Contribution to the knowledge of Bulgarian serpentine grasslands and their relationships with Balkan serpentine syntaxa

Serpentine areas, including those in Bulgaria, are rich in endemic taxa, and still remain to be investigated phytocoenologically. We analyse the vegetation types in various sites and compare them with those in other Balkan countries. The main objectives were (1) to explore and describe the relationships between the vegetation in the serpentine areas investigated in Bulgaria with those in the Balkan Peninsula and (2) to explore and classify the diversity of vegetation in grasslands on serpentine rocks in eastern Rhodope, Bulgaria. The classic methodology of the Braun-Blanquet school was applied to the exploration of the vegetation. Average linkage method (unweighted pair group method with arithmetic mean) and principal coordinate analysis were used to evaluate floristic and synoptic similarities. As a result, the new endemic association Onosmo pavlovae-Festucetum dalmaticae was proposed. This association can be included in the alliance Alyssion heldreichii Bergmeier et al. 2009, newly described on serpentine rocks in northern Greece. Our data confirmed the existence of similar or vicariant endemic syntaxa (associations) on isolated serpentine terrains in northern Greece and south-eastern Bulgaria.     

Nickel localization on tissues of hyperaccumulator species of Phyllanthus L. (euphorbiaceae) from Ultramafic Areas of Cuba

Two species of perennial Phyllanthus (Euphorbiaceae) (Phyllanthus orbicularis and Phyllanthus discolor, both endemic to ultramafic areas of Cuba, and their natural hybrid, Phyllanthus xpallidus) were selected for metal localization microanalysis. Different plant tissues were analyzed by X-ray fluorescence, inductively coupled plasma—atomic emission spectroscopy, and scanning electron microscopy coupled with an energy-dispersive X-ray probe. All of the studied taxa are nickel (Ni) hyperaccumulators and significant concentrations of this element were found in different leaf and stem tissues. The highest Ni content was found in the laticifer tubes, whereas leaf epidermis Ni content resulted to be much more relevant in terms of total metal storage. Calcium and magnesium were found more evenly distributed in leaf and stem tissues.     

Impact of the non-indigenous shrub species Spartium junceum (Fabaceae) on native vegetation in central Spain

Aims The introduction of potentially invasive species through ornamental cultivation or for rehabilitation purposes is a serious environmental problem. They cause damage to biodiversity through loss, increased mortality or ' in situ ' selection phenomena in natural flora. Spartium junceum is a Mediterranean shrub that is not native in most areas of the Iberian Peninsula, although it is extensively grown for the rehabilitation of roadsides. We have investigated the effect on the native vegetation of an old S. junceum (Fabaceae) plantation in a conservation area in the centre of the Iberian Peninsula: the Cuenca Alta del Manzanares nature reserve in Madrid.Methods We compared S. junceum stands with the native nanophanerophytic Cistus ladanifer community at different ecosystem properties: soil properties, temporal soil seed bank contents, standing vegetation and net primary production of annual grasslands growing in these shrublands.Important findings The results highlighted S. junceum 's ability to become established in the new environment (marginal areas of the nature reserve) and ensure its successful growth. This is more apparent in northern and eastern exposures where this formation contacts with the core of the best conserved native vegetation in the nature reserve. Soils under Spartium showed a higher nitrogen content, indicating its capacity—in common with other legumes—to fix N, and conferring an advantage over Cistus, which is N-limited. Other soil nutrients such as phosphorus, magnesium and calcium and water availability are also higher in Spartium soils than in Cistus. Phosphorus is usually a constraint for N-fixers, but in our study, it is the most significant soil variable in both shrub formations and is important to the success of Spartium. Water availability is a key factor for Mediterranean vegetation, and particularly in autumn when soils are recharged. The Spartium formation is able to retain water as its growth produces a closer canopy than Cistus, thereby preventing water evaporation and contributing to the success of this species. Perennials are more frequent in the standing vegetation than in the seed bank, whereas therophytes are similar. The standing vegetation has therophytes and chamaephytes as the predominant growth forms in Spartium sites, and hemicryptophytes and phanerophytes in Cistus. Therophytes are dominant in Spartium and Cistus seed banks, although the first formation has more species. Spartium has a higher number of hemicryptophytes and Cistus is higher in phanerophytes. Northern and eastern aspects show significant differences in richness—with a predominance of annual weed species in Spartium —and in above-ground net primary production, probably as a consequence of the nutrients present in the soils. Ruderal annual species under Spartium (Bromus tectorum, Chenopodium album) have higher germination rates in the greenhouse than in the standing vegetation, suggesting they are at potential risk if environmental conditions change.     

