Struttura e periodismo dei popolamenti a Cystoseira(Fucophyceae,Fucales) del Mediterraneo

Abstract

News on both the structure and the periodism of the communities with Cystoseira from the Mediterranean Sea based on literature data, are presented.

In order to a better knowledge of such communities, the opportunity of a standardized methodology based on a preliminary study of the qualitative minimal area, on monthly samples to be carried out throughout a year as well as on observations on the vertical distribution of species within the community, is suggested.     

Inventario delle Corallinales del Mar Mediterraneo: considerazioni tassonomiche

Abstract

Inventory of Corallinales of the Mediterranean Sea: taxonomic aspects. - The aim of the present work is the drawing up of a critical inventory of Corallinales of the Mediterranean Sea. This research has been based upon a census of 320 works published since 175 years, upon direct collections and sample exchanges. A census of 88 species of Corallinales (with forms and varieties), made up on the basis of about 5000 records, has been taken. 34 of the 88 species are considered “species dubiae aut rariter inventae”, it has been reported also “species inquirendae” and “species addendae”. From this census it results that there are some taxonomic problems about genera attributions (Lithophyllum, Pseudolithophyllum, Titanoderma, Neogoniolithon, Spongites, Goniolithion, Leptophytum), species attributions of articulated Corallinales (Corallina elongata, C. officinalis e Haliptilon squamatum) and non-articulated Corallinales (Fosliella ischitana, Lithophyllum (Titanoderma) trochanter, Spongites fruticulosus). Definition of these taxonomic attributions might condition not only studies of phytogeographical distribution of these algae but also every successive interpretation.     

Avian brood parasitism in a Mediterranean region: hosts and habitat preferences of Common Cuckoos Cuculus canorus

Capsule Cuckoos in Italy support the ‘host preference’ hypothesis.

Aims To identify the species parasitized in a Mediterranean area, in Italy; to quantify the frequency of parasitism on each host species; and to determine whether some species and/or habitat types are parasitized more than expected from a homogeneous distribution.

Methods Nest records dating from 1865 were compiled from literature, nest card programmes, and personal communication with ornithologists working in the region. Comparisons of parasitism frequencies were made among and within habitats for all cuckoo hosts.

Results The most frequently parasitized hosts were Great Reed Warbler, European Robin, Marsh Warbler, Redstart, and Reed Warbler. The highest number of parasitized species was in anthropic areas (15 host species), whereas wetlands supported the highest number of parasitized nests (471).

Conclusion Cuckoos select a different suite of hosts in Italy from those in continental Europe, but this was not always explained on the basis of different geographical distribution. Results support the ‘host preference’ hypothesis. We suggest further analyses to avoid over‐ or underestimates of parasitism on each host species when parasite preferences are examined.     

Analisi citologica di alcune specie del genere Vicia

Abstract

Karyology of some species of Vicia. The species studied are: Vicia articulata, Vicia monantha, Vicia narbonensis and Vicia ervilia.

The chromosome number 2n = 14 counted for the first three species agrees with that reported in literature; that of Vicia monantha (2n=14) agrees with that quoted by Heitz, while Senn finds 2n=12.

Karyotypes of V. narbonensis and V. ervilia show appreciable differences from those reported in literature.     

Effect of salinity,temperature and hypersaline conditions on the seed germination in Limonium mansanetianum an endemic and threatened Mediterranean species

Abstract

Limonium mansanetianum is catalogued as critically threatened (CR) species and it is included in Valencian Catalogue of Threatened Plant Species. Limonium mansanetianum is a gypsicolous species, which only lives in a restricted area to south-centre of Valencia province (Spain). The species is a low-branched woody shrub with summer flowering. The influence of incubation temperature (10°, 15°, 20° and 25°/20?°C) and salinity (0%–3.0% NaCl) on seed germination of L. mansanetianum was studied. Best seed germination was obtained in distilled water controls. Seed germination decreased with an increase in salinity and few seeds germinated at 2.5% and 3.0% NaCl. Optimal temperature regime for germination was 15?°C where germination in 0.5% and 1.0% NaCl was not affected. Recovery and hypersaline conditions experiments showed that L. mansanetianum seeds displayed a greater tolerance to high salinity and temperature stress before germination.     

A new species of Limonium (Plumbaginaceae) from Soqotra (Yemen)

Abstract

Limonium guigliae, from the island of Soqotra (Yemen) is described. This new species, close to L. paulayanum differs from it by its size, flower morphology and ecology.     

