Search results for "rare species"
showing 9 items of 49 documents
GASTROINTESTINAL HELMINTHS OF THE DUSKY DOLPHIN, LAGENORHYNCHUS OBSCURUS (GRAY, 1828), OFF PATAGONIA, IN THE SOUTHWESTERN ATLANTIC
1999
The stomachs and intestines of 23 dusky dolphins incidentally caught in a trawl fishery off Patagonia were surveyed for helminths. All the dolphins were parasitized, with a total of 3,936 helminth individuals. Only five species occurred, of which three were common (prevalence ± 10%): Anisakis simplex, Braunina cordiformis and Hadwenius sp. A. simplex was present in all the dolphins and showed the highest abundance and mean intensity (104.9 individuals/infected host). B. cordiformis was next most common (87%), and Hadwenius sp. third (52.2%). A. simplex was found mostly in the stomach (94.8%), B. cordiformis in the duodenal ampulla (51.4%), and Hadwenius sp. in the stomach (64.5%). The rare …
A Complete Description and Conservation Assessment of Riella affinis Howe & Underwood (Riellaceae, Sphaerocarpales) New to Continental Europe
2019
Riella affinis Howe & Underwood is a rare species that is thus far known from eight populations worldwide. Only half of these were recorded in the last 50 years and none were recollected since first reported. Study of a Spanish population of R. cossoniana Trab., recorded in 2002 from Las Lomas, Malaga province, revealed that it belongs to R. affinis. The correct identity of the populations, which had not been available for study, was already suggested by reproductive and ecological characteristics of the plants mentioned in the original publication. The three main lagoons from the Las Lomas endorheic system, where the plants had been recorded, were sampled and living plants of R. affinis we…
A Revision of theniveaGroup of the Shore-Fly GenusDitrichophoraCresson (Diptera: Ephydridae)
2010
ABSTRACT Species of the nivea group (genus Ditrichophora Cresson) are revised. The group now includes four species of which one, D. gulkana (Alaska and Mongolia), is newly described. The group is now known to have a Holarctic distribution with two species, D. gulkana and D. nivea, being the first reported from the Nearctic Region. Another Asian species, D. brunnicosa, previously placed in Diclasiopa, is transferred to this group (genus Ditrichophora) and is also reported from Mongolia. To facilitate identification of these rare species, we have included diagnoses of the tribe, genus, and species group and have also provided an annotated key to Holarctic genera of the tribe Discocerinini and…
Diversity and Community Structure of Opiinae (Hymenoptera: Braconidae) in the Forest Estate of Artikutza (Spain)
2011
ABSTRACT The present work analyses the diversity of Opiinae (Hymenoptera: Braconidae) in the forest of the Artikutza Estate, within the Natural Park, Penas de Aya, in the western Pyrenees. Specimens belonging to this subfamily were collected throughout two cycles and in two different habitats: mixed forest and beech forest. A total of 105 specimens, including 20 different species, were collected. Diversity and structure analysis indicated higher diversity for the beech forest habitat, although the community is composed of a few abundant species and many rare species. A relationship between the presence of Opiinae and an increase in temperature was also ascertained.
The Status of Romanogobio uranoscopus (Agassiz, 1828) Species, in Maramureş Mountains Nature Park (Romania)
2017
Abstract The condition of aquatic habitats typically occupied by Romanogobio uranoscopus within the Maramureş Mountains Natural Park fluctuates, in the best cases, between reduced to average. Good or excellent conservation status is now absent for populations of this species in the researched area. The identified human impact types (poaching, minor riverbeds morphodynamic changes, solid and liquid natural flow changes, destruction of the riparian vegetation and bush vegetation, habitat fragmentation/isolation of population, organic and mining pollution and displaced fish that are washed away during the periodic flooding in the lotic sectors uniformized by humans) are contributing to the dim…
Bio-ecological, phytosociological and conservation aspects of relictual and disjointed populations ofSimethis mattiazzi(Vandelli) Sacc. (Xanthorrhoea…
2012
Abstract Two populations of Simethis mattiazzi (Xanthorrhoeaceae) were recently discovered in the Channel of Sicily – (1) Punta Bassana (Marettimo Island) and (2) Mount S. Giuliano (western Sicily) – at a considerable distance from the nearest stations hitherto known, located in southern Sardinia, the Pontine Islands Archipelago and Tunisia. The taxonomical and distributive aspects of this species are analysed to highlight the relictual and biogeographical significance of the disjointed and fragmentary nuclei distributed in several small islands of the Channel of Sicily, the Italian Peninsula and North Africa. Some morphological, biological, ecological and phytosociological aspects of the t…
Changes in alpine snowbed-wetland vegetation over three decades in northern Norway
2013
We have quantified floristic changes in alpine snowbeds and wetland vegetation during three decades and analyzed to what extent these changes are related to initial variations in snow cover duration and distance to groundwater level. Vascular plant species richness and total plant cover were estimated along three transects in northern Norway. Three different vegetation zones were identified along the original transects: relatively dry snowbeds, wet snowbeds and wetlands. The resampling shows major changes in species richness and plant cover. In general, there was a net immigration of species and 13 new species were found. Five rare species with initial low cover were lost. In the dry and we…
The role of competition and rarity in the restoration of a dry grassland in Finland
2001
Semi-natural grasslands have become scarce throughout Europe. Preservation of their plant species requires either the maintenance of the existing grasslands or the creation of new ones. To study the establishment and regeneration ability of plant species typical of dry grasslands we laid out an experiment on a former arable field in central Finland. We compared the success of 13 grassland species both in a theoretical situation with minimal competition and in competition with weeds. More than half of the species used were regionally rare. As a group, grassland plants reached the highest cover in the experimental plots in which outside competition was minimised by weeding. However, the total…
Natural assets in the right-of-way of A-4 Motorway in the Góra Świętej Anny Landscape Park, Opole Region
2014
Construction of the A-4 Motorway section in the Opole Region begun in Summer 1997. Very soon vigorous resistance of ecological NGOs was encountered. The bone of contention was the section of motorway that passes through the Góra Świętej Anny Landscape Park and verges the natural reserve of strict protection Ligota Dolna where rare species of thermophilic plants are sheltered. Between 2011 and 2013 a detailed mycological, geobotanical, floristic and fauna research took place within the right-of-way of the A-4 Motorway section crossing the Góra Świętej Anny Landscape Park in the Opole Region. The survey revealed several rare and protected species of fungi, plants and animals along the road, i…