Mineral and Trace Elements Content in 30 Accessions of Tomato Fruits (Solanum lycopersicum L.,) and Wild Relatives (Solanum pimpinellifolium L., Solanum cheesmaniae L. Riley, and Solanum habrochaites S. Knapp & D.M. Spooner)

Tomato quality and its potential health benefits are directly related to its chemical composition. The characterization of nutritional properties of Solanum germplasm is essential to choose suitable donor parents for breeding programs. In this sense, wild species could be very useful for tomato fruit quality genetic improvement. With this objective, in this work, we characterize micronutrients content in Eulycopersicon germplasm (20 cultivars of S. lycopersicum L. and 10 accessions of wild relatives) analyzing mineral (Na, K, Ca, Mg) and trace elements (Cu, Fe, Zn, Mn) and applying multidimensional analysis (principal component and cluster analysis). The classification obtained and the comparison of cultivars performance showed that wild accessions belonging to S. cheesmaniae (L. Riley), S. pimpinellifolium L., and S. habrochaites S. Knapp & D.M. Spooner can be of great usefulness in breeding programs to improve mineral content characteristics of conventional S. lycopersicum varieties due to its higher mineral content.     

Mediterranean hay meadow communities: diversity and dynamics in mountain areas throughout the Iberian Central Range (Spain)

This paper reports a phytosociological study on managed hay meadow communities in the main mountains of the Spanish Central Range. Multivariate techniques (Cluster analysis and CA-ordination) were applied in the classification of the relevés and ordination of vegetation units and species. Clusters were related to the following associations: Agrostio castellanae–Arrhenatheretum bulbosi, Festuco amplae–Cynosuretum cristati, and F. amplae–Agrostietum castellanae. The scattergram suggested that the dynamic patterns between communities are associated with soil nutrient content and moisture. We propose a new subassociation: F. amplae–A. castellanae gaudinietosum fragilis that includes Salmantincensean Agrostis castellana communities growing in regions with lower supramediterranean thermotype.     

Another example of cryptic diversity in lichen-forming fungi: the new species <Emphasis Type="Italic">Parmelia mayi</Emphasis> (Ascomycota: Parmeliaceae)

In the last decade, a number of cryptic species have been discovered in lichenized fungi, especially in species with a cosmopolitan or disjunctive distribution. Parmelia saxatilis is one of the most common and widely distributed species. Recent molecular studies have detected two species, P. ernstiae and P. serrana, within P. saxatilis s. lat., suggesting the existence of considerable genetic diversity that may not yet be expressed at the phenotypic level. Due to the complexity in the P. saxatilis s. lat. group, we used this as a model to study the species boundary and identify cryptic lineages. We used Phylogenetic (Bayes, ML and MP) and genetic distance approaches to analyze ITS and β-tubulin sequences. Our results confirm the existence of another cryptic lineage within P. saxatilis s. lat. This lineage is described herein as a new species, P. mayi. It forms an independent, strongly supported, monophyletic lineage, distantly related to the morphologically similar species P. ernstiae, P. saxatilis and P. serrana. Morphologically, it is indistinguishable from P. saxatilis but the new species is separated by molecular, bioclimatic, biogeographic and chemical characters. At present, P. mayi appears to have a restricted distribution in the northern Appalachian mountain territories of North America. It is found in climatic conditions ranging from hemiboreal and orotemperate to cryorotemperate ultrahyperhumid bioclimates.     

Nickel localization in tissues of different hyperaccumulator species of Euphorbiaceae from ultramafic areas of Cuba

Pantropical species of the genera Phyllanthus and Euphorbia and the Cuban endemic genus Leucocroton from the Euphorbiaceae family, were selected for nickel localization microanalysis. Scanning Electron Microscopy coupled with Energy Dispersive X-ray Microanalysis (SEM-EDX) was used for qualitative detection of nickel in the selected Ni-hyperaccumulator species: Euphorbia helenae, Leucocroton linearifolius, L. flavicans Phyllanthus orbicularis, P. discolor and P. xpallidus, all collected from Cuban ultramafic soils. The leaves and stems from the Euphorbiaceae species analyzed were the organs with higher nickel accumulation. Elemental mapping of leaves and stem tissues from these species have been compared. The highest Ni concentrations were found in the laticifer tubes of stems and the epidermis tissues of leaves in all the analyzed species, suggesting a general pattern of the Euphorbiaceae family for nickel accumulation. The high nickel concentrations and its rather homogeneous distribution found in leaves of these Ni-hyperaccumulating plants suggest a possible role in protection mechanisms against environmental stress, such as UV irradiation.     

A study of Sarcocornia A.J. Scott (Chenopodiaceae) from Western Mediterranean Europe

The latest publications on Sarcocornia taxonomy and phylogeny recognize six taxa in this genus on the Iberian Peninsula: S. perennis, S. fruticosa, S. alpini, S. alpini subsp. carinata, S. hispanica, and S. pruinosa. The present study represents a comprehensive revision of the different taxa in the Sarcocornia genus present in Western Mediterranean Europe by means of morphological, micromorphological and phylogenetic internal transcribed spacer (ITS) analysis. Morphological and micromorphological data were studied from Sarcocornia samples from 113 populations in coastal salt marshes and inland salt pans in Portugal, France, Spain and Italy. Sixteen new ITS sequences were obtained from Mediterranean Sarcocornia species and analysed together with previous reported data. Published karyological, ecological and biogeographical data from Western Mediterranean Europe were also reviewed. The results indicate the presence of a new species, S. lagascae, found growing in coastal Mediterranean areas of the Iberian Peninsula. The species S. fruticosa was found to be absent from the Iberian territories.