99 research outputs found
Distribution and ecology of the superior mushrooms of the Aulnaie of Ain Khiar (El Kala National Park, Northeastern Algeria)
The macro-ecology of the superior mushrooms in the peat land of the El Kala National Park (Algeria) is totally unknown. The research presented here aims at determining the environmental factors which might explain the distribution of mushrooms and contribute to the knowledge of the mycofloristic composition of this particular environment. For that purpose, we selected a protected site in the El Kala National Park, classified RAMSAR since 2002 as: “the Peat land of Ain Khiar". The carpophores of mushrooms were exhaustively recorded on a monthly basis from November, 2003 until May 2008, and several environmental factors which might determine the distribution of the species such as altitude, acidity of the ground, the degree of humidification of peat land, floral composition of the vegetation were also recorded. The site of Ain Khiar is part of 60 sites studied at the El Kala National Park, which will be the subject of future other publications. Twenty two species were collected on the site, among which 6 species (25 %) were found to be unique to this site. A differentiated analysis according to functional groups of macrofungi showed that the 15 saprotrophs species are determined by several factors of comparable importance; while the ectomicorrhizal are mainly determined by the most dominant species. A more relevant analysis of the ecology of the fungal communities is thus obtained by distinguishing the functional groups, their specific composition being determined by different environmental factors.Key words: Macrofungi, inventory, Peat Land of Ain Khiar, trophic status, distribution
A survey of the hoverflies of northeastern Algeria (Diptera: Syrphidae)
A survey of the hoverfly fauna of northeastern Algeria was carried out in 1991 and 1992, and seventy-three species recorded. Four species are new for Algeria: Dasysyrphus albostriatus, Chamaesyrphus lusitanicus, Brachypalpus laphriformis and Spilomyia maroccana. The genera Dasysyrphus, Chamaesyrphus and Brachypalpus are new for Algeria. Data on the distribution and the seasonal pattern of each species are provided. Species richness was found highest amongst wetlands (up to 38) and forested hills (up to 29). In contrast, degraded sites held the lowest numbers of hoverflies. Species such as Episyrphus balteatus, Sphaerophoria scripta, Syritta pipiens and Eristalis tenax were widespread and abundant, whereas others were rare (Platycheirus albimanus) or confined to forested hills, such as the North African endemic Volucella liquida. A good knowledge of the Syrphidae will pave the way to a close monitoring of global changes affecting the region and the conservation of an important but much neglected group in one of the foremost biodiversity hotspots of the Maghreb.Keywords: Syrphids, distribution, biodiversity, conservation, Algeria
Chironomid taxocenosis in a South Mediterranean wadi, the Kebir-East (Algeria)
SUMMARY - Chironomid taxocenosis in a South Mediterranean wadi, the Kebir-East (Algeria) - A total of 37 chironomid species were
recorded during a survey of the catchment of the Kebir-East wadi, northeast Algeria. Chironomids spatial and temporal distributions were
investigated based on 23 sampling sites, situated mainly within the El Kala National Park, across 4 seasons. Chironomid assemblages in
the Kebir-East were similar to the ones known from other Mediterranean areas and were composed mostly of tolerant species (Chironomus
riparius, Cricotopus (Isocladius) sylvestris), but some intolerant species (Paratrissocladius excerptus, Parakiefferiella gracillima, Thienemanniella
partita) were present in some samples. A coinertia analysis was carried out to match 21 environmental variables at different
spatial scales with the 37 chironomid species recorded in 90 samples: A longitudinal gradient was found along the first axis, which accounted
for 42 % of the total variance; the samples ordered along the second axis, which accounted for 13 % of the total variance, were
separated according to water temperature, water chemistry and site\u2019s morphometry. The influence of anthropogenic pressures was evaluated
with different benthic quality indices based on species diversity and on species optima (i.e. mean value of environmental variables
weighted for species abundance). Results showed that the trophic status index was influenced by water quality and habitat type (krenal,
rhithral, potamal), while the biotic indices were more influenced by season. To improve knowledge on the response of intolerant species,
we suggest the implementation of a regular, more intensive sampling program
Two new species of Centroptilum Eaton, 1869 from North Africa (Ephemeroptera, Baetidae).
