

Abstract Résumé Yew, Taxus baccata L. is a declining species that occupies a limited L’if, Taxus baccata L., est une espèce en déclin qui occupe un espace range throughout the Mediterranean basin. The community struc- limité dans le bassin méditerranéen. La structure des peuplements ture and spatial distribution of yew trees were investigated in Greece et la répartition spatiale des ifs ont été étudiées en Grèce au moyen by means of a questionnaire survey administered to Forest District d’une enquête sous forme de questionnaire adressé aux bureaux Offices nationwide. The results of the survey show that the species forestiers nationaux. Les résultats de l’enquête montrent que l’espèce population is confined mainly to mountainous areas extending est confinée principalement dans les zones montagneuses s’étendant from south Peloponnese to Evros prefecture. Findings suggest yew du Péloponnèse sud à la préfecture d’Evros en Thrace. Les résultats as a rare and potentially endangered species that occurs at different suggèrent de considérer l’if comme une espèce rare et potentielle- degrees of population fragmentation ranging from individual trees ment en danger dont les populations se situent à différents degrés to more rarely clumps of trees. Yew distribution is formed by isolated de fragmentation, allant de spécimens isolés à, plus rarement, des populations, mostly in mountain ravines at an altitudinal range petits boisements. La répartition de l’if en Grèce est donc constituée between 500 and 1 500 metres; it increasingly becomes an isolated de populations isolées, principalement dans les ravins de montagne, storey tree within fir pure forests Abies( cephalonica) and various à une altitude comprise entre 500 et 1 500 m ; il se rencontre de kinds of mixed woodlands of beech and oak, as well as mixed forests plus en plus comme une espèce de sous-étage, isolée dans les forêts of fir and beech. Populations are small, most in shrubby groups of de sapin (Abies cephalonica) et dans différents types de forêts 5 to 50 individuals with height ranging between 3 and 6 metres mélangées de hêtre et de chêne, ainsi que dans des forêts mélangées and low proportion of saplings and seedlings. The rarity of yew de sapin et de hêtre. Les populations sont petites, la plupart en populations and biochemical interest implicate the adoption of groupes de 5 à 50 individus d’une hauteur de 3 à 6 m avec une appropriate management actions to facilitate broader expansion, faible proportion d’arbres et de jeunes plants. La grande rareté aiming at restoring existing Taxus woodland areas and increasing des populations d’if et l’intérêt biochimique impliquent l’adoption the share of Taxus forests under statutory protection within the d’actions appropriées de gestion visant à faciliter une expansion de Natura 2000 network of protected areas. l’espèce, afin de reconstituer les zones sylvestres existantes àTaxus et d’augmenter la part de forêts de Taxus sous la protection statutaire Key-words du réseau Natura 2000. Yew tree, Taxus, yew forests, questionnaire survey, Greece Mots-clés If, Taxus, forêts d’if, enquête, Grèce

ecologia mediterranea, tome 30, fascicule 2, 2004, p. 159-170 ◆ K. KASSIOUMIS, K. PAPAGEORGIOU, T. GLEZAKOS & I. N. VOGIATZAKIS

trees within larger forests and to a lesser extent in small groups (Voliotis, 1986). Taxus baccata has a stress-tole- NTRODUCTION I rant life strategy sensu Grime, being slow growing, slow The contribution of the Holarctic or Eurasiatic element to reach maturity (70 years), long lived (> 1 000 years), in the Mediterranean flora and its importance to the post shade tolerant but can withstand full sun (Thomas & glacial flora of Southern Europe and North Africa has Polwart, 2003). It is also of high ornamental value and often been highlighted (see review in Quézel, 1985). sometimes in Greece is planted in parks and gardens Ye w, Taxus baccata L. is one of the species belonging to (Christopoulos & Bastias, 1990). this element of pre-Miocene origin that now occupies a The seeds and foliage of Taxus baccata contain the limited range not only in the Mediterranean basin but all alkaloid taxin (Vidakovic, 1991), a compound that exhibits over Europe (Ellenberg, 1988; Thomas & Polwart, 2003). significant anticancer properties. The biochemical interest The distribution of the species in the Mediterranean of taxanes and fear of extinction in Greece has been a Basin includes the North Mediterranean countries (Euro- major influence for increasing managerial interest for the Mediterranean) (Jalas & Suominen, 1973; Di Benedetto woodland species of Taxus .However, until now there has et al., 1983; Barbero & Quézel, 1994; Quézel & Médail, never been an attempt to carry out a detailed inventory 2003), Morocco, Algeria and Turkey (Hulten & Fries, about the spatial distribution andecological characteristics 1986). Yew is at present confined to mountainous areas of the species in the country. For example Voliotis (1986), 160 of the basin, following the climatic regression after the last Strid (1980; 1986) as well as Boratynskiet al. (1992) refer ice age (Garcia et al., 2000). Palaeoecological evidence to the distribution and limited ecological information of from various sites in the Mediterranean suggest that yew the species. The plant population of the Taxusspecies is contributed a significant amount of tree pollen during the not precisely known. Population estimates are rare and Holocene indicating that it was a co-dominant element in usually not accurate. Moreoverthe conservation status of the vegetation formations at the time (Grove & Rackhan, Taxus baccata is inadequate in Greece. Only two habitat 2001; Goni & Hannon, 1999; Penalba, 1994). This has types that include Taxus baccata have been identified as made yew a reliable indicator for ancient temperate priority habitat types, according to habitats’ directive 92/ forests (Barbero & Quézel, 1994). Today yew grows 43/EEC (Dafis et al., 1997), and limited information can sparsely along the Mediterranean basin and does not be derived on how well the network of protected areas correspond to the places it used to occupy millions years conserves yew forests in Greece. ago (Charles, 1982). Large population ofTaxus can still The above realisations set out the demand to undertake be found in northern Spain and Italy but the majority of a nation-wide survey aiming at firstly, acquiring a natural yew woods are fragmented and isolated (Quézel better knowledge of the geographical distribution and & Médail, 2003). topographical conditions of the existing populations of Despite its decline in Europe with few exceptions Taxus baccata in Greece and secondly analysing major (see Svenning & Magard, 1999) it is currently acknowl- community structure parameters of native forests. edged there is a lack of information on the species Furthermore, based on the knowledge of natural distri- distribution and abundance all over Europe including bution and community structure, the research sets out a the Mediterranean area (IPGRI, 2003). This is also the framework of management actions to aid conservation case of Greece, where the information about the species and improve its management. distribution is fragmented despite the fact that numerous accounts of the species can be found in a number of floristic surveys (Dimadis, 1916; Voliotis & Athanasiadis, 1971; Boratynski et al., 1990) Taxus baccata is a native species in Greece; woodlands grow dispersed in its native habitat in deciduous or mixed RESEARCH METHODOLOGY forests on mountain slopes and in ravines (Christensen, 1997). They are notable on limestone and grow from an The need for building up a national inventory in elevation of 800 m up to a maximum limit of 2 200 m, conjunction with the sporadic occurrence of yew in reaching a height of 10-20m in maturity (Athanasiadis, Greece, prohibits the use of random survey plot sampling 1986; Tutin et al., 1993; Arampatzis, 1998). As a result along transects, on account of the increased cost, workload of climate change and human disturbance over centuries, and time required. The nature of the research implies the yew distribution is more frequently formed by individual use of a specially designed questionnaire targeting forest experts employed in Forest District Offices, as the most

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its own district. Four major subject areas were covered to appropriate survey instrument to collect nationwide acquire information about (i) the geographical distribution information for a dispersed species regarding its major of yew populations; (ii) major climatic and topographical biophysical parameters. Forest District Office (FDO) is conditions; (iii) ownership status and habitat structure of the statutory forest authority for each of the 104 forest native forests; and (iv) the stand structure characteristics districts divided in Greece, responsible for managing and of Taxus baccata. Following the questionnaire analysis, a conserving forest resources. The questionnaire layout thorough procedure of personal communication between aimed to facilitate filling in time, to help the respondents members of the research team and forest experts was answer all questions with the highest consistency level and initiated, in order to clarify information and identify to assist with coding and subsequent statistical analysis. It possible cause of yew decline. In addition, on-site visits was deemed imperative from the onset of the research, to were carried out to illuminate all non-clear situations. The reduce the unit of analysis from a surface area to a single nomenclature and classification of the taxa mentioned are point location due to the scarcity and relative rarity of yew according to Flora Europaea (Tutin et al., 1993). trees. Each competent Forest District Office completed a separate questionnaire for each yew population, either in Data were collected from a systematic postal survey the form of a single tree or clump of trees, found within carried out between July and December 1995. Forest

161

Figure 1. Geographical distribution of Taxus baccata in Greece: 1) (●) found by this study and 2) (--) reported by Voliotis (1986).

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162

Figure 2. Distribution of Taxus baccata according to major climatic and topographical parameters.

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Figure 3. Ownership status and structure of forests including Taxus baccata. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 159-170 ◆ K. KASSIOUMIS, K. PAPAGEORGIOU, T. GLEZAKOS & I. N. VOGIATZAKIS

experts were asked to complete the questionnaire and areas of central and northern Greece, especially along return it in the attached pre-paid envelope. In addition, the Pindos mountain range, the mount Olympus, the telephone communication with forest experts, helped Rodopi mountain range and the mount Cholomontas in explaining the research scope and served as a persuasive the peninsula of Halkidiki. Further, small natural stands measure to stimulate participation. Overall, 104 question- of yew are found in the Peloponnese and in the island naires were distributed to all Forest District Offices and of Evia. Individual yew trees are widespread in several a usable data set of 103 questionnaires was eventually locations throughout the country. Aggregate data suggest collected and used in the analysis representing a response that yew populations are found in 28 out of the 51 pre- rate of 99 %, which ensured a nationwide data coverage. fectures of Greece. The high response rate obtained is similar to that repor- ted by Pantera & Papanastasis (2003) concerning the inventory of Valonia Oak in Greece and can therefore Climatic and topographical conditions be regarded as a normal average for a field study of this Research findings indicate that Taxus baccata in kind. Of the 103 Forest District Offices, 42 (40.78 %) Greece occurs in a broad elevational range from sea provided information for the occurrence of yew forests level to over 1 500 m high (fig. 2a), but it is primarily within their administrative region; no yew woodlands a montane tree with most populations growing in 501- 164 were identified for the remaining 61 units (59.22 %). In 1 000 m (49.09 %) and 1 001-1 500 m altitude range total, the research gathered information on 117 forests (41.82 %). Eighteen sites (10.4 %) are found in low alti- containing 173 locations of Taxus baccata. Response rate tudes (< 500 m) and only five sites (2.89 %) are found at in each question varies from a low rate of 79.2 % to as an altitude above 1 500 m. Within this altitudinal range, high as 100 % indicating that overall, forest respondents yew tends to grow on the north-eastern (60.13 %) and had a satisfying knowledge of the biophysical and phy- siographic parameters of yew populations. north-western (20.89 %) slopes where there is high humi- Based on the information obtained from questionnai- dity and high insolation. Stands of yew thrive on slopes res, an inventory form was created for everyTaxus baccata of almost any inclination but they were primarily found location identified, as shown in the appendix. A special on moderate slopes (57.5 %), less on even surfaces and information system was developed to facilitate analysis slopes less than 40 % (26.25 %) and only 16.25 % on and interpretation of the results using the inventory forms moderate to steep slopes (> 71 %). Furthermore, ravines as input information source. The information system is are the most common habitat for yew populations. Of essentially an electronic data bank to allow immediate the 127 locations reported, 78.74 % were found to grow access and management of the information as well as on ravines, 16.54 % on smooth mountainsides and only to update the results with new records. The programme 4.72 % on steep cliffs. According to the bioclimatic types dBase IV ver. 2.0 for DOS was used as the platform for identified for Greece by Mavromatis (1980), the vast developing the data bank. It provided advanced options majority of yew sites (74.75 %) generally occur in the for data management and the possibility to transferred sub-Mediterranean zone (40>x>0; x= number of biolo- data to Microsoft Access and edit results in various kinds gical dry days during dry period, according to the method of format, whether in print or electronically. of Bagnouls-Gaussen) and 20.23 % in the low-mid- Mediterranean (75>x>40). In addition, only 3.47 % of the identified sites belong in intense mid-Mediterranean (100>x>75) and a tiny 1.73 % of the sites occur in non- arid type (x=0). Taxus baccata populations are typically RESULTS associated with limestone substrate (46.67 %). They also tend to grow well upon schist (33.94 %) and with lower Geographical distribution frequency occurrence on flysch (21.82 %). Shallow soil of Taxus baccata depth was rarely limiting; most yew stands grow on shallow (38.16 %) and medium soils (36.64 %) and only This survey provided information of the geographical occasionally on medium-deep (13.74 %) and deep soil occurrence of yew locations as well as of the distribution depth (11.45 %). This is expected as yew is renowned of various stand sizes across the country. The occurrences for having an extensive horizontal root system (Rodwell, mapped in figure 1 give the best information available. 1991). Large yew populations are confined in mountainous

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165

Figure 4. Community structure of yew populations.