Primo contributo alla conoscenza dei laghi appenninici meridionali di alta quota. Il fitoplancton dei laghi del massiccio del Monte Sirino (Appennino Lucano)

Abstract

A preliminary account on some mountain lakes of the Southern Apennines. Phytoplankton investigation on three ponds of the Monte Sirino (Basilicata).—Phytoplankton standing crop and species composition have been studied in three ponds of the Southern Apennines. The observations carried out throughout ten months in 1975, showed a great number of species present in the Remmo pond, mainly diatoms, desmids, green algae, and blue-green algae. In the Sirino pond only diatoms and Chrysophyceae were present.

In comparison, in the Zapano pond, the phytoplankton was scarcely represented but the occurrence of some species of green algae may suggest a eutrophic water condition. On the basis of the peculiarities both of species composition and biomass, the major water bodies may be considered oligotrophic.     

Rinvenimento del polline di Keteleeria in alcuni depositi quaternari dell'Italia centro-settentrionale

Abstract

THE DISCOVERING OF THE KETELEERIA'S POLLEN-GRAIN IN SOME QUATERNARY DEPOSITS OF THE CENTRAL AND NORTHERN ITALY. — The Author observes the specy of Keteleeria with the pollen analysis executed on deposits of turfys, clays and brown coals of some Umbro-Marchigiano and of the Po Plain localyties.

The Keteleeria to-day is living only in China and Japan; in Italy it was living also during the early and middle Pleistocene.     

Secondo Contributo Alla Conoscenza Dello Sviluppo Embriologico del Genere Centaurea L. (Asteraceae). Centaurea Horrida Bad

Summary

The Author has studied the embryological development of Centaurea horrida Bad., pure pliocenic endemisms of Sardinia and has established that:

1°) the cromosomic number of the species is: 2n = 18.

2°) the genesis of microspores is of simultaneous type;

3°) The archesporium is constituted of one cell only seldom accompanied by a basal cell;

4°) the development of the female gamethophyte is of normal type;

5°) even showing cases of degenerated antipodal cells, the species has a marked tendency to the polyantipody, sometimes also characterized by a strong hypertrophy of its cells;

6°) in the species the contemporary germination of some megaspores in the same ovule is enough frequent;

7°) there are also some cases of coesistence of some gamethophytes in their different stages of development;

8°) the phenomenon of «multiple oospheres» and of «multiple synergidae» may happen;

9°) in some ovules, near the egg-apparatus, cells of two or four nuclei may be found.

For these last ascertainments (8° and 9°) the Author makes the hypothesis that it may be probably an anomalous prolification of micropylar nuclei, or asynchronous development, for delayed germination of some micropylar megaspores producing primary stages of gamethophyte.

Moreover the Author has the opportunity to bring into evidence:

10°) a case of ovular teratology represented by the extraovular development of an adult gamethophyte very similar to those previously found by the Author himself in Petasites fragrans;

11°) frequent cases of regretion of female sexuality, founding that about the 10% of the flowers examined were functionally male. The Author has fronted the possibility of the existence, in Asteraceae, also of the type of inflorescence where «flowers are all tubulated: the marginal ones neuter, the others or hermaphrodite or hermaphrodite and male».     

On Cannabis indica,Indian hemp

Background: The South Aegean Volcanic Arc (SAVA), one of the most notable geological structures of the Mediterranean Sea, is floristically well known. Nevertheless, the factors that contribute to shaping the plant species richness of the SAVA remain unclear.

Aims: To investigate the factors that affect plant species richness and identify plant diversity hotspots in the SAVA and other central Aegean islands.

Methods: We used stepwise multiple regression to test the relationship between a number of environmental factors and plant species richness in the SAVA, as well as the residuals from the species–area linear regressions of native, Greek and Cycladian endemic taxa as indicators of relative species richness.

Results: The area was confirmed to be the most powerful single explanatory variable of island species richness, while geodiversity, maximum elevation and mean annual precipitation explained a large proportion of variance for almost all the species richness measures. Anafi, Amorgos and Folegandros were found to be endemic plant diversity hotspots.

Conclusions: We have demonstrated that geodiversity is an important factor in shaping plant species diversity in the Cyclades, while mean annual precipitation, human population density and maximum elevation were significant predictors of the Greek endemics present in the Cyclades. Finally, Anafi was found to be a plant diversity hotspot in the South Aegean Sea.     

Annotated check-list of the family Tachinidae (Diptera: Calyptratae: Oestroidea) in the Canary Islands

Summary

A commented check-list of the tachinid species inhabiting the Canary Islands (Spain) is provided, with special emphasis on hosts species and floral resources. Nine new local records are provided and Cylindromyia rufipes is reported for the first time for the Canary Islands, thus increasing the species number to 52. Zoogeographic analysis of the area revealed that there are differences in chorotype composition among islands, with the easternmost islands being richer in Mediterranean species and poorer in endemics. These differences may be due to ecological differences between the easternmost island and the remaining islands. Relevance regarding influence of tachinid as pollinators is discussed.     

