Mediterranean pines and their history

The assembly of Mediterranean pines in the sense ofMirov is inhomogeneous in respect to morphological, geographical and evolutionary affinities. Considering new or neglected characters (vegetative and particularly reproductive, cone scales, apophyses, mucros, seeds: Figs. 1–3) in extant populations and fossils, three groups are recognized. The group of coast and island pines extends from the Canary islands to the Himalaya region and is closely related to Caribbean and C. American taxa. This complex evidently has originated from haploxyl ancestors of sect.Parrya during the Mesozoic (Upper Jurassic/Lower Cretaceous) in the NW. Tethys area (Fig. 13).P. rzedowskii can be regarded as an extant survivor of this first phase of differentiation. The extremely variableP. canariensis (together withP. roxburghii in sect.Sula) marks a transitional phase towards the more advanced diploxyl species of sect.Pinea (withP. pinea, P. halepensis &P. brutia, and subsect.Oocarpae) and sect.Pinaster (withP. pinaster, etc.) (Figs. 4–12).—The second group consists of diploxyl mountain pines from the areas surrounding the Mediterranean. They are classified as members of the Eurasiatic sect.Pinus subsect.Sylvestres, have differentiated along the northern Parathetys area, and exhibit close links with E. Asiatic taxa. The third group includes the haploxyl mountain pinesP. cembra andP. peuce which can be regarded as western outposts of the circumpacific centred sect.Strobus with a pre-Tertiary origin.—As an appendix, an improved classification scheme is presented for the pine groups discussed.     

Paleobotanical studies inFagaceae of the European Tertiary

A systematic reassessment of megafossil records ofFagaceae in Central Europe has been undertaken on the basis of leaf cuticular characters. The oldest representatives date back to the Eocene:Quercus subhercynica spec. nova,Dryophyllum furcinerve (Rossm.)Schmalh.,Trigonobalanopsis rhamnoides (Rossm.) gen. & comb. nov. In the Oligocene other members of extant genera appear:Quercus rhenana (Weyl. & Kilpp.)Knobloch & Kvaek,Fagus attenuata Goepp.,Lithocarpus saxonicus spec. nova. In the Neogene these ancient taxa (except inFagus lineage), are gradually replaced by deciduous species ofQuercus andCastanea. Trigonobalanus andCastanopsis are recorded by fruits (or wood) only.     

Paleobotanical evidence on the early radiation of nonmagnoliid dicotyledons

Paleobotanical studies indicate that several isolated and systematically depauperate groups of extant woody dicotyledons originated in the Mid Cretaceous. TheChloranthaceae had probably differentiated into insect-pollinated (Chloranthus andSarcandra) and wind-pollinated (Ascarina andHedyosmum) forms by the end of the Albian, and leaves referable to theTrochodendrales are known from the Albian and Cenomanian. In the latest Cretaceous and Early Tertiary, extinct representatives of theTrochodendrales includedNordenskioldia and theJoffrea-Nyssidium complex. ThePlatanaceae also differentiated before the end of the Albian and initially had insect-pollinated, unisexual flowers with five carpels or stamens. Some of these features persisted in the platanoid lineage until the Early Tertiary, and during the Paleocene and Eocene thePlatanaceae included forms with elliptical, palmate and pinnate foliage. The history of thePlatanaceae suggests that several features of the reproductive morphology of extant taxa may have arisen in association with a trend toward wind pollination. In the Mid Cretaceous, platanoid foliage partially intergrades with pinnateSapindopsis and pedateDebeya-Dewalquea leaves suggesting a close relationship betweenPlatanaceae andRosidae andFagaceae respectively. TheChloranthaceae, Trochodendrales, andPlatanaceae all occupy a somewhat intermediate position between theMagnoliidae andHamamelidae and are of considerable interest with respect to their role in the initial radiation of nonmagnoliid (higher) dicotyledons.     

Adaptive photosynthetic strategies of the Mediterranean maquis species according to their origin