Ownership status and structure Yew sites are almost equally encountered in pure of native habitat (45.30 %) and mixed (52.00 %) forests and rarely on The research findings indicate that 173 sites contain partially forested areas (1.71 %). This reflects that yew Taxus baccata populations, which are distributed along saplings are favoured by more sheltered, shady and moist 117 different forests nationwide. Most yew populations locations. In pure stands, yew forms part of an understory occur in state owned forests (65.0 %), followed by of conifers being especially prominent in fir forestsAbies ( municipal forests (19.13 %) as shown in figure 3a. This cephalonica) (71.7 %) and very occasionally in Black is not of surprise if one bears in mind that two thirds of pine (Pinus nigra) (11.32 %), Beech (13.2 %) or Oak the forest area in Greece is public land (65 %) and the (3.77 %, largely Quercus frainetto) stands. In the Fagion remaining 35 % is shared by all other non state own- alliance, yew occurs in the Luzulo-Fagetum woodlands ers (Papageorgiou et al., 2004). There are only 3 yew especially alongside the Pindus range, in theAsperulo- populations (2.61 %) under private ownership while in Fagetum in central and northern Macedonia and in the 12.17 % of the reported yew sites, the ownership status Cephalanthero-Fagion in Mount Olympus (Dafis et al., remains unclear. 1997). In mixed forests occurrence is less selective. Yew ecologia mediterranea, tome 30, fascicule 2, 2004, p. 159-170 ◆ K. KASSIOUMIS, K. PAPAGEORGIOU, T. GLEZAKOS & I. N. VOGIATZAKIS

trees can be found more frequently in mixed Oak-Beech yew occurs most frequently in the undergrowth reaching a stands (23.08 %), Fir-Beech (17,95 %), Fir-Black pine height between 3 and 5 m (73.02 %). Only 17.06 % of the (15.38 %) and occasionally in Beech-Fir (7.69 %) and trees have a low canopy of 6-10 m in height and in 8.31 % Oak-Fir/Black pine (5.98 %) stands. Owing to its extreme of the identified sites, individuals have exceeded 11 m hei- tolerance of shade, yew grows up to form a shrub layer, ght. The bell-shaped form of yew distribution, according to when scattered and occasionally a part of the canopy girth, indicates that most of the yew populations recorded in denser populations. Figure 3e shows that most yew are represented by individuals in medium diameter classes populations are found in the understory (56.49 %), less (49.1 % in 11-20 cm and 42.23 % in 21-50 cm). There are only a few specimens of yew with a girth below 11cm usually in the middle layer (24.43 %), and only 9 sites and above 50 cm. The paucity of individuals in the lowest (6.87 %) have been recorded to contain yew trees as an girth class is a survey weakness; forest experts could not associate in the canopy. Yew seldom forms a true shrub provide accurately information on saplings and seedlings layer and is usually intermingled with various Juniperus and emphasized particularly on the largest individuals. species (29.8 %) and Ilex aquifolium(29.8 %). Other Although limited numeric data is available to judge yew frequently encountered species are Ostrya carpinifolia recolonization, the questionnaire sought to describe the (14.9 %), Carpinus orientalis(10.6 %) and Quercus ilex general state of regeneration in yew populations. Findings (10.6 %) with occasional Acer pseudoplatanus, Corylus suggest poor yew regeneration in the identified populations 166 avellana and various Ulmus species (4.2 %). with replacement of individual trees occurring only in 21 out of the 108 yew locations (19.44 %). Community structure Based on the data for all juvenile and mature Taxus trees Figure 4 depicts a variety of parameters to illustrate recorded, the information system estimated the total number the stand structure of yew trees in Greece and give an of Taxus baccata trees throughout the country to be about indication of the scarcity of the species. The study revea- 9,000 individuals (recorded data for 9,070 trees). However, led that populations are rather small, most between 5-50 the figure is likely to be an underestimate given that infor- individuals (48.56 %), or exist in scattered patches of 2-4 mation of new recruitments and seedlings could not be trees (13.29 %) and more frequently in isolated specimens adequately documented by the questionnaire survey. (23.7 %). Large yew stands are rare, only 12.13 % of the identified sites contain populations between 51 and 500 individuals while dense stands (over 500 trees) are for- med in only 2.31 % sites. The area each yew community DISCUSSION covers was found to vary in proportion to stand size. Thus with the exception of single-tree sites, most populations The present study has made explicit that the use are found to occupy a land area of 0,2-1 ha (56.88 %) of a questionnaire survey to build aTaxus inventory and less frequently extending to 1,1-5 ha (27.52 %). allows only a macroscopic evaluation of major structural Following the rarity of large yew stands, only 13 popula- parameters pertaining to the natural distribution of yew tions (11.93 %) extent to an area greater than 5 ha. The forests in Greece. Despite the methodological inadequa- largely scattered and small isolated populations impede cies, the questionnaire survey remains a useful instrument yew to develop progressively into pure yew forests. It can for providing baseline information on the geographical be inferred from the above, that population fragmentation and topographic distribution, population dynamics and constitutes the major cause for the degeneration of the the community structure of yew trees at a country level. species in Greece. This is verified by communication with Such information could provide a significant insight the forest experts who also suggested indiscriminate fel- into the conservation potential of the species and set a ling and to a lesser extent grazing, as other less significant broad framework of actions to improve its management causes of yew decline. and conservation. This study provides a comprehensive account of the current state of the species in Greece and Growth of yew is slow compared to most other trees considers how forestry practices might be adjusted. even under optimum conditions. Consequently, even the oldest individuals do not attain considerable height. The survey provided a measure of height and girth for each The state of Taxus baccata in Greece recorded individual. For groups we recorded the number Foremost, Taxus baccata is fairly rare and never found of trees in each height and girth class. In Greek forests, in a large quantity; it occurs at different degrees of

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been further impeded by herbivory. The research implies population fragmentation ranging from individual trees to an apparent regeneration failure of most yew populations more rarely clumps of trees. Indeed, consistent with other in Greece. Communication with forest experts indicated researchers (Voliotis, 1986), this study has confirmed that grazing as a potential factor in lack of recruitment but yew grows naturally in high mountains of central and factual evidence is lacking to substantiate the above northern Greece but some disparities are also apparent. assertion. Instead, the weakness of the questionnaire Voliotis (1986) reported Taxus baccata growing naturally survey to provide an accurate record of seedlings and in the islands of Thassos, Samothraki, south of Evia and saplings, may be a more plausible explanation. in forests in central and southeastern Peloponnese that are not verified by the present study. However, small natu- ral stands of yew that extend further east, in the Evros Implications for conservation prefecture and in the Sithonia peninsula were reported by this study. and management Based on research findings, most yew populations in Currently, there is minimal forestry importance for the Greece are restricted to north-eastern, ravines in medium woodland species of Taxus baccata in Greece, apart from steep slopes at an altitudinal range between 500 and the spiritual value of particularly old and large individuals 1 500 m. Taxus baccata increasingly becomes an isolated in churchyards (Strid, 1980). Forest management today understory tree within fir pure forests Abies( cephalonica) aims explicitly at the foresighted sustainable timber yield 167 and various kinds of mixed woodlands, most notably in of the species with the most economic importance and deciduous mixed stands of beech and oak, mixed conifer management plan is the main planning tool. Hence, no stands of fir (Abies cephalonica) and black pine (Pinus separate management plans have been conducted for nigra) as well as mixed forests of fir and beech. Perhaps yew populations and no concrete actions are prescribed a major finding of the research is the marked structural in the plans drawn for forests with Taxusin order to homogeneity of yew stands. The adult population preserve the integrity of yew populations. However, structure is skewed towards small isolated shrubby groups the importance of T. baccata as an alternative source of of 5 to 50 individuals having a height range between 3 taxoid production (Appendino et al., 1992), has brought and 6 m. Large and dense stands of yew trees are rare forward the scientific interest for the conservation of the with most trees forming small groups or being scattered species. There is, at present, increasing research on the individually within forests throughout the country. The anticancer properties of taxanes isolated from yew trees occurrence of such small isolated populations has been (Guéritte, 2001). Originally extracted from the bark of a common status along the Mediterranean basin. For the Pacific yew (T. brevifolia), taxol (paclitaxel) can now instance, Garcia et al. (2000) noted that in southern be synthesized from a taxol congener 10-deacetylbaccatin Spain, T. baccata is restricted to a small number of III) which can be extracted at approximately 10 times the isolated patches, most with fewer than 10-20 individuals quantity per unit weight from the leaves ofTaxus baccata dominated by senescent individuals with a low proportion and other Taxus species than from Taxus brevifolia bark of saplings and seedlings. Thomas and Polwart (2003) (Dennis, 1988). In Greece, yew belongs to the group of report a similar situation in Portugal and the islands of rare and potentially endangered species on account of a Corsica and Sardinia. number of causes, most notably its highly fragmented It has been often pointed out by many authors (e.g. geographical distribution followed by indiscriminate Thomas & Polwart, 2003) that accounting for the felling of mature trees. The largely small and scattered distribution of the species is a difficult task. Apart from populations restrict yew to evolve gradually into denser climate change considered to be responsible for the stands. Anzalone et al. (1997) noted that the rarity of species decline, particularly in the Mediterranean area, Taxus in the Mediterranean flora of southern Europe may there are also other factors that have been put forward. be due to the yew being left as a declining relict as the These include its poor competitive ability with respect to climate has become less oceanic. Consequently, in the light if compared to other species that grow together with face of predicted climate change, it seems likely that yew yew such as hornbeam and beech and its extermination populations in Greece will further deplete. by shepherds/farmers since it was poisonous to animals The fringe occurrence and biochemical interest of (Ellenberg 1988). Although in exceptional circumstances Taxus baccata yield certain managerial implications for high regeneration has been reported (e.g. Garciaet al., the forest authorities. Most importantly, the restoration of 2000), in general, the opposite is the case with regeneration Taxus woodland areas could be alleviated through applied ecologia mediterranea, tome 30, fascicule 2, 2004, p. 159-170 ◆ K. KASSIOUMIS, K. PAPAGEORGIOU, T. GLEZAKOS & I. N. VOGIATZAKIS

management and possibilities of increasing the area of ACKNOWLEGEMENTS habitat types. Population viability management methods should be restricted to the few dense stands identified by The General Secretariat for Research and Technology the survey. Appropriate silvicultural manipulation needs of the Greek Ministry of Development for supporting to be applied to include a management by thinning to let this research within the framework of a wider project in more light and help regeneration. In the multiplicity to study the pharmaceutical biosynthesis of Taxol. We of remaining yew locations that include a few number of thank D. Trakolis from the Forest Research Institute individuals, usually grown in the understory of pure or of Thessaloniki and F. Galanos from the Institute of mixed forests, management should attempt to facilitate Mediterranean Forest Ecosystems and FPT in Athens for their valuable help in communicating with Forest District yew recolonization by creating more gaps. This approach Offices and verifying the data on the inventory form for is more likely to increase the possibility of survival of several sites with Taxus baccata trees. yew populations and expand tree number. However, individual trees are found more difficult to evolve into a forest community and success is a function of favourable biotic and abiotic conditions (Carvalho et al., 1999). 168 Applied management interventions should be followed References up by policy reforms such as changes in the forest legislation to prohibit yew cutting, in order to stimulate ANZALONE, B., LATTANZI, E., LUCCHESE, F. & PADULA, M. 1997. The vascular flora of the Circeo national park. Webbia, 51: protection of yew individuals against indiscriminate 251-341. felling in managed forests. Also the underpinning of APPENDINO, G., 1993. Taxol (paclitaxel): historical and ecological state forest ownership prevalence for the management aspects. Fitoterapia, 1: 5-24. and restoration of Taxus baccata populations should not APPENDINO, G., GARIBOLDI, P., PISETTA, A., BOMBARDELI, be underestimated. It can be a supportive factor in the E. & GABETTA, B., 1992. Taxanes fromTaxus baccata. sense that integrated, comprehensive and explicit forest Phytochemistry, 31: 4253-4257. management actions can be evenly applied to two-thirds ARAMPATZIS, TH., 1998. Shrubs and trees of Greece, vol. I. of the country’s forestland. Technological and Educational Institute of Drama. Drama. Another implication concerns the conservation of 322 p. (in Greek).

