Papers by Abdelfattah Zalat
2022
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18 19 In the densely forested Warmia and Masuria region (north-eastern Poland) there are many 20 ... more 18 19 In the densely forested Warmia and Masuria region (north-eastern Poland) there are many 20 endorreic lakes characterized by small size, and calm slow sedimentation and lack of tributaries, 21 which makes them very good Holocene environmental and paleoclimatic archives. a very good 22 archive of environmental and paleoclimatic data for the Holocene. For this reason., Oone of them 23 the Młynek Lake Młynek, located near the village of Janiki Wielkie, has been selected for multi24 faceted palaeoenvironmental research based on a precise radiocarbon scale. Bottom Ssediments of 25 this reservoir lake also contain unique information about anthropopressionhuman impact of the 26 environementenvironment, because a defensive settlement stronghold (?)has been operating on its 27 northern shore since the early Iron Age to early Medieval period, which gives opportunity to 28 correlate paleoenvironmental data with phases of the human activity in the last 2400 years. 29 Between 3rd – 2nd cent...
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Quaternary Research, 2021
The modern Nile delta developed in the Middle and Late Holocene, and at its most northern-central... more The modern Nile delta developed in the Middle and Late Holocene, and at its most northern-central point is situated at the Burullus Lagoon, which is environmentally diverse, including salt marshes, mudflats, and sand plains, and separated from a sea by a sand barrier overtopped with high sand dunes. The lagoon has been fed since the Middle Holocene by the Sebennitic branch of the Nile and marine intrusions through the Bughaz inlet. A sediment core (BO-1) was collected at the northeastern shore of the lagoon and sampled at centennial scale resolution in order to reconstruct the development of the lagoon. The results show that an initial and limited lagoon had developed at the end of the Early Holocene, but after a dry period ca. 7.2 cal ka BP it has been progressively transformed into a marshy area, with occasional inflows of sea water. Lower water level and higher salinity of the Burullus Lagoon at 6.0–5.5 and 4.8–4.2 cal ka BP reflected droughts in the Nile catchment. Thereafter, t...
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Climate of The Past, 2021
Abstract. In the densely forested Warmia and Masuria region (northern Poland) there are many smal... more Abstract. In the densely forested Warmia and Masuria region (northern Poland) there are many small endorheic lakes characterized by their low sedimentation rate, which makes them excellent archives of Holocene environmental and palaeoclimatic change. Lake Mlynek, located near the village of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental research supported with radiocarbon dates. Sediments from this lake also contain unique information about human impact on the environment, because a stronghold has been operating on its northern shore since the early Iron Age to the early Medieval period, giving the opportunity to correlate palaeoenvironmental data with the phases of human activity over the last 2400 years. During the second and third centuries BCE the lake was surrounded by a dense deciduous forest. From the first century BCE to second century CE the forest around the lake was much reduced, which can be associated with the first pre-Roman (La Tene) and Roman occu...
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Palaeogeography, Palaeoclimatology, Palaeoecology, 2019
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Studia Quaternaria, 2016
The Lake Qarun (Faiyum Oasis, northern Egypt) is a relic of the much larger Holocene lake. Past l... more The Lake Qarun (Faiyum Oasis, northern Egypt) is a relic of the much larger Holocene lake. Past lake levels and extensions were reconstructed, based on setting of archaeological sites scattered along northern paleoshores of the ancient lake. However, geoarcheological works did not yield enough data to establish continuous environmental history of the lake. A deep drilling FA-1 on the southeastern shore of the lake, performed in 2014, supplied with a core, 26 m long that is the one of the longest lake sediment cores in northeastern Africa. The basal section of the core consisted of thin-laminated diatom marly deposits, underlain at the Late Pleistocene/Holocene boundary by coarse-grained sands. The sediment lamine were quite well developed, especially in the lower part of the core. Preliminary results indicated annually deposited sediment sequence with seasonality signals provided by microlamine of diatoms, calcite, organic matter and clastic material. Early Holocene varved sediments...
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Studia Quaternaria, 2017
This study evaluates changes in the environmental and climatic conditions in the Faiyum Oasis dur... more This study evaluates changes in the environmental and climatic conditions in the Faiyum Oasis during the Holocene based on diatom analyses of the sediment FA-1 core from the southern seashore of the Qarun Lake. The studied FA-1 core was 26 m long and covered the time span ca. 9.000 cal. yrs BP. Diatom taxa were abundant and moderately to well-preserved throughout the core sediments. Planktonic taxa were most abundant than the benthic and epiphytic forms, which were very rare and sparsely distributed. The most dominant planktonic genera were Aulacoseira and Stephanodiscus followed by frequently distribution of Cyclostephanos and Cyclotella species. The stratigraphic distribution patterns of the recorded diatoms through the Holocene sediments explained five ecological diatom groups. These groups represent distinctive environmental conditions, which were mainly related to climatic changes through the early and middle Holocene, in addition to anthropogenic activity during the late Holoc...
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Boreas, 2017
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Journal of Paleolimnology, 2005
Page 1. -1 Distribution of diatom assemblages and their relationship to environmental variables i... more Page 1. -1 Distribution of diatom assemblages and their relationship to environmental variables in the surface sediments of three northern Egyptian lakes Abdelfattah Zalat1,* and Simone Servant Vildary2 1Geology Department ...