In consideration of their origin the adaptive strategies of the evergreen species of the Mediterranean maquis were analysed. Rosmarinus officinalis L., Erica arborea L., and Erica multiflora L. had the lowest net photosynthetic rate (P_N) in the favourable period [7.8±0.6 mol(CO₂) m^–2s^–1, mean value], the highest P_N decrease (on an average 86 % of the maximum) but the highest recovery capacity (>70 % of the maximum) at the first rainfall in September. Cistus incanus L. and Arbutus unedo L. had the highest P_N during the favourable period [15.5±5.2 mol(CO₂) m^–2s^–1, mean value], 79 % decrease during drought, and a lower recovery capacity (on an average 54 %). Quercus ilex L., Phillyrea latifolia L., and Pistacia lentiscus L. had an intermediate P_N in the favourable period [9.2±1.3 mol(CO2) m^–2s^–1, mean value], a lower reduction during drought (on an average 63 %), and a range from 62 % (Q. ilex and P. latifolia) to 39 % (P. lentiscus) of recovery capacity. The Mediterranean species had higher decrease in P_N and stomatal conductance during drought and a higher recovery capacity than the pre-Mediterranean species. Among the pre-Mediterranean species, P. latifoliahad the best adaptation to long drought periods also by its higher leaf mass per area (LMA) which lowered leaf temperature thus decreasing transpiration rate during drought. Moreover, its leaf longevity determined a more stable leaf biomass during the year. Among the Mediteranean species, R. officinalis was the best adapted species to short drought periods by its ability to rapidly recover. Nevertheless, R. officinalis had the lowest tolerance to high temperatures by its P_N dropping below half its maximum value when leaf temperature was over 33.6°C. R. officinalismay be used as a bioindicator species of global change.This revised version was published online in March 2005 with corrections to the page numbers.     

Life history response of female Mediterranean fruit flies, Ceratitis capitata, to periods of host deprivation

Female medflies were subjected to four different patterns of host deprivation at each of three levels for a 24-day period. Treatments ranged from host absence 8 days post-eclosion to host absence 2 out of 3 days. Survival was recorded daily and egg production was recorded on the days in which hosts were present.The direct effect of host deprivation is to deny females the opportunity to oviposit. This disrupts their reproductive cycle and reduces their overall reproductive effort. Reduced reproductive effort at young ages increases survival (up to 2-fold) and daily reproduction (up to 8-fold) at older ages. Therefore, the long term effect of host deprivation is to postpone senescence.The implications of these findings regarding medfly sensescence are discussed in relation to: (i) reduction in population extinction rates during periods of host scarcity and (ii) egging strategies in medfly mass-rearing.

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Résumé Les femelles de C. capitata ont été privées d'hôtes suivant 4 modalités pendant 3 durées (33, 50 et 67% de leur vie) par période de 24 heures. Les modalités se répartissaient de la privation pendant 8 jours après l'éclosion jusqu'à 1 jour sur 3. La survie a été notée chaque jour et la ponte pour tous les jours où il y avait des hôtes.L'effect direct de l'absence d'hôte est d'empêcher la femelle de pondre. Ceci interrompt leur cycle de ponte et réduit leur activité reproductrice totale. Un effort reproductif réduit des femelles jeunes augmente la survie (jusqu'à 2 fois) et la ponte quotidienne (jusqu'à 8 fois) chez les femelles plus âgées. Ainsi, l'effet à long terme de la privation d'hôtes est d'ajourner la sénescence.Les implications de ces observations sur la sénescence de C. capitata sont discutées quant à: (1) la réduction des taux d'extinction des populations pendant les périodes de rareté d'hôtes; et: (2) les stratégies d'obtention de pontes dan les élevages de masse de C. capitata.

     

Effects of UV-B radiation and additional irrigation on the Mediterranean evergreen sclerophyll Ceratonia siliqua L. under field conditions

Seedlings of Ceratonia siliqua L. were grown for 1 year in the field under ambient or ambient plus supplemental UV-B radiation (corresponding to 15% ozone depletion over Patras) and received two levels of additional irrigation during the summer dry period. The experiment was started during February 1998 and two major samplings were performed, the first at the end of the dry period (September 1998) and the second at the end of the experiment (January 1999). Plants receiving additional irrigation showed significantly higher leaf number, plant height and chlorophyll content at the end of the summer, but these differences were abolished at the final harvest. Plants growing under enhanced UV-B radiation had significantly fewer leaves and less nitrogen content at the end of the dry period, but these effects were also abolished at the final harvest, during which significant UV-B induced increases in stem dry mass were observed. None of the other measured parameters (mean leaf area, leaf dry mass, leaf thickness, UV-B absorbing compounds, phenolics, tannins and photochemical efficiency of PSII) were affected by either treatment. Combined UV-B / water effects were not significant. We may conclude that although some minor responses to enhanced UV-B radiation were evident, C. siliqua is resistant against UV-B radiation damage at the level applied.     

Effect of pupation environment on the quality of pupae and adults of the Mediterranean fruit fly

When mature larvae of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) pupated in bran rather than naked there was an increase in adult eclosion, but no difference in 9 day pupal weight, 9 day lipid content, or flight ability. There was no difference when pupation occurred at 20 or 25°C. Pupation in sand at 20°C caused severe mortality, while pupation in sand at 25°C did not. Data are presented which favour naked pupation over pupation in any medium, and evidence is presented which indicates that collection of mature larvae in a rotary tumbler rather than by the conventional popping method is economically preferable and is without significant biologically adverse effects.