the species, especially in relation to national parks and ATHANASIADIS, N., 1986. Forest Phytosociology. Aristotle other protected areas. Granting to yew woodlands a sta- University of Thessaloniki, Thessaloniki. 309 p. (in Greek). tutory protection could improve the population viability BARBERO, M. & QUÉZEL, P., 1994. Place, rôle et valeur historique primarily as a virtue of cessation of grazing and human des éléments laurifoliés dans les végétations préforestières et disturbance. Currently, the conservation status ofTaxus forestières ouest-méditerranéennes.Annali di Botanica, 52: baccata is deficient in Greece. Despite the classification 81-133. of the habitats “Mixed beech forests with Taxusand BORATYNSKI, BRAWICZ, K. & ZIELINSKI, J., 1992. Chorology Ilex” and “Mountainous coniferous woods withTa x u s of Trees and Shrubs in Greece. Polish Academy of Sciences, baccata” (92/43/EEC codes 9120 and 9580 respectively) Kormik. 286 p. as priority habitat types (Dafiset al., 1997), only twelve CARVALHO, A., REBELO, A. & DIAS, J. 1999. Distribution and representative sites (4,05 %) accounting for an area of natural regeneration of yew trees in the national parks of Peneda-Geres (Portugal) and Baixa Limia Serra-Xures 3,717 ha or 0,16 % of the total proposed protected land, (Spain). Revista de Biologia, 17: 43-49. contain Taxus woodlands. Moreover, with the exception CHARLES, J.-P., 1982. Etude climatique, floristique et statistique of a national park (Mt. Olympus) and a protected natural des peuplements d’ifs (Taxus baccata L.) du sud de la France monument (Mt Voras peaks), which provide strict statu- (Provence, Languedoc, Corse). Thèse de doctorat dee cycle,3 tory protection, all remaining sites are hunting reserves université d’Aix-Marseille III, Marseille, 226 p. with a rather ambiguous conservation potential. Thus, CHRISTENSEN, K.I., 1997. Taxus L. In: TRIDS , A., & TAN, K. increasing the share of forests including Taxusunder a (ed), Flora hellenica vol 1. Koeltz Scientific Books,Königstein : statutory protection regime is believed to aid broader p. 15. expansion of yew in Greece. CHRISTOPOULOS, G. & BASTIAS, I., 1990. Phytologia. Ekdotiki Athinon, Athens. 435 p. (in Greek).

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DAFIS, S., PAPASTERGIADOU, E., GEORGIOU, K., BABALONAS, PAPAGEORGIOU K., VAKROU, A. TRAKOLIS, D. & MALAMIDES, D., GEORGIADIS, TH., PAPAGEORGIOU, M., LAZARIDOU, TH. G., 2004. Sustainable Forest Management: The challenge ahead & TSIAOUSI, B., 1997. Habitat Directive 92/43/EEC. Ecotypes for the Greek State Forestry. In: Humphreys, D. (Ed) Forests in Greece: Natura 2000 network. Gen. Directorate XI EC, for the future: findings on National Forest Programmes Goulandri Natural History Museum, EKBY, Thessaloniki. from COST Action E19, European Science Foundation 923 p. (in press).

DENNIS, J.N., 1988. A highly efficient, practical approach to PENALBA, M.C. 1994. The history of the Holocene vegetation in natural taxol. J. Am. Ch. Soc., August 1988: 5917. northern Spain from pollen analysis. J. Ecol., 82: 815-832. DI BENEDETTO, L., LEONARDI, S. & POLI, E., 1983. Taxus baccata QUÉZEL, P., 1985. Definition of the Mediterranean region and L. in Sicilia. Not. Fitosoc., 18: 1-18. the origins of the flora. In: Gomez-Campo, C. (Ed)Plant DIMADIS. D., 1916. Forest vegetation of Greece. National Printing Conservation in the Mediterranean Area. (ed. C.), Dordrecht, Office of Greece, Athens. 159 p. pp. 9-24. ELLENBERG, H., 1988. Vegetation ecology of central Europe. QUÉZEL, P. & MÉDAIL, F., 2003. Ecologie et biogéographie des forêts Cambridge University Press, Cambridge, UK. du bassin méditerranéen. Elsevier, Paris, 573 p. GARCIA, D., ZAMORA, R., HODAR, J.A., GOMEZ, J.M. & CASTRO, RODWELL, J.S., 1991.British plant communities, vol. 1. Woodlands J., 2000. Yew (Taxus baccata L.) regeneration is facilitated by and scrub. Cambridge University Press, UK. fleshy-fruited shurbs in Mediterranean environments.Biol. STRID, A., 1980. Plants of Mt. Olympus. Goulandri Natural Conserv., 95: 31-38. History Museum, Athens. 420 p. 169 GONI, M.F.S. & HANNON, G.E., 1999. High altitude vegetational STRID, A., 1986. Mountain Flora of Greece. Vol. 1. Cambridge pattern on the Iberian Mountain chain (north-central Spain) University Press, Cambridge. 822 p. during the Holocene. The Holocene, 9: 39-57. SVENNING, J.C. & MAGARD, E., 1999. Population ecology and GROVE, A.T. & RACKHAM, O., 2001. The Nature of the conservation status of the last natural population of English Mediterranean Europe. Yale University Press, New Haven. yew Taxus baccata. Denmark. Biol. Conserv., 88: 173-182. GUÉRITTE, F., 2001. General and recent aspects of the chemisttry THOMAS, P.A., & POLWART, A., 2003. Taxus baccata L. J. Ecol., and strucutre-activity relationships of taxoids.Cur. Pharm. 91: 489-524. Des., 7: 1229-1249. TUTIN, T.G., BURGES, N.A., CHATER, A.O., EDMONDSON, J.R., HULTEN, E. & FRIES, M., 1986. Atlas of north European vascu- HEYWOOD, V.H., MOORE, D.M., VALENTINE, D.H. WALTERS, lar plants: north of the tropic of cancer I-III. Koeltz Scientific S.M. & WEBB, D.A., 1993.Flora Europaea, 5 vol. Cambridge Books, Königstein. University Press, London. IPGRI, 2003. EUFORGEN www.ipgri.cgiar.org/networks/ VIDAKOVIC, M., 1991. Conifers: morphology and variation. euforgen/. Graficki Zavod Hrvatske, Zagreb. JALAS, J. & SUOMINEN, J., 1973. Atlas Florae Europaeae: distribution VOLIOTIS, D., 1986. Historical and environmental significance of of vascular plants in Europe. Vol. II Gymnospermae (Pinaceae the yew (Taxus baccata L.). Isr. J. Bot., 35: 47-52. to Ephedraceae). VOLIOTIS, D. & ATHANASIADIS, N., 1971. Trees and shrubs. MAVROMATIS, G., 1980. Bioclimate of Greece; correlating Thessaloniki. 294 p. climate and natural vegetation, bioclimatic maps.For. Res., 1: 54-63. (in Greek). PANTERA, A. & PAPANASTASIS, V.P., 2003. Inventory of Valonia oak (Quercus ithaburensis Decaisne subsp. macrolepis (Kotschy) Hedge & Yalt. in Greece.Geot. Sc. Iss., 14: 34-44.

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APPENDIX

Inventory form of the Taxus baccata populations in Greece Location code number:

Prefecture’s name, land area (Ha) and forest area (Ha) Forest District Office’s name and category Characteristics of forests with Taxus trees — name of the forest — municipality (where the forest belongs to) — ownership status (state, private, municipal, monasteries, other) — forest structure (pure forest – one main species –, mixed, partially forested area) — silvicultural type (high forests, coppice, high and coppice) — dominant tree species (in pure forests) — dominant tree species (in mixed forests) — other tree species present in the forest Characteristics of sites with Taxus trees 170 — name of the site — altitude above sea level (m) (< 500 m, 501-1 000 m, 1 001-2 000 m, > 2 000 m) — bioclimatic character (based on Mavromatis, G. 1980) — site exposure (orientation) (east-southeast, south-southwest, north-northeast, west-northwest) — soil slopes (%) (< 40 %, 41-70 %, 71-100 %, > 100 %) — bedrock (limestone, flysch, schist, other): — soil depth (non-deep < 50 cm, mean depth 51-100 cm, deep > 1m) Growth conditions of Taxus populations — population density (only 1 tree, 2-4 trees, 5-20, 21-50, 51-100, over 100 trees) — spread of Taxus trees in the forest (in single trees, in groups, in thickets, in clumps) — covered area (Ha) — participation in the structure of the forest (in the upper layer, in the middle layer, in the understory) — distribution of Taxus trees (along streams, on smooth mountainsides, on steep sides) — general appearance (excellent, good, fair, poor) — existence of regeneration (yes, no) Characteristics of Taxus trees — breast diameter (cm) (< 5 cm, 6-10 cm, 11-20 cm, 21-50 cm, > 50 cm) — height (m) (< 2 m, 3-5 m, 6-10 m, 11-20 m, over 20 m)

Geographical location of the site (on a map scale 1/50 000) and also information on how to approach the site and contact persons.

ecologia mediterranea, tome 30, fascicule 2, 2004 Comparing the palatability of Mediterranean or non-native plants in Crete Étude comparative de la palatabilité de végétaux méditerranéens ou exotiques en Crète

Carsten F. Dormann1, Rachel King2 1. Applied Landscape Ecology, UFZ Centre for Environmental Research Leipzig-Halle, Permoserstr. 15, 04318 Leipzig, Germany. Email: [email protected]. Tel: ++44-(0)341-235 2953 – Fax: ++44-(0)341-235 2511 2. Scott Wilson, Scott House, Basing View, Basingstoke, RG21 4JG, UK 171

Abstract Résumé Herbivory is thought to be an important factor in the ecology of L’herbivorie est connue comme étant un facteur important interve- introduced species. A lower palatability to the herbivores may con- nant dans l’écologie des espèces introduites. Une faible palatabilité tribute to the success of invasive species in their new habitat. Here vis-à-vis des herbivores est susceptible de contribuer au succès des we investigate the palatability (to the generalist herbivore snail espèces invasives dans leur nouvel habitat. Dans ce travail, nous Cepaea hortensis) of 11 non-native plant species found on Crete avons étudié la palatabilité (vis-à-vis d’un gastéropode herbivore et and compare it to that of 13 native species. These were collected généraliste Cepaea hortensis) de 11 espèces végétales introduites en from three different habitats (dunes, olive groves and shrublands), Crète et nous l’avons comparée à celle de 13 espèces végétales indigè- so as to be able to reconstruct a community background palatability. nes. Ces espèces sont issues de trois catégories d’habitats (dunes, oli- Our results indicate that non-natives fall into the range of palatabi- veraies et matorrals), de façon à permettre une reconstruction de la lities found among the natives, with no significant overall difference palatabilité à l’échelle de la communauté. Nos résultats indiquent between these groups. In all three tested habitats, non-natives were que la palatabilité des espèces introduites s’insère dans la gamme more palatable than the native community background. Only in de palatabilité rencontrée chez les espèces indigènes, sans différence dunes was one non-native species,Acacia saligna, markedly less significative globale entre les deux groupes. Toutefois, pour chacun palatable than the community average. Palatability of the species des trois habitats testés, la palatabilité des espèces introduites s’est was not related to their commonness on Crete, independent of being avérée plus élevée que la palatabilité moyenne à l’échelle de la native or not. communauté. Une seule espèce introduite, Acacia saligna, présente dans les formations dunaires, est apparue comme nettement moins appétante que la moyenne de la communauté. La palatabilité des Key-words espèces n’est pas reliée à leur abondance en Crète, que l’espèce soit Alien species, Cepaea hortensis, community palatability, Crete, indigène ou introduite. dune, herbivory, Mediterranean island, olive-grove, shrubland Mots-clés Espèces introduites, Cepaea hortensis, palatabilité des communautés, Crète, dune, herbivorie, île de Méditerranée, oliveraie, matorral

ecologia mediterranea, tome 30, fascicule 2, 2004, p. 171-178 ◆ C. F. DORMANN & R. KING