Adding ecology into phylogeography: ecological niche models and phylogeography in tandem reveals the demographic history of the subalpine warbler complex

Capsule: This study documents evidence of interglacial refugia during the Last Interglacial for birds in the Mediterranean region, and emphasizes the importance of the Last Interglacial on the geographic distribution and genetic structure of Mediterranean species.

Aims: We focused on the historical biogeography of the subalpine warbler complex: Subalpine Warbler Sylvia cantillans and Moltoni’s Warbler Sylvia subalpina; we tested if this Mediterranean bird complex shared a similar demographic fate as the present-day widespread species in the temperate zones of Europe, through the late Quaternary glacial-interglacial cycles.

Methods: An ecological niche model was developed to predict the geographic distribution of the subalpine warblers under the past (the Last Interglacial and the Last Glacial Maximum) and the present bioclimatic conditions. Additionally, Bayesian Skyline Plot analysis was used to assess effective population size changes over the history of the subalpine warbler complex.

Results: During the Last Glacial Maximum, the subalpine warblers almost reached their current distribution in the Mediterranean region; yet, unlike the widespread temperate bird species, they survived the Last Interglacial in allopatric refugia in the Mediterranean region.

Conclusion: A unique biogeographic pattern was revealed, indicating the importance of the Last Interglacial on current distributional patterns and demographic histories of common bird species in the Mediterranean region. This study suggests that Mediterranean biogeography is far more complex than previously assumed, and so deserves further study and more attention.     

Studio Floristico e Fitogeografico Delle Piccole Isole della Sardegna Nord-Occidentale

Summary

The author has studied the flora of the little islands of Northe-West Sardinia. In a former note he has referred on Isola Piana, in this one he refers on: Isola Rossa, Isola dei Porri, and Isola Foradada.

After having done the census of the species, notifying particularly the dominant ones and after having put in evidence the principal plant communities he kept his attention on some endemic species two of which are probable endemisms new to the science: Olea europaea L. v. latifolia (mihi) and Smilax aspera L. v. inermis (mihi), coming to the conclusion:

1°) The study should confirm the hypothesis that in the little islands may be manteined species, or ancient in regression, or recent in variation the recessive characters of which would be substracted to overcome of the dominant charaters of a largest population;

2°) The florae of the four islands, for theier geographical position are the expression of the Mediterranean half-dry climate;

3°) They present their plant communities from which springs the autonomy of the different «Ecoidi» with theier different predominance established by the equilibrium attained in them.     

Note Sistematiche ed Osservazioni Fitosociologiche Sulle Laminariales del Mediterraneo Occidentale

Abstract

Laminariales from western Mediterranean Sea: taxonomical and phytosociological study. — Laminariales found in the Mediterranean Sea are: Laminaria rodriguezii Bornet, L. ochroleuca De la Pylaie, Saccorhiza polyschides Batters, Phyllaria reniformis Rostafinski, Ph. purpurascens Rostafinski. By diving technique L. rodriguezii and Ph. reniformis was collected off isles Ustica, Stromboli, Pianosa and Montecristo (Thyrrenean Sea) from 50 to 90 mts depth in the coralligenous biocoenose; L. ochroleuca and Ph. purpurascens between Scilla and Ganzirri in the straits of Messina from 45 to 85 mts depth in facies of deep rheophilous biocoenoses; S. polyschides and Ph. reniformis near Villa S. Giovanni and Messina in the facies with Ulva-Corallina-Dictyopteris of photophilous algae biocoenose. Algal vegetation associated with these species of Laminariales in the straits of Messina is characterized by Atlantic-temperate elements (Ulva olivascens, Halurus equisetifolius, Cryptopleura ramosa, Giffordia hincksiae, etc…).     

Cytogenetics Status of Four Ctenomys Species in the South of Brazil

This report is a review of 20 years of cytogenetics studies in tuco-tucos from the south of Brazil and the implications for the evolution of these species as well as the relation of these data with the geological history of the Coastal Plain of southern Brazil. Two forms of Ctenomys torquatus, 2n = 44 and 46, are separated by a geographic barrier. Ctenomys flamarioni shows a constant karyotype (2n = 48) and presents high variability in FN due to constitutive heterochromatin variation. Ctenomys minutus presents the highest chromosomic variation among the species in the south of Brazil (2n = 42–50) with three chromosomic hybrid zones. Ctenomys lami, like C. minutus, presents a high chromosomic variation due to fusions and fissions of chromosome pairs 1 and 2. Both species present a close evolutionary relationship, including a chromosomic hybrid zone.     

Physiological and morphological characterisation of Limonium species in their natural habitats: Insights into their abiotic stress responses

Background and aims

Morphological and biochemical traits of four halophytes of the genus Limonium were analysed in plants sampled from salt marshes in SE Spain. This work aimed to explore the mechanism(s) behind the adaptation of these species to stressful habitats, with particular emphasis on responses to drought.

