Search results for "Biogeography"

The Mediterranean region - a hotspot for plant biogeographic research.

2004

Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae).

2003

To explore the biogeographic history of Mediterranean/arid plant disjunctions, Old and New World Senecio sect. Senecio were analyzed phylogenetically using nuclear ribosomal DNA sequences (ITS). A clade corresponding to sect. Senecio was strongly supported. Area optimization indicated this clade to be of southern African origin. The Mediterranean and southern African floras were not distinguishable as sources of the main New World lineage, estimated to have become established during the middle Pliocene. Another previously suspected recent dispersal to the New World from the Mediterranean was confirmed for the recently recognized disjunction in S. mohavensis. The loss of suitable land connec…

The marine Crustacea Decapoda of Sicily (central Mediterranean Sea): A checklist with remarks on their distribution

2003

A checklist of the Crustacea Decapoda of Sicily, based on pre­ viously published records and on original data, is presented. The Sicilian waters were divided into three sectors to account for the different habitats present along the northern and western (sector A), eastern (B) and southern (C) coasts, for the sake of a better interpretation of the species distribution. A total of 186 species was recorded between 0 and 800 m depth, 31 of which are re­ ported here for the first time. Sector A hosted 153 species, B 105 species, and C 117 species. The dissimilarities among the habitats present in the shallow waters of the three sectors accounted for the low co-occurrence of species: 30 species …

Mediterranean island biogeography: Analysis of fern species distribution in the system of islets around Sicily

2011

The aim of this article was to test the way in which geographical factors influence island floras in the Mediterranean basin, using ferns as target organisms, and the islands surrounding Sicily as location. A matrix with presence/absence data concerning fern taxa in the 16 islands studied was compiled. Cluster analysis, principal co-ordinates analysis (PCoA), principal components analysis (PCA) and a Bayesian analysis were performed. For each island, the total number of fern taxa was regressed against three factors: island area, island elevation and isolation. All the analyses pointed to affinities between islands according to their different geological composition, independently from their…

Pseudolillia Maubeuge, 1949 (Ammonitida, Hildoceratidae) in the Lower Jurassic (Toarcian) of the NE Spain

2017

In the present paper, 147 specimens assigned to the genus Pseudolillia Maubeuge, 1949 are studied. This is a considerably high number of samples in comparison with those known in other geographical areas where they have been cited, such as northern France, the Pyrenees, the Betic Range, Morocco, Portugal, Italy, Hungary and Bulgaria. The six taxa described, P. murvillensis, P. hispanica, P. emiliana, P. donovani, Pseudolillia ? n. sp. (en García-Gómez & Rivas, 1980), and Pseudolillia ? sp., come from 22 sites in the Cantabrian and Iberian Ranges and the Isle of Majorca. Their presence in expanded sections enabled us to situate the stratigraphic position of the genus between the upper part o…

A contribution to the phylogeny and biogeography of the genus Isoetes (Isoetaceae, Lycopodiidae) in the Mediterranean region

2019

To better understand the phylogeny of Isoetes species in the Mediterranean region, sequences of the second intron of a LFY-like homolog were determined for six populations of three Mediterranean Isoetes species and analyzed with other LFY and ITS sequences of Euro-Mediterranean species available in GenBank. Nomenclature of selected species was updated according to recent literature. Investigations of voucher specimens from previously sequenced taxa revealed that a specimen of I. histrix from Crete, Greece used in several previous molecular studies is probably I. phrygia. Analysis of the limited LFY and ITS DNA sequence data presented here agrees with the organization of Mediterranean specie…

Floristic traits and biogeographic characterization of the Gennargentu massif (Sardinia)

2013

A study on the vascular flora of the Gennargentu Massif (Central-Eastern Sardinia) is presented. According to our results, the flora consists of 948 taxa: 686 species, 249 sub- species, 10 varieties and 3 hybrids, belonging to 97 families and 427 genera. Three taxa are new findings for the flora of Italy and eight for that of Sardinia. Life form analysis revealed, in particular, dominance of 35.65 % hemicryptophytes, 34.6 % therophytes, 12.13 % geophytes and 11.6 % (nano)-phanero- phytes. As concerns chorology, the Mediterranean element is largely prevailing (68.14%), mainly represented by circum- Medit. (29.1 %) and Euro-Medit. (23.07 %). Endemics are 14.87% of the whole flora (141 taxa), …

The Diaptomidae (Copepoda, Calanoida) of Tunisia and the role of spatial and environmental factors as drivers of their distribution patterns

2023

AbstractEven in a biodiversity hotspot such as the Mediterranean basin, aspects relating to the distribution of some groups of microcrustaceans still need clarification. In this paper, we critically analyse the available information on diaptomid copepods in Tunisian inland waters and, based on the largest sampling campaign to date carried out in the country, report new data on their distribution. In the frame of this study, 248 crustacean samples were collected from 190 sites, and 10 diaptomid species belonging to 7 genera and 2 subfamilies were found in the samples. Their distribution follows a climate gradient determined by precipitation, and ecological variables mainly affect diaptomid d…

How, when and where from of the Abruzzo-Apulian palaeofauna.

2009

Perspectives on the Impact of Sampling Design and Intensity on Soil Microbial Diversity Estimates

2019

Soil bacterial communities have long been recognized as important ecosystem components, and have been the focus of many local and regional studies. However, there is a lack of data at large spatial scales, on the biodiversity of soil microorganisms; national or more extensive studies to date have typically consisted of low replication of haphazardly collected samples. This has led to large spatial gaps in soil microbial biodiversity data. Using a pre-existing dataset of bacterial community composition across a 16-km regular sampling grid in France, we show that the number of detected OTUs changes little under different sampling designs (grid, random, or representative), but increases with t…