scholarly journals Molluscan and sedimentological sequences of the late Quaternary deposits of Morsott region (NE Algeria) and their paleoenvironmental implication

2018 ◽  
Vol 189 (4-6) ◽  
pp. 17
Author(s):  
Smaine Chellat ◽  
Lotfi Toubal ◽  
Abderrezak Djerrab ◽  
Ahcene Bourefis ◽  
Belhadj Hamdi-Aissa ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Climatic Changes ◽  
Quaternary Deposits ◽  
Quaternary Sequences ◽  
Fluvial Dynamics ◽  
North Eastern ◽  
Molluscan Fauna ◽  
Eastern Algeria ◽  
Insight Into ◽  
Semi Arid

The late Quaternary sequences of north-eastern Algeria composed of alternating dark and light layers, which are rich in molluscan fauna, could correspond to synchronous environmental phases. The facies variations of the Morsott Region deposits were systematically sampled as part of a sedimentological and malacological study in order to establish a palaeoenvironmental and climatic reconstruction of the late Quaternary. The alternation of sandy clayey silts levels, which contain abundant molluscan hygrophilous organisms, indicates an isostasis cycle followed, at the top, by a succession of rhexistasis and biostasis cycles. The molluscan record shows a dominant succession of xerophilous organisms in relation to the hygrophilous organisms. The faunistic richness in the fine levels is linked to sub-humid periods where the region has suffered numerous floods. The reduction in the number of species in the coarse levels comes is likely due to desiccation when the climate was semi-arid. This study is new in Algeria and will provide an insight into climatic changes. Further research will be required in order to understand the fluvial dynamics during the Quaternary.

Responses of Non-volant Mammals to Late Quaternary Climatic Changes in the Wet Tropics Region of North-eastern Australia

1997 ◽  
Vol 24 (5) ◽  
pp. 493 ◽  
Author(s):  
J. W. Winter
Keyword(s):  
Late Quaternary ◽  
Temperature Tolerance ◽  
Climatic Changes ◽  
Glacial Period ◽  
Profound Influence ◽  
Eastern Australia ◽  
North Eastern ◽  
Sclerophyll Forest ◽  
Wet Tropics ◽  
Glacial Periods

It is generally recognised that the distribution of vertebrates in rainforest and wet sclerophyll forest of the Wet Tropics region of north-eastern Australia is profoundly influenced by the formation of two rainforest refugia at the height of Pleistocene glacial periods. Anomalies in the distribution of non-volant mammals indicate that other events may be equally important. In this paper, past geographical occurrence of non-volant mammals is examined by equating the mammals’ known temperature tolerance with palaeoclimatic temperature zones. It is hypothesised that dispersal and vicariant phases taking place since the most recent glacial period have had a profound influence on current patterns of distribution. A major dispersal phase of cool-adapted species occurred after the glacial period, and continuous populations were subsequently fragmented into upland isolates by expansion of warm rainforest during the late post-glacial period. These upland isolates remain substantially unchanged to the present day. Species shared either with New Guinea or south-eastern Australia arrived in the region during the most recent post-glacial period. Clarification of periods of vicariance and dispersal provides a conceptual framework for testing relative divergences of populations within and between regions.

scholarly journals Groundwater Quality in Two Semi-Arid Areas of Algeria: Impact of Water Pollution on Biodiversity

2020 ◽  
Vol 7 (3) ◽  
pp. 16-34 ◽  
Author(s):  
Redjaimia Lylia ◽  
Hadjab Ramzi ◽  
Khammar Hichem ◽  
Merzoug Djemoi ◽  
Saheb Menouar
Keyword(s):  
Hot Springs ◽  
Well Water ◽  
Dumping Site ◽  
North Eastern ◽  
Eastern Algeria ◽  
The City ◽  
Subterranean Waters ◽  
Semi Arid ◽  
Subterranean Water

The biodiversity and quality of subterranean waters were comparatively studied in the Tarf plain near Oum-El-Bouaghi and in the Ksar S’bahi in Oum-El-Bouaghi, in North-eastern Algeria. For this purpose, physicochemical and faunistic analyses were carried out on the water of ten stations located in the area of Tarf, and thirteen in the area of S’bahi. In the wells of Tarf, the average stygobiologic diversity was relatively high in the wells located upstream the dumping site from the city where the groundwater presented low contents of nitrates and orthophosphates. In contrast, the wells located in the spreading zone of Tarf wastewaters were characterized by the scarcity or the absence of stygobic species; in these latter wells, the water was highly polluted. It was rich in nitrates, nitrites, ammonium, and the conductivity was rather high. In the area of S’bahi, the faunistic inventory recorded ten species, some of which were living in hot springs. The subterranean water was highly mineralized. In the two studied areas, biodiversity decreased when well water was locally polluted.

