First record of Potamogeton×salicifolius for Italy,with isozyme evidence for plants collected in Italy and Sweden

Abstract

Potamogeton×salicifolius, a hybrid between P. lucens and P. perfoliatus, is identified as a new taxon for Italy. This is the first record of this hybrid from southern Europe. The Italian sample was studied in cultivation and compared with a living specimen of P.×salicifolius from Sweden, where the hybrid is rather widespread. In addition to morphological features, the most compelling evidence for the hybrid origin of these plants came from the isozyme analysis. The additive “hybrid” banding patterns of the five enzyme systems studied indicate inheritance from P. lucens and P. perfoliatus. The distribution of this hybrid in Europe coincides with the areas most severely affected by the Late Pleistocene glaciation. The relationships between environmental conditions, history of the habitat and rise of hybrids are discussed.     

Assessing the effects of forest management on epiphytic lichens in coppiced forests using different indicators

Abstract

Epiphytic lichens are one of the taxonomic groups most sensitive to forest management. Nevertheless, they have not yet been exhaustively included in the assessment of Sustainable Forest Management. This work aimed at evaluating the effects of forest management on epiphytic lichens in coppiced forests, exploring the spatial patterns of diversity and the composition of communities. Moreover, the goal was to compare the performance of four potential indicators for monitoring the effects of forest management on epiphytic lichens: total lichen diversity, species associated with intensive management, species associated with aged coppiced woodlands and Indicator Species Ratio (ISR). In humid Mediterranean Liguria, 50 sampling units were chosen in Castanea sativa and deciduous Quercus spp. forests subjected to different forest management practices: intensively managed coppice and aged coppice/high forest. The effect of forest management was evident in terms of species composition, since it was possible to find significantly associated species for each of the two management types. At each sampling site, the four indicators were calculated using Indicator Value Analysis and compared through correspondence analysis. The ISR was shown to be a more effective indicator, being independent of floristic composition and the occurrence of rare species.     

Azione della Cinetina sulla Degradazione della Clorofilla in Foglie di Orzo Irradiate

Abstract

The effects of kinetin on chlorophyll breakdown in irradiated barley leaves. — Kinetin is shown to inhibit the breakdown of chlorophyll in isolated barley leaves. Moreover the kinetin is shown to inhibit, even if with lower effect, the chlorophyll breakdown in irradiated barley leaves. This possible correlation of these observations, with kinetin promoted protein synthesis is suggested.     

A Novel Alveolate in Bivalves with Chemosynthetic Bacteria Inhabiting Deep‐Sea Methane Seeps

It has recently been unveiled that a wide variety of microbial eukaryotes (protists) occur in chemosynthetic ecosystems, such as hydrothermal vents and methane seeps. However, there is little knowledge regarding protists associated with endemic animals inhabiting these environments. In the present study, utilizing PCR techniques, we detected fragments of the small subunit ribosomal RNA gene (SSU rRNA gene) from a particular protist from gill tissues of a significant fraction of the vesicomyid clams Calyptogena soyoae and C. okutanii complex and of the mussel Bathymodiolus platifrons and B. japonicus, all of which harbor chemosynthetic endosymbiont bacteria and dominate methane seeps in Sagami Bay, Japan. Based on the phylogeny of SSU rRNA gene, the organism in question was shown to belong to Alveolata. It is noteworthy that this protist did not affiliate with any known alveolate group, although being deeply branched within the lineage of Syndiniales, for which the monophyly was constantly recovered, but not robustly supported. In addition, the protist detected using PCR followed by sequencing was localized within gill epithelial cells of B. platifrons with whole‐mount fluorescence in situ hybridization. This protist may be an endoparasite or an endocommensal of Calyptogena spp. and Bathymodiolus spp., and possibly have physiological and ecological impacts on these bivalves.     

Distribution,ecology and conservation survey on Trifolium michelianum Savi (Fabaceae) in Sicily (Italy)

We report the identification of four residual stations for Trifolium michelianum Savi (Fabaceae) in Sicily, whereas the species was documented to be extinct at the Gorgo Cerro station (western Sicily), the only locality previously reported in the literature. In addition to an update on the distribution of the species, a survey on the new Sicilian populations led to their biological, ecological and phytosociological characterization, as well as to an assessment of the risk factors. The species, here relegated to the limit of its distribution area, occurs in particularly sensitive and vulnerable environments, such as the “Mediterranean temporary ponds”, considered “priority” by the Council Directive 92/43/EEC. Moreover, a new Sicilian association (Trifolio micheliani–Glycerietumspicatae ass. nova), framed in the alliance Glycerio-Sparganion (class Phragmito-Magnocaricetea), is described.     