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Résumé Si des larves mûres de Ceratitis capitata se nymphosent dans du son ou à l'air libre, dans le premier cas le taux d'éclosions est plus élevé, mais le poids et la teneur en lipides au neuvième jour de nymphose ainsi que l'aptitude au vol sont identiques dans les deux. Il n'y a pas de différences pour les pupaisons à 20°C et 25°C, mais la pupaison dans le sable à 20°C provoque une forte mortalité, tandis qu'à 25°C le sable n'a aucun effet. Les résultats obtenus sont favorable à une pupaison à nu plutôt que dans un substrat, et des arguments sont apportés montrant que la collecte des larves mûres dans un culbuteur rotatif ne provoque significativement pas plus d'effets nocifs que la méthode classique du saut.

     

Spread of the introduced tropical green alga Caulerpa taxifolia in northern Mediterranean waters

The first report of Caulerpa taxifolia in the Mediterranean is from 1984. The alga was found on the rocky shore at Monaco, below the Oceanographic Museum, where it had been on display in tropical aquaria. Within five years, there was an abundance of C. taxifolia on the shores around the first point of observation. In 1987, C. taxifolia appeared on the French coast, 3 km east of Monaco, at Cap Martin. By late 1991, 30 ha of shore in the vicinity of Monaco was covered with the alga. New points of colonization were in Livorno, Italy, 240 km east of Monaco, and to the west at Agay, Le Lavandou, Hyères, Toulon, Les Lecques, Saint Cyprien, 50 to 370 km from Monaco. The westernmost point of colonization, noted in September 1992, was 600 km from Monaco, at Majorca (Balearic island, Spain). Most types of substrata, between 0 and 50 m depth, are susceptible to colonization by C. taxifolia. Seaweed and seagrass populations on the coasts of Monaco and Cap Martin have been significantly reduced or destroyed because of invasion by C. taxifolia.     

Veronica: Parallel morphological evolution and phylogeography in the Mediterranean

The genus Veronica s. lat. comprises about 450 species (including about 180 species from the southern hemisphere Hebe-complex), many of which grow in the Mediterranean area. Their extreme variability in morphology, life form and habitats has led to many suggestions regarding evolution and biogeography. Difficulties arise from parallel syndromes, widespread among alpine species and lowland perennials, and particularly among annual species of the genus. We have used sequences of the plastid trnL-F region and nuclear ribosomal ITS sequences to differentiate between different clades of Veronica and reveal cases of parallel evolution. Based on this data, cases of parallel evolution have been found in biogeographical patterns among the alpine species of Veroniceae, in which species from European mountains have affinities to those in the Central Asian/Himalayan region whereas alpine species from Turkey are probably more recently derived from lowland southwestern Asian taxa. Different subspecies of Veronica bombycina gained their characteristic morphology independently and parallel in adaptation to their alpine environment. Pinnatifid leaves have been gained parallel in perennial grassland species of Veronica. Finally, parallel evolutionary trends in many characters, not only morphological but also molecular characters, are common among annual species of Veronica.We wish to thank the Studienstiftung des deutschen Volkes for a doctoral scholarship to DCA and the Spanish Ministerio de Ciencia y Tecnologia for a postdoctoral grant (programa FPI) to MMO. This work was partially supported by the Junta de Castilla y Leon and the European Union (FSE) through the research project SA117/01. We also thank Prof. F. Ehrendorfer for critical comments and valuable discussions. Further, DCA thanks Daniela Hanfland and Yoshiki Nakamoto for help in the field. Manfred A. Fischer, Lena Struwe, Bernhard Dickore, Christoph Dobes, Eberhard Fischer, Niels Köster, Gerald Schneeweiss, Tod Stuessy, Tim Utteridge and Matsugo Yokota have provided plant material for this study.     

Ecogeography of the grass genusHelictotrichon (Poaceae: Aveneae) in the Mediterranean and adjacent regions

The geographical distribution of the grass genusHelictotrichon in the Mediterranean Region is analysed and mapped for 33 taxa. Based on only a single life form (perennial herb), a variety of edaphically, climatically and altitudinally differently adapted species complexes has evolved in the area. Most of these complexes show west-east disjunctions and contain geographically, sometimes even edaphically vicarious taxa with complementary distribution. A transition from mesomorphic to xeromorphic habit occurred independently in different species groups and led to the establishment of the modern Mediterranean taxa which are in part highly polyploid derivatives of more mesophilic diploids. The significance of polyploidy, patterns of parapatric and sympatric distribution, biogeographical borders, and centres of species diversity are discussed in context with the history of the Mediterranean vegetation. New combinations are:Helictotrichon setaceum subsp.petzense, H. pratense subsp.lusitanicum, H. praetutianum.     