Methods

Plants of each species together with soil samples were collected in summer, which is the most stressful season in the Mediterranean. Soil parameters and plant morphological traits were determined, and the levels of several biochemical stress markers in plants were measured using spectrophotometric assays. A multivariate analysis was performed to correlate soil and plant data.

Results

Morphological characteristics regarding the underground system topology and several biochemical traits (higher foliar Ca²⁺, sucrose and glucose, and lower proline, glycine-betaine and fructose) clearly separate L. santapolense individuals from plants of the other three species.

Conclusions

Drought tolerance of L. santapolense in the field is mostly dependent on morphological adaptations: when growing in an arid location, plants of this species develop long taproots that can extract water from the deep, moist layers of the soil.

     

Aphyllophorales del Bosco della Mesola (Ferrara)

Abstract

Aphyllophorales from Mesola Forest (Ferrara) Italy—The present check-list is the first contribution to the knowledge of Aphyllophorales growing in the area of the Mesola Forest. The paper deals with 72 species of Aphyllophorales collected during the years 1980-1983. A further contribution will complete the picture of the Aphyllophorales flora which is particularly interesting and abundant in the forest.

Some of the species listed in the present paper are quite interesting since they are uncommon: Meruliopsis hirtellus and Oxyporus latemarginatus are new to Italy; Flaviporus semisupiniformis is the first European finding and the second world collection.     

Toxic dinoflagellates in the Mediterranean sea

Abstract

A review of the distribution of toxic dinoflagellates and related toxic events in the Mediterranean Sea is provided. Diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP) are the main seafood contaminations, that have been reported since 1987. In 1994 four lethal cases for PSP were reported in Morocco. DSP seems to be restricted in the Northern part of the basin, while PSP contamination presents a wider distribution. Potentially DSP species, belonging to the genus Dinophysis, are widely distributed in the Mediterranean Sea, suggesting a wider extension of this contamination. The lack of monitoring programs in the Southern Mediterranean could be responsible of DSP overlooking. The species responsible for PSP are Gymnodinium catenatum in the Alboran Sea and Alexandrium minutum in various parts of the basin. Ichtyotoxic effects, due to Gymnodinium and Gyrodinium species, have been sporadically reported in some Mediterranean areas.     

Plant functional strategies and environmental constraints in Mediterranean high mountain grasslands in central Spain

Background: The relationship between plant traits and environmental factors will be of value in understanding of functional strategies that plants have developed to cope with the environmental constraints on plant life in Mediterranean high mountain ecosystems.

Aims: The aims of this study were (1) to explore the variation in plant traits in relation to environmental variability; (2) to analyse the functional strategies of species; and (3) to assess the habitat constraints for the species in the study area.

Methods: We sampled the floristic composition of 76 1 m?×?1 m plots on five summits over 2,100 m above sea level in the mountains of the Sistema Central, Spain. Soil properties and temperature and grazing disturbance parameters were recorded. Eight plant traits were assessed in 21 species. Environmental variability and the co-variation of functional traits were analysed by RDA and PCA, respectively. Plant traits and environmental variability were related using fourth-corner analysis.

Results: Traits related to resource acquisition, such as leaf size and N concentration, varied with soil temperature and estimated summer water availability. Leaf dry matter content was found to be related to estimated water availability and soil pH. Seed mass was a factor of snow cover duration and water availability, and clonality to the duration of the vegetative period and estimated water availability. Grazing disturbance was related to the mean plant height of the species.

Conclusions: The results suggest that low temperatures, rather than water shortage, may be the principal limiting factor for resource acquisition in plants. Nevertheless species establishment is limited by water shortage during summer in these Mediterranean high mountain communities.     

Epiphytic bryophytes in harsh environments: the Juniperus thurifera forests

Abstract

The forests of Juniperus thurifera are peculiar ecosystems that typically grow on mountains and highplateaux of the western Mediterranean basin with dry and continental climates. Some previous surveys suggested that these forests house a rather distinctive epiphytic bryophyte flora. Epiphytic bryophyte communities were systematically sampled in 19 representative juniper forests, for the first time spanning all the distribution area of this conifer. The flora consists of 44 species (32 acrocarpous mosses, 10 pleurocarpous mosses and 2 liverworts). Orthotrichum species are the most frequent and abundant in most of the sampled localities, including some uncommon taxa such as Orthotrichum vittii which shows a clear association with J. thurifera. Epiphytic bryophyte communities on this species were highly homogeneous, although they can be arranged into different groups in response to environmental conditions. Typically, the epiphytic communities of the Mediterranean juniper forests comprise a distinct combination of xerophytic taxa that enhances the interest of these ecosystems and provides new fields for their research and conservation.