Based on recently collected larvae from Algeria and Morocco, the species delimitation within the genus Centroptilum Eaton, 1869 in that region is validated. Two new species are described and illustrated, one from north-eastern Algeria, and one from North Morocco, using an integrated approach with morphological and molecular evidence. A table summarising the morphological differences between the new species and Centroptilumluteolum (Müller, 1776) from Central Europe is provided. Further, molecular evidence for additional undescribed species of Centroptilum in other regions of the West Palearctic is provided and discussed
Environmental factors affecting the distribution of Chironomid larvae of the Seybouse wadi, Northeastern Algeria
A survey of the Seybouse wadi (North-Eastern Algeria) between 2008 and 2011 was conducted in 26 sampling sites located on the main river and its tributaries using chironomids. From 3264 collected larvae, forty-five chironomid species were identified, and were correlated to 13 environmental variables to predict determinant factors affecting their distribution. Indicator value (IndVal) analysis was first performed to determine indicator chironomid species according to several factors (sites, seasons, source distance, granulometry, conductivity, water temperature, dissolved oxygen, water velocity, pollution and the abundance of filamentous algae). Co-inertia analysis
(CoIA) supported the IndVal results, emphasising an upstream/downstream gradient in the first axis, while a granulometry gradient was emphasised by the second axis. A pollution gradient was also highlighted in the plane of the first two axes, separating tolerant Chironomus sp. 1, Cricotopus bicinctus and Cricotopus (Isocladius) sylvestris from intolerant species as Phaenopsectra flavipes, Rheotanytarsus sp.1 and Cladotanytarsus sp. 1
The future for Mediterranean wetlands: 50 key issues and 50 important conservation research questions
Wetlands are critically important for biodiversity and human wellbeing, but face a range of challenges. This is especially true in the Mediterranean region, where wetlands support endemic and threatened species and remain integral to human societies, but have been severely degraded in recent decades. Here, in order to raise awareness of future challenges and opportunities for Mediterranean wetlands, and to inform proactive research and management, we identified (a) 50 key issues that might affect Mediterranean wetlands between 2020 and 2050, and (b) 50 important research questions that, if answered, would have the greatest impact on the conservation of Mediterranean wetlands between 2020 and 2050. We gathered ideas through an online survey and review of recent literature. A diverse assessment panel prioritised ideas through an iterative, anonymised, Delphi-like process of scoring, voting and discussion. The prioritised issues included some that are already well known but likely to have a large impact on Mediterranean wetlands in the next 30 years (e.g. the accumulation of dams and reservoirs, plastic pollution and weak governance), and some that are currently overlooked in the context of Mediterranean wetlands (e.g. increasing desalination capacity and development of antimicrobial resistance). Questions largely focused on how best to carry out conservation interventions, or understanding the impacts of threats to inform conservation decision-making. This analysis will support research, policy and practice related to environmental conservation and sustainable development in the Mediterranean, and provides a model for similar analyses elsewhere in the world
Distribution of the Iberian Calopteryx Damselflies and Its Relation with Bioclimatic Belts: Evolutionary and Biogeographic Implications
Using bioclimatic belts as habitat and distribution predictors, the present study examines the implications of the potential distributions of the three Iberian damselflies, Calopteryx Leach (Odonata: Calopterygidae), with the aim of investigating the possible consequences in specific interactions among the species from a sexual selection perspective and of discussing biogeographical patterns. To obtain the known distributions, the literature on this genus was reviewed, relating the resulting distributions to bioclimatic belts. Specific patterns related to bioclimatic belts were clearly observed in the Mediterranean region. The potential distribution maps and relative frequencies might involve latitudinal differences in relative abundances, C. virgo meridionalis Sélys being the most abundant species in the Eurosiberian region, C. xanthostoma (Charpentier) in the northern half of the Mediterranean region and C. haemorrhoidalis (Vander Linden) in the rest of this region. These differences might explain some previously described latitudinal differences in secondary sexual traits in the three species. Changes in relative abundances may modulate interactions among these species in terms of sexual selection and may produce sexual character displacement in this genus. C. virgo meridionalis distribution and ecological requirements explain its paleobiogeography as a species which took refuge in Iberia during the Würm glaciation. Finally, possible consequences in species distributions and interactions are discussed within a global climate change context
Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic Islands
The deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [401045/2014-5]Spanish Ministry of Education, Culture and Sport [FPU014/06783]info:eu-repo/semantics/publishedVersio
"Nested" cryptic diversity in a widespread marine ecosystem engineer: a challenge for detecting biological invasions
<p>Abstract</p> <p>Background</p> <p>Ecosystem engineers facilitate habitat formation and enhance biodiversity, but when they become invasive, they present a critical threat to native communities because they can drastically alter the receiving habitat. Management of such species thus needs to be a priority, but the poorly resolved taxonomy of many ecosystem engineers represents a major obstacle to correctly identifying them as being either native or introduced. We address this dilemma by studying the sea squirt <it>Pyura stolonifera</it>, an important ecosystem engineer that dominates coastal communities particularly in the southern hemisphere. Using DNA sequence data from four independently evolving loci, we aimed to determine levels of cryptic diversity, the invasive or native status of each regional population, and the most appropriate sampling design for identifying the geographic ranges of each evolutionary unit.</p> <p>Results</p> <p>Extensive sampling in Africa, Australasia and South America revealed the existence of "nested" levels of cryptic diversity, in which at least five distinct species can be further subdivided into smaller-scale genetic lineages. The ranges of several evolutionary units are limited by well-documented biogeographic disjunctions. Evidence for both cryptic native diversity and the existence of invasive populations allows us to considerably refine our view of the native versus introduced status of the evolutionary units within <it>Pyura stolonifera </it>in the different coastal communities they dominate.</p> <p>Conclusions</p> <p>This study illustrates the degree of taxonomic complexity that can exist within widespread species for which there is little taxonomic expertise, and it highlights the challenges involved in distinguishing between indigenous and introduced populations. The fact that multiple genetic lineages can be native to a single geographic region indicates that it is imperative to obtain samples from as many different habitat types and biotic zones as possible when attempting to identify the source region of a putative invader. "Nested" cryptic diversity, and the difficulties in correctly identifying invasive species that arise from it, represent a major challenge for managing biodiversity.</p
Factors affecting nesting success in the Great-crested Grebe Podiceps cristatus at Lake Tonga, north-east Algeria
The breeding ecology of the Great-crested Grebe Podiceps cristatus was investigated over four consecutive years (2009–2012) at Lake Tonga, north-east Algeria. In all four years, the egg-laying period was relatively short, spanning two months (end of March to end of May), and bimodal. Nests were mainly located in Phragmites australis, over water of substantial depth (178 ± 43 cm, N = 209), far from the shore and in habitat with low vegetation cover (12.37 ± 7.67%, N = 209). The overall clutch size was 3.73 ± 0.92 eggs (N = 127) and it decreased marginally over time. The overall nesting success was 70.4% (N = 209), with nest failure caused mainly by predation (65%) and flooding (23%). Breeding outcome was significantly and positively related to nest size, with bigger nests conferring better survival to eggs and young probably through affording better protection during spells of adverse weather. However, the benefits of bigger nests may be confounded by the age or intrinsic quality of birds. The location of nests in P. australis, rather than other vegetation types, increased nesting success marginally but significantly. Two cases of interspecific mixed clutches involving the Great-crested Grebe were recorded.Keywords: breeding, mixed clutches, nest-site selection, nest size, North Africa, Podiceps cristatus, waterbird
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