Consistent performance of invasive plant species within and among islands of the Mediterranean basin

Since the success of an invasive species depends not only upon its intrinsic traits but also on particular characteristics of the recipient habitat, assessing the performance of an invader across habitats provides a more realistic analysis of risk. Such an analysis will not only provide insights into the traits related to invasiveness, but also the habitat characteristics that underpin vulnerability to invasion that, taken together, will facilitate the selection of management strategies to mitigate the invader’s effect. In the present study, we considered the Mediterranean basin islands as an excellent study region to test how the same invasive species perform in different habitats within a single island, and to scale up differences among islands with similar climate. We tested how the performance of three widespread plant invaders with clonal growth but contrasting life-history traits, a deciduous tree Ailanthus altissima, a succulent subshrub Carpobrotus spp., and an annual geophyte Oxalis pes-caprae, varied depending upon the species identity, habitat, and invaded island. The environmental parameters considered were habitat type, elevation, species diversity in the invaded plot, and several soil traits (% C, % N, C/N, pH, and relative humidity). The study documents that the performance of these three important and widespread plant invaders is dependent mainly on species identity, and less upon the invaded island’s general features. Likewise, differences in performance among habitats were only significant in the case of Ailanthus, whereas Carpobrotus and Oxalis appear to perform equally well in different environments. Ailanthus thus appears to have a broader spectrum of invasiveness, being able to invade a larger number of habitat types. On the contrary, Carpobrotus spp. have not yet invaded habitats different from those where the species have been originally introduced and where they are still commonly spread by humans. Oxalis distribution is mainly related to agricultural activities and disturbed sites, and the total area infested by this geophyte may be more reflection of the extent of suitable habitats than of invasiveness or ecological impact. Our results confirm the potential for these species to significantly alter the functioning of ecosystems in the Mediterranean islands and highlight the risk to other islands not yet invaded.     

The American brine shrimp as an exotic invasive species in the western Mediterranean

The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France, the Iberian Peninsula and Morocco) contain autochthonous forms of the brine shrimp Artemia, with parthenogenetic diploid and tetraploid strains coexisting with the bisexual species A. salina. Introduced populations of the American brine shrimp A. franciscana have also been recorded in these Mediterranean environments since the 1980s. Based on brine shrimp cyst samples collected in these countries from 1980 until 2002, we were able to establish the present distribution of autochthonous brine shrimps and of A. franciscana, which is shown to be an expanding invasive species. The results obtained show that A. franciscana is now the dominant Artemia species in Portuguese salterns, along the French Mediterranean coast and in Cadiz bay (Spain). Co-occurrence of autochthonous (parthenogenetic) and American brine shrimp populations was observed in Morocco (Mar Chica) and France (Aigues Mortes), whereas A. franciscana was not found in Italian cyst samples. The results suggest these exotic A. franciscana populations originate as intentional or non-intentional inoculations through aquacultural (hatchery effluents) or pet market activities, and suggest that the native species can be rapidly replaced by the exotic species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Epibiontic and endobiontic polychaetes of Geodia cydonium (Porifera,Demospongiae) from the Mediterranean Sea

Polychaete assemblages associated to the sponge Geodia cydonium were investigated at two sampling sites in the Mediterranean Sea: Porto Cesareo Basin (Apulia) and Marsala Lagoon (Sicily), both characterized by sheltered hydrodynamic conditions. Samples were seasonally performed during 1997, in order to compare the assemblages coming from the two localities studied, considering separately the internal and external tissues of the sponge, and with the aim of evaluating the influence of sponge size on polychaete colonization. The examined sponge is characterized by a peculiar stratification of its tissues: an external thick and hard layer, the cortex, and an internal softer one, the choanosome. Statistical analysis showed that this was the main factor controlling polychaete assemblage, with the internal tissue, less rich and diversified, appearing impoverished with respect to the external layer. A similarity in species composition was observed between sites, even though some differences were evidenced in the abundance of some species, mainly reflecting differences in local environmental conditions. Species richness and density increased with the increasing sponge size. Such a situation is particularly evident at Porto Cesareo, where sponges are covered by an algal layer which is particularly rich on the largest specimens, thus suggesting that most of the species of polychaetes were linked more to the neighbouring environment than to the sponge itself.     