Crete have a lower palatability to generalists than natives. INTRODUCTION The richness of the local flora, its many island endemics and the numerous non-native plant species present on Biological invasions of natural communities by the island make Crete an island of high invasion risk non-native plant species is one of the most serious (Vitousek, 1988). Two of the selected habitats (dunes and threats to biodiversity (Heywood, 1995), especially shrublands) are important communities for rare species, in Mediterranean-type ecosystems (Huenneke, 1988; while the third (recently abandoned olive groves) repre- Vitousek, 1988). The extend to which introduced spe- sents the anthropogenic habitat most commonly invaded cies become established, and later become pests, differs by non-native species (Lonsdale, 1999). widely (Williamson & Fitter, 1996; Williamson, 1999), and seems to be a function of both species traits (“inva- siveness”) and community susceptibility (“invasibility”: Alpert et al., 2000). One of the interfaces between invasiveness and ETHODS invasibility is the interaction between non-native plants M and their herbivores. It has been argued that palatability The study was performed on Crete, Greece (35.5° N differences allow non-native plant species to become 25° E) from 10 to 20 May 2002. Ten sites were selected 172 invaders (Blossey & Nötzold, 1995). This would imply for each of three habitat types: olive grove, coastal dune that grazers, browsers and plant parasites are important and phrygana (the arid dwarf-shrubland frequent in the in controlling the invasion process (Noble, 1989). eastern Mediterranean). In each site, cover of the most Anti-herbivore chemistry of the non-native may be common plant species and all those used in this study very different from that of the natives (often helped by the were recorded. Non-native species occurred in none of fact that the non-natives are recruited from families new the plots chosen for the recordings, because they usually to the community, Rejmánek, 1996). Thus, they present produce monodominant stands within the investigated a novel suite of feeding deterrents to the local herbivores, communities. which make them more effective in their defence against the consumers (it has even been argued that co-evolu- tion between plants and their consumers is the cause of Sampling procedure the diverse secondary metabolism found in plants, see and bioassay-palatability trial Harborne, 1997; Hartley & Jones, 1997, for review). To Ca. 10 g leaf material of 13 typical common native a generalist herbivore, which is confronted with different and 11 common non-native plant species (table 1) was defence cocktails in each plant species, such differences collected near the above sites. The five replicates for each are probably less important, as it is far less engaged in co- plant species were several km apart. Within eight hours evolution with its forage than a monophagous specialist. extracts were prepared following Grime et al. (1993): 1 g To date, very little information on the palatability of fresh leaf material was ground in 10 ml H non-native plant species compared to that of the local 2Odist., filtered natives is available (Crawleyet al., 1996; Williamson & through Whatman #1 filter paper and then frozen until Fitter, 1996). More work has concentrated on related further use. topics, such as comparing the performance of a non- Palatability trials were run according to (Grime et al., native invader in its native and its new range (Callaway 1993): the test was a comparison between 0.18 ml extract and Aschehoug, 2000; Bossdorf et al., 2004) or the effect on a 1.5 cm × 1.5 cm piece of Whatman #1 filter paper of herbivory on exotic and indigenous congeneric species (added in three doses) and filter paper without extract. (e.g. Schierenbeck et al., 1994, e.g. Radford & Cousens, These filter papers were dried at 30 °C in a drying oven 2000). These studies however did not take account of the and then weighed to the nearest mg. Both filter papers background palatability of native species when addressing were re-wetted with equal amounts of water just before the effect of herbivory on the establishment of a non- offering them to the snails. Pre-trials have shown that native. snails eat the moist filter paper. After the trial, the filter In this study, we report on a bioassay-palatability trial paper was left to dry again and then re-weighed. Each comparing 11 non-native and 13 native plant species sample extract was fed to two different snails (i.e. two common to three habitats on the Greek island of Crete. subsamples per replicate). We hypothesis that invasive introduced plant species on As a bioassay agent for palatability, some 50Cepaea hortensis garden snails were collected. Grime et al.

ecologia mediterranea, tome 30, fascicule 2, 2004 COMPARING THE PALATABILITY OF NATIVE AND NON-NATIVE MEDITERRANEAN PLANTS ◆

Native Non-native

Ammophila arenaria, Poaceae (Aa) Acacia saligna, Fabaceae (As)

Calicotome villosa, Fabaceae (Cv) Agave americana, Agavaceae, (Ag)

Ceratonia siliqua, Fabaceae (Cs) Ailanthus altissima, Simaroubaceae (Aia)

Cupressus sempervirens,Cupressaceae(Cu) Arundo donax, Poaceae (Ad)

Forb mixture from the undergrowth (F) Carpobrotus acinaciformis, Aizoaceae (Ca)

Medicago marina, Fabaceae (Mm) Nicotiana glauca, Solanaceae (Ng) Table 1. Native and non-native species sampled (abbrevia Olea europaea, Oleaceae (Oe) Opuntia ficus-indica, Cactaceae (Of) tions).

Otanthus maritimus, Asteraceae (Om) Oxalis pes-caprae, Oxalidaceae (Op)

Pancratium maritimum, Amaryllidaceae (Pm) Phytolacca americana, Phytolaccaceae (Pa)

Quercus coccifera, Fagaceae (Qc) Ricinus communis, Euphorbiaceae (Rc)

Sarcopoterium spinosum, Rosaceae (Ss) Robinia pseudoacacia, Fabaceae (Rp) Thymus capitatus, Lamiaceae (Tc) 173 Urginea maritima, Liliaceae (Um)

June and 7th July 2002. Air temperature during the fee- (1993) used the species Cepaea nemoralis, which is rare ding period was recorded at half-hourly intervals. in Scotland (Kerney, 1976). We selectedC. hortensis not A palatability index was calculated as the preference only because it is an accepted generalist herbivore (Grime for extract over control per total amount eaten: et al., 1993), but also because all plant species tested are PI ranges from Ð1 to +1, with negative values indica- unknown to the snails. Thus, there was no ‘native’ plant ting rejection of extract compared to water. The nonlinear species in the palatability trial from the snails’ perspective. index used by Grime et al. (1993) = extract eaten/control Hence, no bias with respect to coevolution was introdu- eaten) is not sensible when very little of the control or ced. This could have led to a false representation of the extract sample has been eaten, as it produces a bias in general palatability of that species. Moreover, most larger favour of high index values (which can be cured by the snails in the cultivated areas of Crete are in fact non-native taking the logarithm of the ratio Elstonet al., 1996). Using (e.g. Helix aspera), being imported from the mainland the same index (but calling it “acceptability index”), (Francisco Welter-Schultes, personal communication). Dirzo (1980) had to discard those trials where the test By focussing solely on the palatability of water-soluble disk has been rejected or where control disks were con- leaf content, we disregard the importance of leaf tough- sumed less than half (although stating that these tests are ness, hairiness, etc. As dozens of different herbivores are a valid measure of acceptability). This was the case in consuming the plants (sheep, goat, different species of some of our trials. However, their index is related to ours snails, beetles and bugs), it is impossible to test for specific by the formula: palatability to all these herbivores. We therefore resorted to only investigate water-extractable leaf content, which will be consumed by all these leaf herbivores. Species distribution data The individually marked snails were kept in a cage under near-natural conditions until used for the trial. For The data for the species’ distribution on Crete were this, they were starved for 24 h, then put together with the taken from Turland (1992) and Turland et al. (1993). extract and the control filter paper in a moist plastic bowl They mapped all species in a 8.25 km × 8.25 km grid. and left for 16 h overnight. After the trial snails were fed We used the number of occupied cells as an index of on lettuce for two days before the starving for the next distribution. trial. Each snail was used approx. five times for different plant species extracts. No snail received the same com- Statistical analysis bination of plant species, and sequences of plant species were randomised. Feeding trials took place between 11th Arcsin (0.1* square-root (x+1)) transformed data from the feeding trials were analysed with a mixed effect ecologia mediterranea, tome 30, fascicule 2, 2004, p. 171-178 ◆ C. F. DORMANN & R. KING

model (function “lme” in R: Pinheiro and Bates; 2000), as had values of PIolive grove = Ð0.407, PIphrygana = Ð0.499 subsamples were nested within replicates. ‘Status’ (native and PIdune = Ð0.265. Apart from the dunes, non-native or non-native) was used as the fixed effect and ‘species’ palatability was always higher than this background as a random effect, since we were not interested in the level. Only in the dunes did the PI-value of the introdu- specific identity, but rather in the difference between ced Acacia saligna indicate lower palatability than that of native and non-native. ‘Temperature at time of feeding’, the native community (see fig. 1). Palatability and cover ‘woodiness of the species’ and ‘snail weight’ (as well as all for native species was unrelated in all three habitats interactions) were used as additional explanatory varia- (Pearson’s correlation: P > 0.3 for all three habitats). bles, but were excluded from the final model as their The species also differ widely in their distribution on contributions were far from significant (P > 0.4, model Crete as measured by the number of occupied grid cells. simplification following suggestions of Crawley 2002). This was, however, not related to their palatability (fig. 3). While non-natives were overall less common than natives (F 1, 21 = 11.32, P < 0.01), palatability was unrelated to distribution for both types (F1, 21 = 0.01, P = 0.93). RESULTS 174 Species differed widely in their palatability to snails (fig. 1). However, our hypothesis, that native and intro- DISCUSSION duced species differ in their palatability to a generalist herbivore was not confirmed. They did not differ signifi- In this comparison of the palatability of 13 native and

cantly in their palatability (fig. 2; F1, 22 = 2.12, P= 0.160; 11 non-native Cretan plant species we could not detect log-ratios produced the same results). a difference using a generalist herbivore as a bioassay. In Within habitats, we compared the palatability of all fact, non-natives were even slightly more palatable than non-native species to that of the natives occurring in natives (although not significantly so: fig. 2). We therefore this habitat, weighted by their abundance according to have to conclude that there is no a priori reason to believe our vegetation recordings. This background palatability that the ‘nativeness’ status of a species has any relevance

Fig. 1. Palatability sequence of the tested 24 species. Positive values indicate preference of extract over water. Abbreviations as in table 1.

ecologia mediterranea, tome 30, fascicule 2, 2004 COMPARING THE PALATABILITY OF NATIVE AND NON-NATIVE MEDITERRANEAN PLANTS ◆

filter paper control. However, these trials were performed on fresh material, not extracts, and are thus not directly comparable to our situation. Comparing the palatability of non-natives not only to that of natives, but more specifically to common native species within a given habitat has not been attempted before. Given that non-natives are slightly more pala- table than natives, it is not surprising to find that the background PI-values are also generally more negative, i.e. natives are less palatable. The exception ofAcacia saligna (syn. Acacia cyanophylla) in the dunes is remar- kable, as this species is a pest in South Africa (Roux & Middlemiss, 1963) and became invasive more recently in western Mediterranean coastal dunes (Cronk &Fuller, 1995). Investigations into this coincidence of high com- munity background palatability and low palatability of Acacia saligna may be fruitful. As for the other species, it 175 Fig. 2. Palatability of natives compared to non-natives. is remarkable that the species with the highest palatability, Ricinus communis or Castor Oil Plant, ironically has seeds highly toxic to mammals (ricin leads to the agglutination for the probability of generalist herbivores limiting its of red blood cells). This high toxicity does not hold for success at establishment in a given habitat. Consistent leaves and snails, apparently, as none of them died in the with this finding, there was no relationship between pala- weeks following the experiments. tability and distribution of the species on Crete. Our study does not address palatability to specialist Palatability is related to a plant’s growth rate (Herms & herbivores, therefore an extrapolation to the effect of her- Mattson, 1992). Faster growing species allocate less assi- bivory per se on the establishment of non-native species milates to anti-herbivore defense, thus being more pala- is not possible. Possibly species that suffer heavily from table (Hartley & Jones, 1997, Jones & Hartley, 1999). a native specialist herbivore might evolve higher compe- titive performance in its absence (the EICA hypothesis: Blossey & Nötzold, 1995; Keane & Crawley, 2002), which is based on the ideas of Herms and Mattson (1992). A test of this coevolutionary hypothesis is beyond the scope of this study. Palatability values measured by our experiments showed a greater variability than those given by Dirzo (1980) and Grime et al. (1993). In these two studies, (converted) PI values for water extracts of grasses and dicotyledons are usually in the range of 0 to Ð0.15 (Grime et al., 1993). For plants where cell sap was known to be distasteful, PI values went down to Ð0.33, but clearly neither above 0 nor below Ð0.5, as was the case in our experiment. This is probably a consequence of their rejection of trials where only control material was consumed, biasing against low palatability. In another palatability experiment, when simultaneously offering 43 species to a snail and a cric- ket, consumption data show clear rejections (i.e. PI values of Ð1) for 24 and 10 species, respectively (Grimeet al., 1996). Moreover, since filter paper ranking 12th in the list, snails consumed less of 73 % of all species than of the Fig. 3. Distribution of the 24 species on Crete was unrelated to palatability. Grey dots refer to non-natives, black dots to natives. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 171-178 ◆ C. F. DORMANN & R. KING