scholarly journals Analysis of trend rainfall: Case of North-Eastern Algeria

2018 ◽  
Vol 36 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Dounia Mrad ◽  
Yassine Djebbar ◽  
Yahia Hammar
Keyword(s):  
Arid Regions ◽  
Winter Season ◽  
Magnitude Estimate ◽  
Annual Rainfall ◽  
Distance Weighting ◽  
North Eastern ◽  
Eastern Algeria ◽  
Annual Scale ◽  
Inverse Distance ◽  
Semi Arid

AbstractThe climatic change is a reality largely recognized today in the scientific community. Nevertheless, its impact on precipitation, especially on annual, monthly and seasonally rainfall in arid and semi-arid regions is not yet certain. Indeed, very few studies have dealt with this matter in Algeria.In this context to examine spatial distribution of annual and seasonal rainfall an attempt has been made using the inverse distance weighting (IDW) method. Trends and magnitude estimate of change in rainfall series were detected by Mann–Kendall tests and Sen's test slope, has been applied to the data registered of 35 stations in the watershed Constantinois Seybouse Mellegue (CSM) North-Eastern Algeria over a period of 43 years (1969–2012).Results from spatial plot of annual rainfall showed that the rainfall increases with altitude, but is higher for the stations exposed to moist winds. It also increases from east to west and conversely decreases as one moves away from the coast to the south. From statistical method showed that there are increase trends at 95% confidence at annual scale in some rainfall stations with high altitude and coastal stations during winter season.

scholarly journals Effect of supplemental irrigation on bread wheat genotypes yield under Mediterranean semi-arid conditions of north-eastern Algeria

2021 ◽  
Vol 74 (1) ◽  
Author(s):  
Mohamed Ridha Aissaoui ◽  
Mohamed Fenni
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Triticum Aestivum L ◽  
Supplemental Irrigation ◽  
Arid Conditions ◽  
North Eastern ◽  
Rainfed Conditions ◽  
Eastern Algeria ◽  
Jointing Stage ◽  
Semi Arid

 Different levels of supplemental irrigation regimes on four wheat (Triticum aestivum L.) genotypes were evaluated, two of which were introduced into Sétif region by ACSAD institution, during the growing season 2013-2014, in order to assess the effect of deficit irrigation pattern on yield traits performance and to determine most suitable genotype for local semi-arid conditions. On the basis of the experimentation data, it was found that supplemental irrigation improved the investigated genotypes yield, which ranged from 220.03 g m-2 for variety El-wifak in rainfed conditions to 368.3 g m-2 for variety Djanet (ACSAD899) with an increase of about 67%; just by applying two irrigations, the first at the jointing stage and the second at mid-flowering stage. This increase was related to the improvement of most agronomic traits that correlated significantly and positively with grain yield, in response to supplemental irrigation application. These findings indicated that Djanet (ACSAD899) was a genotype successfully introduced under irrigated conditions, while Hidhab (HD1220) with an average grain yield of 298.3 g m-2, proved to be more stable and well adapted to the locally rainfed conditions.

scholarly journals Impact of Anthropic Pressure on the Quality and Diversity of Groundwater in the Region of Sighus Oum-El-Bouaghi and El Rahmounia, Algeria.

2020 ◽  
Vol 7 (3) ◽  
pp. 85-105
Author(s):  
HADJAB RAMZI ◽  
KHAMMAR HICHEM ◽  
REDJAIMIA LYLIA ◽  
MERZOUG DJEMOI ◽  
SAHEB MENOUAR
Keyword(s):  
Water Quality ◽  
Human Activity ◽  
Arid Regions ◽  
The Other ◽  
Aquatic Fauna ◽  
North Eastern ◽  
Eastern Algeria ◽  
The Relationship ◽  
Semi Arid ◽  
Anthropic Pressure

Groundwater of Oum-El-Bouaghi and its surroundings hosts a variety of microflora and fauna. This study investigated the relationship between the effect of human activity and the biodiversity and distribution of aquatic fauna in two semi-arid regions Sighus region (Oum-El-Bouaghi) and El Rahmouni (Constantine) in north-eastern Algeria. Fourteen wells and six springs were studied in two hydrographic basins, that of Constantine and Seybouse Melegue. Significant differences were revealed between the wells and springs in the two watersheds, making it possible to distinguish four groups of wells and two groups of springs. The overall faunal richness of the stations appeared to be weakly correlated with water quality, but on the other hand, the specific richness of the stygoby fauna, and even more so the abundance of stygoby species, decreased when water quality deteriorated.

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