Search results for " Biogeography."

Factors affecting between-lake variation in the occurrence of epidermal papillomatosis in roach,Rutilus rutilus(L.)

2009

The theory of island biogeography predicts that the probability of a species occupying an island depends on a dynamic equilibrium between extinction and colonization. Epidermal papillomatosis is a disease manifesting as skin tumours on fish. We studied the factors affecting the occurrence of the disease in roach, Rutilus rutilus (L.), in 34 lakes. The results of discrimination analysis suggest that maximum depth, percentage of the drainage area of the lake covered by lakes in the vicinity and altitude best identified diseased lakes. Comparison of diseased and non-diseased lakes revealed that lake area could also be regarded as a variable contributing to the occurrence of the disease. The sa…

TAXONOMY AND AFFINITIES OF AFRICAN CENOZOIC METATHERIANS

2021

The record of extinct African metatherians (Mammalia, Theria) is scanty, restricted in time (Eocene–Miocene), and its taxonomy is still subject of debate. A review of all African metatherians, or alleged metatherians, known up to now, led us to the recognition of only three taxa referable to this group: (1)  Kasserinotherium tunisiense  (Peradectoidea?), from the early Eocene of Tunisia; (2)  Peratherium africanum  (Herpetotheriidae), from the early Oligocene of Egypt and Oman, and (3) an indeterminate Herpetotheriidae? from the early Miocene of Uganda. Herpetotheriids probably reached Afro-Arabia from Europe in one or more dispersal waves since the early Oligocene.  Kasserinotherium , on t…

The use of insular vertebrates in palaeogeographic reconstructions.

2009

Species–area relationship and small-island effect of vascular plant diversity in a young volcanic archipelago

2021

International audience; Aims: Aeolian islands form an active volcanic archipelago. By using updated vascular plant checklists for islands and islets, we tested four hypotheses: (i) Island speciesarea relationship (ISAR) of alien species has lower c-and higher z-values than native species, (ii) islands with active volcanoes have lower species richness than expected for native and alien species, (iii) ISAR of native species shows lower c-and higher z-values than ISARs of Mediterranean land bridge archipelagos and (iv) species richness of smaller islets is independent of area.Location: Aeolian Archipelago, Mediterranean Basin.Taxon: Vascular plants, identified and named according to the Flora …

Blowing in the wind: how many roads can a phytoplanktont walk down? A synthesis on phytoplankton biogeography and spatial processes

2015

The selected theme of the 17th Workshop of the International Association for Phytoplankton Taxonomy and Ecology (IAP), ‘‘Biogeography and Spatial Patterns of Biodiversity of Freshwater Phytoplankton,’’ offered the opportunity to explore one neglected aspect of phytoplankton ecology: the distribution of species in the geographic space. This paper summarizes the outcomes of 20 selected contributions among those presented at the workshop. The articles report the results from studies carried out in five continents (only Oceania is not represented) and on a wide array of aquatic ecosystems (deep and shallow natural lakes, man-made lakes, temporary and permanent ponds, rivers). The topics analyze…

Sicilian Temporary Ponds: An Overview of the Composition and Affinities of their Crustacean Biota

2009

Available data on Sicilian entomostracans allowed an initial characterization of the freshwater crustacean biota of the island and to formulate some hypotheses on its origin.The absence of supra-specific endemic taxa and the current regional distriburion of the investigated species suggest a late Pleistocene colonisation of the island by temperate taxa with a northern affinity, currently confined to the coolest areas of the island, followed by a Holocene arrival of thermophilous species coming from the Maghreb, which is still in progress. The importance of Sicily as a "crossroad" for the faunas of the circum-Mediterranean countries is thus confirmed.Unfortunately, and in spite of the EU dir…

Biogeography of Tertiary Primates: Discussion over an updated Data Base

2009

A preliminary taxonomic evaluation of the Tertiary Primate fossil record of the Old World is presented. The dataset has been compiled using the information and the structure presented by the NOW database (Neogene Mammalian of the Old World; Academy of Finland, 2007), strongly updated with the additional information derived from different literature sources. A quantitative methodology for compilation and analysis of the data has been applied following the methodology described in Petruso et al. (2008). The adopted numerical treatment of data is particularly effective in synthesizing and analyzing the large amount of information contained in the data set. This analysis gives a synthetic pictu…

Land mammal colonisation of islands is a multifactorial product; a critic to the unwise use of models

2011

The colonization of islands by terrestrial mammals has been the topic of a flurry of studies. Contributions normally tend to oversimplify the subject, focusing on specific key factors which are allegedly considered the best to explain why, how and when non volant terrestrial mammals reached islands and which are used to devise models. The subjectivity in the choice of key factors understandably leads to controversy and debate. Insular faunas are the multifactorial result of complex combinations of facts, conditions and processes. Hence, the faunal assemblages of each island should be inquired individually, on a case-by-case basis. Models, by definition, are simplified representations of rea…

What is a tree in the Mediterranean Basin hotspot? A critical analysis

2019

Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-Europ…

New challenges in anostracan research: old issues, new perspectives and hot topics

2017

We present a summary of responses to our call among scientists working on Anostraca to commemorate the late Professor Graziella Mura, a pioneer of modern studies on this group of animals. Colleagues from all over the world promptly answered and contributed their works among which we selected the fourteen papers published in the Hydrobiologia Special Volume “New Challenges in anostracan research: a tribute to Graziella Mura”. Although Anostraca are widespread globally, they are among the least known taxonomic groups. Although some biogeographical data are available for some species and higher taxa, we are still far from a clear understanding of the phylogeny, ecology and biogeography of …