176

ecologia mediterranea, tome 30, fascicule 2, 2004 COMPARING THE PALATABILITY OF NATIVE AND NON-NATIVE MEDITERRANEAN PLANTS ◆

However we have no data for the species tested in this study, and a recent review found no supportive evidence References for the hypothesis that non-natives have higher growth ALPERT, P., E. BONE & C. HOLZAPFEL, 2000. Invasiveness, inva- rates than natives (Daehler, 2003). Nevertheless, it may sibility and the role of environmental stress in the spread of be that our specific selection of non-natives is indeed more non-native plants.Persp. Plant Ecol. Evol. Syst. 3, 52-66. palatable because the have a higher growth rate. BLOSSEY, B. & R. NÖTZOLD, 1995. Evolution of increased com- Another trait of the foliage that reduces consumption petitive ability in invasive nonindigenous plants: a hypothesis. is leaf and tissue toughness. As we produced extracts, J. Ecol. 83, 887-889. we did not test this trait, but it may play an important BOSSDORF, O., S. SCHRÖDER, D. PRATI & H. AUGE, 2004. role in the field. Sclerophylly is very common in woody Palatability and tolerance to simulated herbivory in native Mediterranean plant species, due to the ecophysiologi- and introduced populations of garlic mustard (Alliaria petio- cal constraints of the climate (Larcher, 1995) and the lata). Am. J. Bot. 91, 856-862. deterrent effect of tough leaves on herbivores (Davidson, CALLAWAY, R. M. & E. T. ASCHEHOUG, 2000. Invasive plants 1993). This holds true as much for the native Ammophila( versus their new and old neighbors: a mechanim for exotic arenaria, Ceratonia siliqua, Cupressus sempervirens, Olea invasion. Science 290, 521-523. europaea, Quercus coccifera and Thymus capitatus) as for CRAWLEY, M. J., 2002. Statistical Computing: An Introduction to the non-native species in this experiment (Acacia sali- Data Analysis using S-Plus. Wiley, New York. 177 gna, Agave americana, Arundo donax, Nicotiana glauca and CRAWLEY, M. J., P. H. HARVEY & A. PURVIS, 1996. Comparative Opuntia ficus-indica). ecology of the native and alien floras of the British Isles. The Cretan landscape has been subject to intense Philos. Trans. R. Soc. Lond. Ser. B 351, 1251-1259. grazing by livestock for centuries (Rackham & Moody, CRONK, Q. C. B. & J. L. FULLER, 1995. Plant Invaders. Chapman 1996). Those plants now present must therefore have & Hall, London. adapted to this situation. As additional winter feeding DAEHLER, C. C., 2003. Performance comparisons of co- keeps livestock densities usually well above the popula- occurring native and alien invasive plants: implications for tion density supported by the vegetation alone, one could conservation and restoration. Annu. Rev. Ecol. Evol. Syst. 34, assume the plants are accustomed to very high levels of 183-211. grazing. Hence new plant species are more likely to come DAVIDSON, D. W., 1993. The effects of herbivory and granivory from habitats with lower grazing intensity. For a generalist on terrestrial plant succession.Oikos 68, 23-35. herbivore this could mean a higher palatability of non- DIRZO, R., 1980. Experimental studies on slug-plant interac- natives compared to the native Cretan species. This is in tions. I. The acceptability of thirty plant species to the slug fact what we found, although the slightly higher mean Agriolimax caruanae.J. Ecol. 68, 981-998. palatability was statistically not significant. ELSTON, D. A., A. W. ILLIUS & I. J. GORDON, 1996. Assessment of preferences among a range of options using log ratio analysis. Ecology 77, 2538-2548.

GRIME, J. P., J. H. C. CORNELISSEN, K. THOMPSON & J. G. ACKNOWLEDGEMENTS HODGSON, 1996. Evidence of a causal connection between anti-herbivore defence and the decomposition rate of leaves. The work was carried out as part of the EU-funded Oikos 77, 489-494. 5th framework project EPIDEMIE (EVK2-CT-2000- GRIME, J. P., S. F. MACPHERSON-STEWART & R. S. DEARMAN, 00074). We gratefully acknowledge comments of Phil 1993. Palatability.In G. A. F. Hendry and J. P. Grime, edi- Lambdon, Phil Hulme and two anonymous referees on tors. Methods in Comparative Plant Ecology. Chapman & Hall, an earlier version. London, p. 117-121. HARBORNE, J. B., 1997. Plant secondary metabolism.In M.J. Crawley, editor.Plant Ecology. Blackwell, Oxford, p. 132-155. APPENDIX HARTLEY, S. E. & C. G. ONESJ , 1997. Plant chemistry and her- bivory, or why the world is green. In M.J. Crawley, editor. The table in the appendix gives data on PI, nativeness, Plant Ecology. Blackwell, Oxford, p. 284-324. woodiness, distribution and cover in the three vegetation HERMS, D. A. & W. J. MATTSON, 1992. The dilemma of plants: types for all 24 species. to grow or defend. Quart. Rev. Biol.67 , 283-335. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 171-178 ◆ C. F. DORMANN & R. KING

HEYWOOD, V. H., 1995. The Mediterranean flora in the context RADFORD, I. J. & R. D. COUSENS, 2000. Invasiveness and com- of world biodiversity. Ecol. Medit.20 , 11-18. parative life-history traits of exotic and indigenousSenecio HUENNEKE, L., 1988. SCOPE program in biological invasions: species in Australia. Oecologia125 , 531-542. a status report. Conserv. Biol.2 , 8-10. REJMÁNEK, M., 1996. A theory of seed plant invasiveness: the JONES, C. G. & S. E. HARTLEY, 1999. A protein competition first sketch. Biol. Conserv.78 , 171-181.

model of phenolic allocation. Oikos86 , 27-44. ROUX, E. R. & E. MIDDLEMISS, 1963. Studies in the autecology KEANE, R. M. & M. J. CRAWLEY, 2002. Exotic plant invasions of Australian acacias in South Africa. The occurrence and and the enemy release hypothesis. Trends Ecol. Evol. 17, distribution of Acacia cyanophylla and A. cyclops in the Cape 164-170. Province. S. Afric. J. Sci.59 , 286-294.

KERNEY, M. P., 1976. Atlas of the Non-Marine Mollusca of the SCHIERENBECK, K. A., R. N. MACK & R. A. SHARITZ, 1994. British Isles. Pemberley Books, Bucks, UK. Effects of herbivory on growth and biomass allocation in LARCHER, W., 1995. Physiological Plant Ecology, 3rd edition edi- native and introduced species of LoniceraEcology. 75, 1661- tion. Springer, Berlin. 1672.

LONSDALE, W. M., 1999. Global patterns of plant invasions and TURLAND, N. J., 1992. Floristic notes from Crete.Bot. J. Linn. the concept of invasibility. Ecology80 , 1522-1536. Soc. 108, 345-357. NOBLE, I. R., 1989. Attributes of invaders and the invading TURLAND, N. J., L. CHILTON & J. R. PRESS, 1993. Flora of the process: terrestrial and vascular plants. In J. A. Drake, 178 Cretan Area. Annotated Checklist and Atlas.Natural History H.A. Mooney, F. di Castri, R. H. Groves, F. J. Kruger, Museum, H.M.S.O., London. M. Rejmanek, and M. Williamson, editors.Biological Invasions: a Global Perspective. John Wiley & Sons, Chichester, VITOUSEK, P. M., 1988. Diversity and biological invasions of p. 301-313. oceanic islands. In E. O. Wilson, editor.Biodiversity . National Academy of Science, USA, Washington, p. 181-189. PINHEIRO, J. C. & D. M. BATES, 2000. Mixed-Effect Models in S and S-plus. Springer, New York. WILLIAMSON, M., 1999. Invasions.Ecography 22, 5-12. RACKHAM, O. & J. MOODY, 1996. The Making of the Cretan WILLIAMSON, M. H. & A. FITTER, 1996. The characters of suc- Landscape. Manchester University Press, Manchester. cessful invaders. Biol. Conserv.78 , 163-170.

ecologia mediterranea, tome 30, fascicule 2, 2004 Distribution and economic potential of the Sweet chestnut (Castanea sativa Mill.) in Europe Distribution et potentiel économique du châtaignier (Castanea sativa Mill.) en Europe

M. Conedera1, M.C. Manetti2, F. Giudici1 & E. Amorini2 1. WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Sottostazione Sud delle Alpi, CH 6504 Bellinzona, Switzerland. 2. C.R.A. Forest Research Institute – Viale S. Margherita 80, I-52100 Arezzo, Italy

Abstract Résumé No official and coherent data on the distribution of the European Il n’existe aucune donnée officielle et cohérente sur la distribution chestnut exist despite its wide range of distribution and the impor- du châtaignier en Europe, en dépit de sa vaste aire de répartition 179 tant economic role it has played in many countries. In 1997, in the et de l’important rôle économique que cette espèce a joué dans de framework of the COST action G4 “Multidisciplinary Chestnut nombreux pays. En 1997, dans le cadre de l’action COST G4 Research”, quantitative and qualitative data on chestnut forests were “Multidisciplinary Chestnut Research”, des données quantitatives et collected, mostly from the National Forest Inventories, in order to qualitatives ont été collectées au sujet des châtaigneraies européennes, provide as sound a picture as possible of this important European principalement à partir des inventaires forestiers nationaux. L’objectif resource. A total of 2.25 million hectares of forest dominated by ches- était de fournir un état des lieux aussi précis que possible pour cette tnut were recorded, with 1.78 million hectares (79.0 %) cultivated importance ressource économique. Un total de 2,25 millions d’hec- for wood and 0.43 million hectares (19.3 %) for fruit production. tares de boisements dominés par le châtaignier a été inventorié, avec The remaining 0.04 million hectares (1.7 %) were classified as irre- 1,78 millions d’hectares (79,0 %) cultivé pour la production de bois gular structures or without any indication. A further 0.31 million et 0,43 million d’hectares (19,3 %) pour la production fruitière. Les hectares are thought to be mixed forest with chestnut. 0,04 million d’hectares restants (1,7 %) ont été classés en structures Three types of chestnut countries can be distinguished: (i) coun- irrégulières ou n’ont pas pu être classifiés. Plus de 0,31 million hec- tries with a strong chestnut traditione.g. ( Italy, France, southern tares sont classés en tant que boisements mixtes à châtiagnier. Switzerland, Spain, Portugal and Greece), where the chestnut Trois types de pays peuvent être distingués du point de vue de la stands are cultivated with intensive and characteristic silvicultural castanéiculture : (i) les pays dotés d’une forte tradition castanéicole systems (coppices and orchards); (ii) countries with only a partially (ex. Italie, France, sud de la Suisse, Espagne, Portugal et Grèce), developed chestnut tradition due to the country’s particular geogra- où les châtaigneraies sont conduites en taillis ou futaies, grâce à des phy (e.g. England) or history (e.g. Croatia, Turkey, Georgia); (iii) sylvicultures intensives et caractéristiques ; (ii) les pays où la tradi- countries where the chestnut only sporadically occurs (e.g. Hungary, tion castanéicole n’est que partiellement développée en raison de Bulgaria, Belgium) or has been recently introduced (e.g. Slovakia, contraintes écologiques (ex.Angleterre) ou historique (ex.Croatie, Netherlands). Turquie, Géorgie) ; (iii) les pays où la castanéiculture n’est que A comparison of the present distribution of traditional silvicultural sporadique (ex. Hongrie, Bulgarie, Belgique) ou a été récemment systems and historical data on chestnut distribution supports the introduite (ex.Slovaquie, Pays-Bas). hypothesis that the large-scale chestnut forest plantations are of post- La confrontation de la distribution actuelle des pratiques tradition- Roman origin. Chestnut cultivation is now at a turning point as the nelles et des données historiques sur la répartition du châtaignier changed needs of society have changed as it has moved away from supporte l’hypothèse d’une origine post-romaine pour les peuplements a rural-based to an industrial and urban-oriented organization. de châtaignier présents sur de vastes étendus. La castanéiculure a été The evolution of the chestnut market in recent decades confirms profondément bouleversée par les changements socio-économiques liés the potential of this resource for both traditional products and new au passage d’une économie essentiellement rurale à une économique services and goods related to organic-food and environmentally de type industriel. Toutefois, l’évolution du marché durant ces friendly products. dernières décennies montre que le potentiel économique de cette ressource reste bien présent, à la fois pour des produits traditionnels mais aussi pour de nouveaux services et biens. Key-words Chestnut coppice, chestnut orchard, silvicultural systems, chestnut resources, Europe Mots-clés Châtaigneraies, systèmes sylvoculturaux, castanéiculture, Europe ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