Notes on the distribution and biology of the deep-sea crab Bathynectes maravigna (Brachyura: Portunidae) in the Mediterranean Sea

Data on the distribution and biology of the deep-sea portunid crab Bathynectes maravigna are reported for the Mediterranean Sea, based on several fisheries research surveys. Densities are low and, therefore, biological data are scarce. In the western Mediterranean, the species is much commoner in Alborán Sea than in the Catalano-Balearic Sea. Occurrences are also scarce in the southern Adriatic and northwestern Thyrrenian Sea, as well as in the Ionian Sea. The Alborán Sea and the seas surrounding the southern Italian peninsula are the areas where densities are the highest. The occurrence depth range was found to be 245–786 m, but most of the occurrences took place deeper than 500 m. Sizes ranged between 9 and 51 mm carapace length in males and between 12 and 51 mm in females. Ovigerous females have been only reported in October–December and March–May. Eighty three percent of both males and females are right-handed. Sexual dimorphism was present in cheliped length with males having longer chelae than females. The species appears to be much commoner in those areas where Atlantic influence is the highest.     

Combined effects of enhanced UV-B radiation and additional nutrients on growth of two Mediterranean plant species

Seedlings of two Mediterranean plants, the slow-growing, evergreen sclerophyll Ceratonia siliqua L. and the fast growing drought semi-deciduous Phlomis fruticosa L., were grown for one year in the field at ambient or ambient plus supplemental UV-B radiation (equivalent to a 15% ozone depletion) and two levels of applied fertilizers (NPK). The effects on growth, morphological, anatomical and physiological parameters were measured at final plant harvest. Additional nutrients increased leaf nitrogen, improved growth and reduced the root/shoot ratio in both plants, yet these effects were more pronounced in the fast growing P. fruticosa. A nutrient-induced increase in chlorophyll content was also observed in this plant. The growth responses to UV-B radiation were different for the two species. Growth in C. siliqua was not affected by UV-B radiation at both nutrient levels and the same was true for P. fruticosa at low nutrients. However, at the high nutrient level, supplemental UV-B radiation improved growth in P. fruticosa, indicating a strong interaction between the treatments. Photosystem II (PSII) photochemical efficiency, methanol-extractable UV-B absorbing capacity, total phenolics and tannins were not affected by either treatment in both plants. It is concluded that nutrient levels can strongly modify the UV-B radiation effects on growth of P. fruticosa. We presume that this may be correlated to the fast growing habit of this species.     

Invasion of alien macroalgae in different Mediterranean habitats

The study evaluated different macroalgal invasions in the main Mediterranean coastal habitats on hard bottom. Biodiversity, species composition and structure of macroalgal assemblages were compared among non-invaded areas and areas invaded by the Chlorophyta Caulerpa racemosa var. cylindracea and by the turf-forming Rhodophyta Womersleyella setacea in three different habitats: shallow rocky bottom, deep rocky bottom and dead matte of the seagrass Posidonia oceanica. Results showed that alien macroalgae constituted a relevant component of benthic assemblages in invaded areas of the Mediterranean Sea. Assemblages invaded by Womersleyella setacea and Caulerpa racemosa showed lower values of diversity and large differences in the structure and species composition related to non-nvaded assemblages. The species that mostly suffered from invasion were erect species reproducing sexually; moreover, the dominance of W. setacea led to low abundance of native filamentous algae, while C. racemosa colonization seemed particularly threatening for encrusting algae. All the studied habitats appeared highly invasible by alien macroalgae, even if W. setacea appeared more invasive in deeper habitats, while colonization of C. racemosa seemed more serious in shallower habitats; the dead matte of P. oceanica represented a suitable substrate for the spread of both species. Differences among assemblages in different habitats were reduced in invaded areas.     

Anchusella, a new genus ofBoraginaceae from the Central-Eastern Mediterranean

The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits.     

Cytogenetical evidences for hybrid structure and origin of diploid and triploid shallots (Allium cepa var.viviparum,Liliaceae) from Dalmatia (Croatia)

Two viviparous strains of common onion (Allium cepa) denoted asAllium cepa var.viviparum (syn.Allium ×proliferum), traditionally cultivated in the seaside regions of Croatia were found to be diploid (2n = 2x = 16) and triploid (2n = 3x = 24), respectively. The triploid cultivated onion Ljutika has not been previously reported in Europe. Using Feulgen and Giemsa C-banding methods both karyotypes were shown to be of hybrid constitution. Results obtained in this work indicate that Dalmatian viviparous onions arose from spontaneous hybridization ofA. cepa withA. fistulosum.