Halocnemum M. Bieb. vegetation in the Mediterranean Basin

The aim of the article is the syntaxonomic interpretation of hyperhalophilous woody or semi-woody vegetation with Halocnemum M. Bieb. along the coasts of the Mediterranean Basin. For this area, the two species of Halocnemum, H. strobilaceum (Pall.) M. Bieb. and H. cruciatum (Forssk.) Tod. are identified; their morphological characteristics, synonymy and distribution are here described. The study carried out of particular aspects of the plant morphology and the micromorphological characteristics of the seeds collected from different places in the Mediterranean allows to better differentiate the two species. Vegetation studies already done in many communities of the Mediterranean by several authors threw into great confusion because only H. strobilacem has been recognized as a dominant species. As regards the syntaxonomic analyses of the vegetation, the authors refer to the proposals already made by various scientists for the vegetation of inland salt basins of Eurasia and the Irano-Anatolian area, who suggested the classes Kalidietea foliate and Halocnemetea strobilaceiirano-anatolica, respectively. Conversely, in the Mediterranean Basin, the vegetation study is present only in coastal areas where it is considerably impoverished in the number of species. Therefore, the authors propose to include hyperhalophilous, woody and fruticose vegetation in the class Sarcocornietea fruticosae. However, the phytosociological and ecological diversity is highlighted proposing the order Halocnemetalia cruciati in which both the alliance Halocnemion strobilacei, for middle Eastern Europe, and the alliance Halocnemion cruciati, for North Africa with penetrations in the Western and Eastern Europe up to the Middle East coast, are included. This new interpretation has required the correction of the names of two associations (Frankenio corymbosae–Halocnemetum cruciati and Zygophylloalbi–Halocnemetumcruciati) and the proposal of two new associations Arthrocnemo machrostachyi–Halocnemetum cruciati and Halocnemo cruciati–Sarcocornietum fruticosae. A further proposal concerns the addition of the alliance Limoniastrion monopetali, previously included in the order Limonietalia, in the order Halocnemetalia cruciati.     

Types of names of Orobanche taxa described from North Africa

In the framework of the revision of the genus Orobanche (including Phelipaea) in the Mediterranean area, the original material for 31 names of new taxa described from North Africa by Ball, Battandier, Forsskål, Maire (partly with Emberger and Jahandiez), Persoon, Poiret and Pomel has been analysed. Typification is discussed, and where necessary types are designated. Accepted names and synonyms of the recognized taxa are given. Three species are illustrated, and one new combination (O. inexspectata) is proposed.     

Plant invasions in the rivers of the Iberian Peninsula,south-western Europe: A review

Aquatic and riparian ecosystems are known to be highly vulnerable to invasive alien species (IAS), especially when subjected to human-induced disturbances. In the last three decades, we have witnessed a growing increase in plant invasions in Portugal and Spain (Iberian Peninsula, south-western Europe), with very detrimental economic, social and ecological effects. Some of these species, such as the giant reed (Arundo donax L.) and the water hyacinth (Eichhornia crassipes (Mart.) Solms-Laub.), number among the world's worst weeds. We present an appraisal of this invasive alien river flora and the most problematic aquatic weeds. We review various aspects of invasion ecology, including spatial and temporal patterns of invasion, species invasiveness, species traits of invasive weeds, and relationships between human disturbance in rivers and surrounding areas and invasibility, and contextualize them in overall state-of-the-art terms. We also acknowledge the use of IAS as bioindicators of the ecological quality of rivers, wetlands and riparian zones. Remote-sensing tools and Geographic Information Systems for detecting and monitoring IAS in Iberian rivers are presented.     

The impacts of climate change and human activities on biogeochemical cycles on the Qinghai‐Tibetan Plateau

With a pace of about twice the observed rate of global warming, the temperature on the Qinghai‐Tibetan Plateau (Earth's ‘third pole’) has increased by 0.2 °C per decade over the past 50 years, which results in significant permafrost thawing and glacier retreat. Our review suggested that warming enhanced net primary production and soil respiration, decreased methane (CH₄) emissions from wetlands and increased CH₄ consumption of meadows, but might increase CH₄ emissions from lakes. Warming‐induced permafrost thawing and glaciers melting would also result in substantial emission of old carbon dioxide (CO₂) and CH₄. Nitrous oxide (N₂O) emission was not stimulated by warming itself, but might be slightly enhanced by wetting. However, there are many uncertainties in such biogeochemical cycles under climate change. Human activities (e.g. grazing, land cover changes) further modified the biogeochemical cycles and amplified such uncertainties on the plateau. If the projected warming and wetting continues, the future biogeochemical cycles will be more complicated. So facing research in this field is an ongoing challenge of integrating field observations with process‐based ecosystem models to predict the impacts of future climate change and human activities at various temporal and spatial scales. To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus biogeochemical cycles as well as about the role of microbes in these cycles.     

Application of two SH-based methods for metallothionein determination in mussels and intercalibration of the spectrophotometric method: laboratory and field studies in the Mediterranean Sea

Metallothionein (MT) induction is widely used as a biomarker of exposure to metals in mussels. The aims of the present work were first to compare the suitability of spectrophotometry and differential pulse polarography (DPP) for MT detection in mussels exposed to 200 ppb cadmium for 9 days in a laboratory experiment and in mussels sampled in different seasons from expected pollution gradients along the Mediterranean Sea; second, to intercalibrate the widely used spectrophotometric method using mussels from Saronikos Gulf. In the intercalibration of the spectrophotometric method, similar results (p>0.05) were obtained by two different research teams indicating a good reproducibility of the technique. However, polarographic and spectrophotometric methods gave significantly (p<0.05) different results in laboratory and field studies. In the laboratory experiment, MT values detected with DPP were nine times higher than with spectrophotometry. The results obtained by the two methods were significantly correlated. Both methods could discriminate between control and exposed mussels. In field studies, MT values obtained by DPP were 34–38-fold higher than with spectrophotometry, and MT concentrations measured by both methods were not correlated. This discrepancy could be due to several factors, including the low levels of bioavailable metals in the studied areas and the possibility that the different methods can measure MT isoforms differentially. Further work is needed to decipher the functions of MT isoforms in mussels. This information is relevant for the application of MT as a biomarker in biomonitoring programmes.