ern and eastern part of Europe were not considered in INTRODUCTION the survey. The Sweet chestnut (Castanea sativa Mill.) is the only Starting in the 1960s, new data on chestnut distri- native species of the genus in Europe. The main chest- bution became available as national forest inventories nut refugia are though to be the Transcaucasian region, were carried out in several countries. But there were still north-western Anatolia, the hinterland of the Tyrrhenian problems with the classification of the different chestnut coast from Liguria to Lazio along the Apennine range, forest types as the surveying methods among the coun- the region around Lago di Monticchio (Monte Vulture) in tries were only partially comparable. The search for accu- southern Italy, the Cantabrian coast on the Iberian penin- rate data on chestnut resources in Europe has intensified sula, and probably also the Greek peninsula (Peloponnese in recent decades, since the chestnut tree was recognised and Thessaly) and north-eastern Italy (Colli Euganei, as a multipurpose species for landscape conservation in Monti Berici, Emilia-Romagna) (Krebs et al., 2004). marginal areas. Responding to this need, some authors Chestnut cultivation started early and has a long tra- have tried to synthesise the existing data, providing an dition in Europe, as it is a tree species that is suitable for overview of chestnut resources in the main European both timber and fruit production. The first written evi- countries (Bourgeois et al., 1991). dence of chestnut management is found in Theophrastus’ In 1997, within the framework of the COST action G4 “Multidisciplinary Chestnut Research” experts from “Inquiry into plants”, 3rd Century B.C. The Romans then 180 all European countries where chestnut is present, were introduced in most parts of Europe the idea of systemati- regrouped for the first time. During this action, quantita- cally cultivating and using the chestnut tree and, in certain tive and qualitative data on chestnut forests were collected cases, the tree itself (Conedera et al., 2004). In Medieval in order to provide as sound a picture as possible of this Times, people in several parts of Europe became greatly important European resource. In this paper we describe interested in cultivating chestnut, mostly for fruit produc- the project and discuss the collected data. tion. Chestnut cultivation was extended to the ecological limits of the species (Pitte, 1986). Despite the historical and economic importance of the European chestnut, no official and coherent data exist on the distribution of the species. The only attempt to survey chestnut resources in Europe was made in the fifties within MATERIAL AND METHODS the framework of the Chestnut International Commission. The International Commission consisted of a group of Data collection experts from different chestnut countries (Spain, Portugal, The experts (data contributors, see table 1) of the France, Switzerland, Italy, Yugoslavia, Turkey, Greece) who countries involved in the COST G4 action were asked to were charged with the analysis of the effects on chestnut provide data about the area covered by chestnut forests cultivation of the increasing abandonment of rural areas and the onset of pathologies such as Cryphonectria para- according to the typologies reported in table 2. The data sitica and Phythophtoraspp. Creating a chestnut distribu- were made available as a national report for each country tion map was listed as a priority (Groupe des Experts in which basic statistics were linked to other additional du Châtaignier 1951; Commission Internationale du information about silvicultural management, products Châtaignier 1953, 1955, 1958). and research activities. The information so obtained was then compiled together with local and international lite- One of the most interesting products of the rature on chestnut cultivation in Europe. International Commission was the chestnut distribu- tion map of Europe and the related quantitative data provided by the country reports presented during the Defining chestnut silvicultural typologies meetings of the Commission (Commission Internationale There are many different silvicultural systems applied du Châtaignier 1958). Unfortunately, the data are quite in chestnut stands in European countries, which makes it rough, due to different silvicultural approaches and clas- difficult to define a strict typology silvicultural practices. In sifications in chestnut stands throughout Europe (simple this work, we adopted a hierarchical classification (table 2), coppices, coppices with standards, high forests for timber first separating the chestnut forests (stands consisting of production, high forests for fruit production, orchards, more than 50 % of chestnut) from the mixed stands (ches- mixed stands). Moreover, several countries in the north- tnut less than 50 %). We then distinguished between stands

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆

Country Data contributor Data sources Albania Maxhun Dida and Caush Elezi Source not given National Forest Inventory 1997 Andorra Sebastià Semene Guiltart IEA Centre de Biodiversitat 2003 Austria Eva Wilhelm Source not given Azerbaijan Vagid Gadjiev Source not given Flemish Forest Inventory (1996-99) Belgium Hugues Lecomte and Klaartje van Loy Walloons: source not given Bosnia-Herzegovina Ahmet Lojo Source not given Bulgaria Svetla Doncheva Forest National Service Czech Republic Haltofová and Jankovsky (2004) Croatia Sanja Novak Agbaba Croatian Forest Service France Eric Sevrin National Forest Inventory (1999) Germany Volker André Bouffi er Seeman et al. (2001) Georgia Yuri Michailov Source not given Greece Gregor Chatziphilippidis and Stephanos Diamandis National Forest Inventory (1992), Diamandis (2002) Hungary Lazslo Radocz and Norbert Frank National inventories and others 181 National Forest Inventory (1985) Italy Maria Chiara Manetti National Statistics Institute (1993) Regional Forest Inventories, Ad hoc questionnaires Macedonia Sotirovski Kiril and Sumarski Fakultet Source not given Netherlands Anne Oosterbaan Estimated by the referent National Forest Inventory (1998) Portugal Afonso Martins National Statistics Institute (1987-1999) Romania Valentin Bolea and Danut Chira Source not given Russian Federation Michhail Pridnya, Gennadyi Solntsev and Yuri Michailov Source not given Serbia-Monte Negro Glisic (1975) Lesprojekt (General Directorate of State Forest) Slovakia Milan Bolvansky and Ferdinand Tokar Institute of Forest Ecology, Nitra Slovenia Anita Solar, Dusan Jurc Jurc (2002) Spain Juan Gaillardo Lancho and Santiago Lorenzo Pereira National Forest Inventory (1996) Switzerland Fulvio Giudici National Forest Inventory (1985) Turkey Necdet Guler, Ümit Serdar Agricultural statistics National Forest Inventory (1995-99) United Kingdom Nigel Braden and Karen Russell Forestry Commission Census (1979-82)

T able 1. Participating countries and data contributors.

Chestnut forests (chestnut area) Stands with more than 50 % chestnut Timber production Stands where wood production is prevalent Coppices Simple coppices. Coppices with standards « Natural » stands. Plantations High forests Stands converted into high forests Abandoned stands (coppices, orchards) with the structure of high forests

Fruit production Stands where fruit production is prevalent Orchards Stands with grafted trees (groves), including row plantations for fruit production High forests « Natural » stands. Plantations Irregular structure Stands without a edcodifi management Mixed forests with chestnut Stands with less than 50 % chestnut

Table 2. Definition of the chestnut forest types. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

with defined productive purposes (timber or fruit) and are dispersed in the other countries (table 3). For certain those without a codified management (irregular structure). countries, such as Albania, Austria, the Czech Republic The stands for timber production were subsequently divi- and Serbia-Montenegro, little information is available. ded into high forests and coppices and the stands for fruit We know roughly where chestnut forests may be found production into orchards and high forests. Coppices are (e.g. Glisic, 1975; Haltofová & Jankovsky, 2004), but no defined as pure chestnut forests regenerated from dormant further details about stand type, distribution and man- or adventitious buds of the stump for wood production agement are provided. For the countries not included (mostly poles and firewood). Orchards (or groves, as some in table 3, we assume that chestnut does not occur. A authors call them) are traditionally open stands composed comparison of the distribution map of current chestnut of grafted chestnut trees (selected varieties) for fruit pro- forests (fig. 1) with both the chestnut pollen map at the duction with intercropping of cereals (silvo-arable system, end of the Roman Period (ca. 570 AD, fig. 2a) and with usually wheat, oat or rye), hay or pasture (silvo-pastoral that at the end of the Middle Ages (ca. 1460 AD, fig. 2b), system). We classified as orchard also new plantations of shows that, especially in western Europe, the main chest- chestnut trees of selected varieties for fruit production nut areas coincide with the chestnut stands created since or row plantations of grafted chestnut trees. In contrast, the Middle Age, as already reported by several authors high forest was defined as chestnut stands that originated (Pitte, 1986; Fernandez de Ana Magán, 2002). directly from seedlings (i.e.without coppicing or grafting) The proportion of chestnut stands with respect to the 182 and that were used for timber or fruit production. total forest area is usually very low (< 1-3 %). Exceptions to this general picture are Georgia (16,1 %) and the two main West-European chestnut countries, Italy (7,7 %) Chestnut map and France (6,6 %). In some cases, the irregular distribu- A GIS-based chestnut map was constructed using the tion pattern of chestnut stands implies a contrast between the low percentages at the national level and the high original data from the International Chestnut Commission concentration of the species at the regional level. This is, (Commission Internationale du Châtaignier 1958). The experts were asked to update the map for their own coun- for instance, the case for Switzerland where the chestnut try or, for the countries with missing data in 1958, to pro- percentage is 1,2 % nationally and 12,9 % in the region vide a distribution map indicating the geographic location south of the Alps, the main chestnut-growing area (EAFV (polygons) of existing chestnut forest types. Where no 1988). In most countries, chestnut forests are cultivated forest type was indicated, the default classification of high along the mountain ranges, highlighting the orophilous forest was assumed. After scanning, the original chestnut (mountainous) character of the species. maps were georeferenced and the polygons digitalised by Unfortunately, it is not possible to analyze reliably hand with the best possible accuracy. the evolution of the total chestnut area for the countries included in the FAO survey of the fifties as the methods of data collection are not comparable. The FAO-survey considered only the managed and productive chestnut RESULTS AND DISCUSSION areas (Commission internationale du châtaignier, 1958), a category not considered in the present study. Chestnut area The reported chestnut area covers in total 2,53 million hectares in Europe, of which 2,25 million hectares are Chestnut forests for timber production chestnut forests, i.e. forests where chestnut is the domi- nant tree species and the remaining 0,31 million hectares In Europe, chestnut-growing area devoted to timber are mixed forests with chestnut (table 3). The distribu- production is 1,78 million hectares (table 3), correspond- tion area ranges from southern Europe (e.g. Crete) to ing to 79,0 % of the total chestnut-growing area. The fur- the North (southern England, Belgium) (fig. 1). The ther division of these stands into coppices and high forests European chestnut forests are concentrated in just a few is in some cases not clear, because of the problematic countries with a long tradition of chestnut cultivation classification of the coppices with standards. They tend (fig. 1). France and Italy together account for 79,3 % of to be classified as coppices or high forests, depending the whole chestnut forest area, with the other traditional on the different weight given to the reserve-trees. In this chestnut countries, Spain, Portugal and Switzerland, study, we accepted the classifications proposed by the accounting for a further 9,7 %. The remaining 11,0 % data contributors.

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆

183

Fig. 1. Present distribution of the chestnut in Europe.

The traditional silvicultural method of timber pro- that were abandoned at the beginning of the last century duction, the “coppice system”, is still widely applied in and then coppiced because of the high incidence of the countries where chestnut cultivation was widespread in chestnut blight and of the demand for chestnut wood for the past to satisfy the needs of rural populations located tannin, mining and – especially in Spain – for barrels in marginal or mountainous areas and where the chestnut (Pitte, 1986; Conedera et al., 1997; Fernandez de Ana found suitable climate and soil conditions in Italy, France, Magán, 2002). In these areas, there are now a number Spain, Greece and Southern Switzerland (fig. 3 and 4; of atypical coppice stands, derived from orchards and table 3). characterized by very low stool density and poor quality There are several reasons for the large number of shoots. According to Taniet al. (2003), two or three gen- coppice stands. They used to be popular because small erations of coppicing are needed in these cases, to regain and medium traditional chestnut products e.g.( poles) a satisfactory stool density in the stands. were important in the national and local economies. In Since the late fifties, the silvicultural rules applied to addition, chestnut stools have a high resprouting capac- coppice stands required a rotation period from 5 to 12 ity, and the shoots grows remarkably quickly (Manetti years (simple coppicing), or 25-30 years in cases with 2-3 et al., 2001). Moreover, many coppices in France, Italy, spacings and thinnings, depending on the desired prod- Spain and Switzerland were originally ancient orchards, ucts and the type of ownership. Changes in the socio- ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI remarks ed management ed ed management ed confusion between high forests and orchards may high forests and orchards may confusion between exist sporadic presence of chestnut in forest stands missing value in mixed forests chestnut covers about 30% of the forests chestnut covers in mixed basal area. coppice and high forest distribution between estimated. chestnut present as single tree or tree cohorts in more available data No quantitative than 300 localities. coppice includes coppice with standards data source uncertaindata and solitary including avenue only total area available, stands are assumed to be prevalent coppice trees; irregular structure intended as forest without a codifi irregular structure intended as forest without a codifi chestnut presents in few spots. No quantitative data data No quantitative chestnut presents in few spots. available no detailed information on the special distribution of the different silvicultural systems confusion between high forests and orchards may high forests and orchards may confusion between or dispersed single orchard trees are not exist; included forests intended as chestnut presence less then mixed 25% of the basal area 45 700 high forests mostly for fruit production 480 650 250 200 1800 4450 4585 1600 7000 6800 a 50%) MIXED FORESTS (chestnut < 0.30.7 28000 10871 < 2 ha are not included woods isolated 0.9 0.0 0.1 0.2 0.1 0.1 0.8 22362 6.7 0.0 0.9 0.1 7.7 0.6 0.0 1.50.0 0.0 21400 coppice are included in the high forest area 0.1 2.7 202308 1.0 2.3 16.1 %h area chestnut forests vs 184 total forest % 0 0.0 50 0.0 8600 0.4 1500 0.1 1050 0.0 2960 0.1 3057 0.1 4400 0.2 2000 0.1 5058 0.2 2990 0.1 1505 0.1 2889218788 1.3 0.8 15000 0.7 48000 2.1 33651 1.5 53509 2.4 40000 1.8 30185 1.3 27100 1.2 ha 765837 34.0 137627 6.1 1020500 45.3 CHESTNUT AREA 95 5058 ha Irregular structure 0 92 900 100 185 3400 ha 19609 37679 100000 235620 32347 TOTAL 720 720 140 600 600 8600 8600 1500 1500 25278 25278 ha High forests 92 900 100 185 CHESTNUT FORESTS (chestnut > 50%) ha Orchards 0 50 3614 3057 4400 ha 33051 TOTAL 2890 2890 48000 48000 33900 3390040000 19609 40000 30000 30000 ha High forests 50 16 1302 1318 65.9 13.2 79.0 17.7 1.6 19.3 1.7 100.0 TIMBER PRODUCTION PRODUCTION FRUIT ha Coppices 39 2 1) km Total forest area 45 1) 2 2740 991 8273 9402 83593025 1094 620 750 300 1050 7728 2632 5100 22735592 3057 1783 14580 420 15000 6831 298 9234 1840 300 800 1100 2543 906 33929150 375 3666 4808 2177 2012 1107 3955 1199 19000 4700 23700 3400 76963 10225 3614 11055 3690 2000 100 2100 55010 15341 862500 58000 920500 100000 3492712890 1074029406 3599 4400 10003 33051 482751 15119 497870 235620 23034 6448 10200 2887 49945 14370 49909 50039 99948 37679 km Total Total area 1688851 851392 country country urkey TOTAL% of chestnut area 2099228 961891 1483891 296445 1780336 397585 36698 434283 37640 2252259 100.0 313501 United Kingdom 24160 2794 7913 10875 18788 Albania Andorra Austria Azerbaijan Belgium Bulgaria Czech Republic Bosnia- Herzegovina Croatia France Georgia Hungary Germany Greece Italy Macedonia Romania Netherlands Portugal Russian Federation Serbia-Monte Negro Slovakia Slovenia Spain Switzerland T

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆

The thinning type varies from selective to low thinning, economical structure of the rural areas and the crisis in probably according to the silvicultural tradition of the the market for poles meant that different silvicultural country concerned (table 4). treatments were needed to satisfy the new demand for In summary, there appears to be variety in the silvi- larger size and higher quality products. cultural treatments (rotation period, type, frequency and As a results of these developments, the silvicultural intensity of thinnings) applied to chestnut coppice and systems for chestnut timber production applied are now high forest stands in Europe. Above all, it seems silvicul- very diverse, both within and among chestnut-growing ture interventions are often applied without an exhaustive countries. In certain cases, the rotation period has been analysis of their ecological impact on the forest ecosys- extended without any planned active silvicultural inter- tem, and without a preventive analysis of the relevant vention and no well-defined long- or medium-term objec- ecological parameters (which include site index, climatic tives. In some countries such as Italy, Spain and the United characteristics, and soil type) or of the main structural Kingdom, coppices have been converted into high forests parameters (e.g. silvicultural system, stand density, domi- or, in extreme cases, have just not been cut and have thus nant height, degree of mixture). developed into high forest-like stands. Nevertheless, in some European countries, such as France, Greece, Italy, Portugal, Spain, Southern Switzerland and the United Chestnut forests for fruit production Kingdom, private chestnut coppices are still cultivated 185 in a short rotation period (10-20 years) without thin- The chestnut-growing area devoted to fruit produc- nings (rarely 1, early and from below) to produce poles tion covers 0,43 million hectares (table 3), corresponding and small products, mainly in the private ownership. The to 19,3 % of the total chestnut-growing area. According to application of long-rotation periods (30-60 years) and our survey, Italy and France are nowadays the countries selective thinnings, however, are reported for Croatia, with the largest orchard areas (together they account for Bulgaria and Germany. Finally, there have been recent 84,5 % of the total reported orchard area). Thus, simi- experiments in France, Italy and Spain in the face of the lar to the coppice stands, orchards grown according to growing demand for chestnut wood products. Here the traditional silvicultural methods for fruit production are management policy has been to have rotation periods of mostly found in countries with a long tradition of chest- 25-35 years and 1-2 thinnings from below), in order to nut cultivation (fig. 5; table 3). During the Middle Ages, produce timber of higher quality, especially with a low the chestnut was an essential source of food for many incidence of ring shake (table 4). mountain regions of those countries and this resulted in High forest stands, representing only 16,7 % (= ap- a wide range of products and of cultivated varieties with prox. 296 500 ha) of the chestnut-growing area devoted different ripening periods (early, mid-season, late), types to timber production, are prevalent in those countries that of use (fresh consumption, long-term storage, drying, have recently introduced chestnut cultivation (Slovakia, flour, animal feed) and ranges of distribution (higher Hungary), and in those where there is no specific chest- altitudes, lower slopes, ubiquitous, etc.). This gave nut silviculture (Romania, Russia), or where the adopted rise to a very complex and highly structured chestnut silvicultural practices early modified the forest structures, culture with a considerable number of different chestnut giving them the appearance of high forest-like stands varieties cultivated for different purposes (Conederaet (Portugal, Romania). al., 1993). In mixed forests, the silvicultural treatment is generally The few regions where commercial transport routes uniform and the chestnut is managed in the same way as already existed during the Middle Ages e.g( . Piedmont other species. In such stands, management generally fol- or Tuscany), where the only places where chestnut lows a rotation period of 40-60 years, or, more rarely, of plantations with just one or few high-quality chestnut or 80-100 years or more (Slovakia, Bulgaria and Romania), marron-cultivars were started in this period. The fruits and thinnings are carried out every 5-10 or 10-20 years. were then sold on the regional or even international

Table 3. Chestnut forest area according to defined forest types in Europe..

1 FAO, 2003: State of the World's Forests (SOFO), Rome, XIV, 151 p. Land area refers to the total area, excluding areas under inland water bodies. The source of these data is FAO (2001); they may differ slightly from those in the State of the World's Forests 2001, which used a different source. The forest cover fi gure for each country has been calibrated to the country's land area. ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

186

Fig. 2a. Chestnut pollen map 570 AD (source Conederaet al., 2004).

markets (Pitte, 1986). The marron varieties, then defined as above ground level (Bourgeois et al., 2004). This complex elliptic-shaped fruits of medium to large size, with marked historical background makes it impossible to reliably esti- dark strips on the tegument, which are light to peel (no mate the number of chestnut cultivars or ecotypes exist- intrusion of the epispermatic pellicle in the cotyledons) ing in Europe, even if the inventories so far performed at and sweet in taste (Bassi, 1993), have traditionally been the national level suggest that there are thousands more cultivated only in Italy and a few areas in France. In all varieties (Pitte, 1986). other countries marron-cultivars do not exist or are of In chestnut-growing areas cultivated as orchards, the recent import (e.g. southern Switzerland, Conedera et quantity of chestnut produced in the main chestnut- al., 1997). In France, the definition of marrons has been growing countries has dramatically decreased since the recently revised in order to better fit the market and com- beginnig of the 20ies Century although it begin to pick mercial needs. According to Bergougnouxet al. (1978), up again towards the end of the heigties (fig. 6). This marron varieties should not display more than 12 % fruit development is mainly due to the progressive depopula- with end-to-end epispermatic intrusions. tion of the countryside, the abandonment of chestnut as a staple food, the introduction and spread of ink disease In some regions of the Iberian Peninsula (northern and chestnut blight, and the increased demand for wood Portugal and Galicia), double-purpose varieties (fruit and for tannin extracts (Pitte, 1986; Bounous & De Guarda, timber production) are quite common. Here the chestnut 2002). Chestnut fruit cultivation has survived or quickly trees are topped above the grafting point, usually 2 meters

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆ recovered best where the high-quality marron and chest- ties have been cultivated in several countries (mostly in nut cultivars are cultivated (Italy and, to a lesser extent, France, Spain and Italy). France) or where the large-size chestnut varieties are High forests for fruit production are rare (covering grown (Spain, Portugal, Turkey and France) (Alvisi, approx. 36 700 ha in Europe, which corresponds to 8,5 % 1994). In the Iberian Peninsula, intercropping with cereal of the fruit production area). Most of them are located is becoming rare, but the practice of soil tillage is used to in Turkey. According to Soyluet al. (2002), the grafting increase nut production (Berrocal del Brioet al., 1998; of chestnut trees is not very common in the Black Sea Portela et al., 1999). region. In some unclear cases, such as the attribution Since 1990s, people have become more aware of the to the “soto”-type (= orchard) of some fruit-producing value of chestnut orchards as a multifunctional landscape stands in Spain, the corresponding area was classified as element. In many countries they have begun to revitalize “orchard”. chestnut orchards as they see them as having aesthetic and ecological value, acting as tourist attractions, and serv- ing as fire-breaks (Bounous et al., 1992, Conedera et al., Chestnut products 1997). Besides the revitalisation of traditional orchards The increasing demand for natural and environmentally in marginal chestnut-growing areas, new plantations (or friendly products in Europe has led to more interest in even re-grafted old orchards) with high-quality varieties the chestnut. Moreover, some recent technological 187 (marrons and similar) or large-size Euro-Japanese varie- improvements (laminated veneer boards, finger-jointed

Fig. 2b. Chestnut pollen map 1460 AD (source Conederaet al., 2004). ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

Timber production Coppices High Forests rotation (years) thinnings (number) type of thinning rotation (years) thinnings (number) type of thinnings Belgium No information Generally in mixed stands Bosnia-Herzegovina Clear cutting when blighted No high forests Bulgaria No information Croatia 40-60 yes selective Generally in mixed stands France 25-35 1 (9-12 yrs) low 40-60 2-3 (every 10-15 yrs) selective Germany 20-30 No information 60-80 No information Greece 20-25 2 (7, 14 yrs) low No high forests Hungary No coppice stands No information Italy 12-18 / 25-30 no / 1-2 low 50-60 2-3 (every 10-15 yrs) low Netherlands Generally in mixed forests No high forests Portugal 15 1 (at 2 yrs) low 40-45 5 (every 8-10 yrs) low Romania No coppice stands 120 every 5-10 yrs low 188 Russian Federation No coppice stands Generally in mixed forests Slovakia No coppice stands 100-120 every 10-15 yrs selective Slovenia No information Spain 5-8 // 18-25 no // 2 (5, 12) low 40-60 2-3 (every 10-15 yrs) selective Switzerland 12-18 None 30-60 ?? selective Turkey No information No high forests United Kingdom 12-20 None Generally in mixed forests

Table 4. Main characteristics of the silvicultural management applied in the different countries for chestnut timber. production

exemplary model of multifunctional forestry (figure 7), beams and boards, thick sliced veneer, better use of playing an important social and economic role in rural industrial wood through joint production of tannin and areas. panels, fruit conservation and processing techniques) The recent development of the chestnut market has have also positive driving forces influencing the chestnut not been homogeneous. It is frequently affected by agri- market (Pettenella, 2001). As a consequence, traditional cultural, economic, and social and cultural local factors chestnut products have now more opportunities on the (Hennion & Vernin, 2000). Pettenella (2001) provides market (poles for land consolidation work or playgrounds, examples of niche chestnut markets, but the evidence of logs for flooring, chestnut flour for pasta production, these is largely anecdotal and there are no figures avail- certification of local cultivars, etc.) and new products able. For example, chestnut sawnwood for solid wood (chestnut parquet, chestnut-laminated veneer boards, furniture production is in great demand in Tuscany chestnut pasta, chestnut beer, etc.) have been launched. (Italy), logs for floorings are highly desiderable in France, Some of these new products and new applications, such poles for land consolidation, torrent and avalanche con- as finger-jointed beams, and shingles from the wood, trol works are used in Switzerland, the production of and pasta, biscuits, beer from the fruit are particularly chestnut-laminated beams and panels is increasing in interesting because it is possible to produce them from north-east Italy, chestnut flour has an expanding market small-sized chestnut timber or fruit. In addition, the in Bosnia, and so on. aesthetic, cultural and ecological value of managed A precise quantification of the total amount of chestnut ecosystems is now much more recognized. chestnut timber and fruit production is difficult because Restoring chestnut growing areas is also valued for its of both missing information in the official statistics and role in preserving landscape and a country’s traditional the existence of an unregistered parallel market (direct heritage (Conedera et al., 1997, Bounouset al., 2001). sales, self-consumption, fruits left on the ground by In conclusion, chestnut cultivation today provides an

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆

189

Fig. 3. Present distribution of chestnut coppices in Europe.

Fruit Timber Country chestnuts (tons) Sawnwood3 )(m Poles (m3) Tannin and industry 3(m) Croatia 2,000 1,000 20,000 France 13,000 115,000 310,000 500,000 Greece 12,000 Germany 1,000 5,000 Italy 52,000 54,000 300,000 150,000 Portugal 33,000 Slovenia 16,000 Spain 10,000 8,000 12,000 Turkey 60,000 140,000 Switzerland 10,000 20,000 Other European countries 154,000 Europe 351,000

Tab. 5. Chestnut products in Europe (reference year, 2000). Source: FAO (FAOSTAT Agriculture Data - Agricultural Production - Crops Primary; http://apps.fao.org/) and Data contributors of the Cost Action G4 (see Table 1). ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

Fig. 4. Percentage distribution of the two different timber- producing silvicultural systems coppices (grey) and high forests (black) in the surveyed countries.

190

Fig. 5. Present distribution of chestnut orchards in Europe.

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆ livestock, etc.). For fruit, the official statistics provided by dition due to their particular geography e.g.( England) the FAO indicate that around 350 000 tons of chestnuts or history (e.g. Slovenia, Croatia, Turkey, Georgia); (iii) are produced a year all over Europe (table 5). No official countries where the chestnut only occurs sporadically statistics exist for chestnut timber production, and only (e.g. Hungary, Bulgaria, Belgium) or has been recently a few countries were able to provide data within the introduced (e.g. Slovakia, Netherlands). framework of the G4 Cost Action (table 5). Although Despite this historical background, chestnut cultivation incomplete, the data clearly show the poor amount of is now at a turning point and is being confronted chestnut timber products of high value (i.e. sawnwood). with changing needs of a society that has moved from This is probably due to the general lack of tradition in being rural to becoming industrial and urban-oriented. applying silvicultural treatments to improve the wood The development of the chestnut market in recent quality of the wood in the chestnut coppices. decades confirms the potential of this resource for both traditional products and new services and goods related to organic food and environmentally friendly products. This is particularly important for the chestnut as it is widespread in the territory particularly cut off from the CONCLUSIONS main industrial developments. Silvicultural management trends are already reacting to these developments. The Chestnut cultivation has a long tradition and deep roots 191 cultivation of high-value chestnut products (fruit or in many European countries. The European countries timber) is being intensified in the best chestnut-growing with chestnut histories and tradition, can be divided into areas, new plantations are being created in potentially three main categories: (i) countries with a strong chestnut good sites for the chestnut, and traditional old orchards tradition (e.g. Italy, France, southern Switzerland, Spain, are being restored as part of a multipurpose landscape. Portugal and Greece), where chestnut stands have been At the same time, chestnut cultivation is being abandoned cultivated since centuries with intensive and character- in the very marginal areas, where the old chestnut stands istic silvicultural methods (coppice and orchards); (ii) will evolve into mixed stands. countries with a only partially developed chestnut tra-

Fig. 6. Evolution of chestnut fruit production (tons) in different European countries since 1960. Source: FAO (FAOSTAT Agriculture Data - Agricultural Production - Crops Primary;http://apps.fao.org/ ) and Commission Inter nationale du châtaignier (1958).

ecologia mediterranea, tome 30, fascicule 2, 2004, p. 179-193 ◆ M. CONEDERA, M. C. MANETTI, F. GIUDICI & E. AMORINI

Fig. 7. Products and services provided by chestnut forests classified according to the management system (modified from Pettenella 2001).

192 Given this dynamic situation, new marketing BERROCAL DEL BRIO M., GALLARDO LANCHO J.F. & CARDEÑOSO instruments will have to be developed, such as the HERRERO J.M., 1998. El castaño. Ediciones Mundi-Prensa, certifying and registering the place of origin and the Madrid, 288 p. system of cultivation (Pettenella, 2001). More research BOUNOUS G., BOUCHET M. & GOURDON L., 1992. Ricostituzione is also needed to develop sound silvicultural techniques del castagneto a frutto tradizionale: interventi in Piemonte e to solve problems related to the correct management of nel Sud della Francia. L’Informatore Agrario, 9: 155-160. chestnut stands to best take into account not only pro- BOUNOUS G., BAGNARESI U., BELLINI E. & BECCARO G., 2001. ductive aspects, but also the historical value of the for- Aspetti paesaggistici e culturali del castagno: problemati- ests, the establishment of multifunctional stands, and the che di tutela e valorizzazione. In: Bellini E. (ed.), Atti del improvement of the ecological and environmental value “Convegno Nazionale Castagno 2001”, Marradi (Firenze) 25-27 ottobre 2001. 365-372. of the landscape. BOUNOUS G. & DE GUARDA A., 2002. Origine e cenni storici. In: Bounous G. (ed.) Il castagno. Coltura, ambiente ed utilizzazioni in Italia e nel mondo. Bologna, Edagricole. 3-17. Acknowledgements BOURGEOIS C., LOPEZ J. & GAROLERA E., 1991. Le châtaignier Our heartfelt thanks go to the data contributors for en Europe. Forêt-Entreprise 76, 25-42. providing us with the national information, to our collea- BOURGEOIS C., SEVRIN E. & LEMAIRE J., 2004. Le châtaignier: un gues François Romane and Patrick Fonti for the critical arbre, un bois. 2nd revised edition, Institut pour le développe- reading of the manuscript, to Florian Boller, Damiano ment forestier, Paris, 347 p. Torriani and Daniela Furrer for the digitalisation of the COMMISSION INTERNATIONALE DU CHÂTAIGNIER, 1953. Rapport chestnut maps, and to Silvia Dingwall for the English de la 2e session. FAO 54/7/4069, Rome, 62 p. revision of the text. — 1955. Rapport de la 3e session. FAO CH/19, Rome, 62 p. — 1958. Rapport de la 4e session. FAO CH/26, Rome, 57 p. CONEDERA M., MÜLLER-STARCK G. & FINESCHI S., 1993. Genetic characterization of cultivated varieties of European References Chestnut (Castanea sativaMill.) in Southern Switzerland. (I) Inventory of chestnut varieties: history and perspectives. ALVISI F., 1994. Aspetti economici e commerciali della casta- In: Comunità Montana Monti Martani e Serano of Spoleto; nicoltura italiana. Rivista di frutticoltura e di ortofloricoltura, Istituto di Coltivazioni Arboree University of Perugia (eds.) 56, 2: 41-47. Proceedings of the International Congress on Chestnut BASSI D., 1993. Castagno da frutto: valorizziamo la qualità. Spoleto, Italy, October 20-23, 1993: 299-302. Rivista di frutticoltura, 55, 12: 39-41. CONEDERA M., JERMINI M. & SASSELLA A., 1997. Nouvelles BERGOUGNOUX F. , VERLHAC A., BREISCH H. & CHAPA J. 1998. Le perspectives pour la culture du châtaignier au sud des Alpes. châtaignier. Production et culture. Invuflec Malemort, 192 p. Rev. suisse vitic. arboric. hortic., 29, 6: 337-344.

ecologia mediterranea, tome 30, fascicule 2, 2004 DISTRIBUTION AND ECONOMIC POTENTIAL OF THE SWEET CHESTNUT (CASTANEA SATIVA MILL.) IN EUROPE ◆

CONEDERA M., KREBS P. , TINNER W. , PRADELLA M. & KREBS P. , CONEDERA M., PRADELLA M., TORRIANI D., FELBER M. TORRIANI D., 2004. The cultivation ofCastanea sativa (Mill.) & TINNER W., 2004. Quaternary refugia of the sweet chestnut in Europe: from its origin to its diffusion on a continental (Castanea sativa Mill.): an extended palynological approach. scale. Vegetation History and Archaeobotany, 13: 161-179. Vegetation History and Archaeobotany, 13, 145-160.

DIAMANDIS S., 2002. Grecia.In : Bounous G. (ed.)Il castagno. MANETTI M.C., AMORINI E., BECAGLI C., CONEDERA M. & Coltura, ambiente ed utilizzazioni in Italia e nel mondo. GIUDICI F., 2001. Productive potential of chestnut (Castanea Bologna, Edagricole. 253-260. sativa Mill.) stands in Europe. For. Snow Landsc. Res. 76, 3: EAFV (EIDGENÖSSISCHE FORSCHUNGSANSTALT FÜR DAS 471-476. FORSTWESEN), 1988. Schweizerische Landesforstinventar. PETTENELLA D., 2001. Marketing perspectives and instruments Ergebnisse der Erstaufnahme 1982-1986. EAFV Bericht 305, for chestnut products and services.For. Snow Landsc. Res. 1-375. 76, 3: 511-517. FERNANDEZ DE ANA MAGÁN F.J., 2002. Spagna.In: Bounous G. PITTE J.R., 1986. Terres de castanide. Hommes et paysages du châ- (ed.) Il castagno. Coltura, ambiente ed utilizzazioni in Italia e taignier de l’Antiquité à nos jours.Librairie Arthème Fayard, nel mondo. Bologna, Edagricole. 265-273. Paris, 479 p. GLISIC M., 1975. Le châtaignier Castanea( sativa Mill.) en Serbie PORTELA E., ARAHNA J., MARTINS A. & PIRES A.L., 1999. et sa variabilité biologique et écologique. PhD Thesis, Institut Soil factors, farmer’s practices and chestnut ink disease: de sylviculture et d’Insdustrie du bois, Belgrade, 211 p. (in some interactions. In: Proceedings of the Second International Serbian). Symposium on Chestnut (Ed. Salesses G.),Acta Horticulturae 193 494, 433-441. GROUPE DES EXPERTS DU CHÂTAIGNIER, 1951. Rapport de la première session. FAO 53/2/1423, Rome, 50 p. SEEMANN P. , BOUFFIER V. , KEHR R., WULF A., SCHRÖDER HALTOFOVÁ P. & JANKOVSKY L., 2004. Distribution and healt T. & UNGER J., 2001. Die Esskastanie Castanea( sativa condition of sweet chestnut (Castanea sativa Mill.) in the Czech Mill.) in Deutschland und ihre Gefährdung durch den Republic. In: IIIe International Symposium on Chestnut, Chaves, Kastanienrindenkrebs Cryphonectria( parasitica [Murr.] 20-23 October 2004, Abstracts, 60. Barr.). Nachrichtenbl. Deut. Pflanzenschutzd., 53: 49-60.

HENNION B. & VERNIN X., 2000. Châtaigne. Forces et faiblesses SOYLU A., SERDAR Ü., ERTÜRK Ü., 2002. Chestnut growing de la filière. Infos Ctifl, 166, 14-17. in Turkey and researches on its problems. FAO-CIHEAM Nucis-Newsletter,11: 34-38. JURC D., 2002. An overview of the history of the chestnut blight epidemic in Slovenia. Research reports forestry and wood science TANI A., MALTONI A. & MARIOTTI B., 2003. La produzione and technology, 68: 33-59. legnosa di castagno in Italia. Situazione attuale e prospettive. Sherwood, 92, 5-9.

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