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Journal of Paleolimnology, 2006
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A sediment core, 350 cm long recovered from Młynek Lake, northern of Poland (Warmia and Masuria R... more A sediment core, 350 cm long recovered from Młynek Lake, northern of Poland (Warmia and Masuria Region) was analyzed with respect to their content of diatoms and chrysophyte cysts. The aim was to reconstruct the lake water level and climatic changes during the past 2500 years. The recognized diatom assemblages displayed marked floristic changes along the sediment core samples. The main change in diatom composition consists of a shift from an assemblage dominated by benthic Fragilaria sensu lato species through marked intervals to a planktonic one in distinct zones. A high proportion of benthic to plankton taxa has been reported as indicative for a lowering of the lake level with long ice cover in a cold dry climate and a shift from benthic to planktonic diatom taxa reflects arising water level with longest growing season and reduced ice cover on the lake during a warm wet climate. Multivariate statistical analysis included hierarchical ascending clustering distinguished four diatom ...
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John Paul II University of Applied Sciences in Biala Podlaska, 2022
High-resolution diatom investigation from the Polish ecosystem is presented as a contribution to ... more High-resolution diatom investigation from the Polish ecosystem is presented as a contribution to our knowledge
of diatom floristics, ecology, biogeography, and their significance in environmental and climate reconstruction
in Poland. The study is based on the analysis of 821 sediment samples taken from different lakes in northern
Poland, besides 8 borehole-originated from the Eemian paleolakes sites in central Poland. The preceding diatom
results in published papers included the diatom flora that were recorded from different habitats in Poland are
mentioned in the present work to complete the Polish diatoms list. The current work is the first part in a series
of monographs dealing with the diatom taxa belonging to classes Coscinodiscophyceae, Mediophyceae and subclass
Fragilariophycidae. A total of 269 diatom species and varieties belonging to 38 genera are recognized. The
checklist is comprising 86 entries of Coscinodiscophyceae that includes all radial centric diatoms and 183 taxa of
Fragilariophyceae that includes araphid pennate diatoms. Of these 97 diatom taxa are represented as a new record
for Poland and 12 new combinations and new varieties. A detailed diatom description, distribution in Poland, and
autecological information are presented to round up the content of this volume and documented with 120 plates
including 2423 excellent light micrographs of diatom taxa, which allows for a better understanding of morphology
to aid in the identification. This work is proposed to contribute towards a general view of the high diatom biodiversity
that characterizes Polish ecosystems and provides a revised diatom checklist from Poland. Additionally, it
offers the first taxonomic and autecological catalog, which will be significant in the assessment of the water quality
monitoring, paleoenvironmental interpretation, and construct the paleoclimate changes.
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Quaternary Research, 2022
The modern Nile delta developed in the Middle and Late Holocene, and at its most northern-central... more The modern Nile delta developed in the Middle and Late Holocene, and at its most northern-central point is situated at the Burullus Lagoon, which is environmentally diverse, including salt marshes, mudflats, and sand plains, and separated from a sea by a sand barrier overtopped with high sand dunes. The lagoon has been fed since the Middle Holocene by the Sebennitic branch of the Nile and marine intrusions through the Bughaz inlet. A sediment core (BO-1) was collected at the northeastern shore of the lagoon and sampled at centennial scale resolution in order to reconstruct the development of the lagoon. The results show that an initial and limited lagoon had developed at the end of the Early Holocene, but after a dry period ca. 7.2 cal ka BP it has been progressively transformed into a marshy area, with occasional inflows of sea water. Lower water level and higher salinity of the Burullus Lagoon at 6.0-5.5 and 4.8-4.2 cal ka BP reflected droughts in the Nile catchment. Thereafter, the river reactivated in the Burullus Lagoon area, and since 2.8 cal ka BP was accompanied by occasional inflows of sea water. Since ca. 0.8 cal ka BP, increased fluvial activity occurred in this part of the Nile delta, which terminated after construction of the Aswan dams in the twentieth century.
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Climate of the Past, 2021
In the densely forested Warmia and Masuria region
(northern Poland) there are many small endorhei... more In the densely forested Warmia and Masuria region
(northern Poland) there are many small endorheic lakes
characterized by their low sedimentation rate, which makes
them excellent archives of Holocene environmental and
palaeoclimatic change. Lake Młynek, located near the village
of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental
research supported with radiocarbon dates. Sediments
from this lake also contain unique information about
human impact on the environment, because a stronghold has
been operating on its northern shore since the early Iron Age
to the early Medieval period, giving the opportunity to correlate
palaeoenvironmental data with the phases of human
activity over the last 2400 years. During the second and third
centuries BCE the lake was surrounded by a dense deciduous
forest. From the first century BCE to second century CE the
forest around the lake was much reduced, which can be associated
with the first pre-Roman (La Tène) and Roman occupation
phase evidenced by the construction of the stronghold
located close to the lake. From the second up to ninth century
CE gradual restoration of the forest and a decline in
human activity took place, along with lake deepening and
the onset of a colder and humid climatic phase which corresponded
to the global cooling episode known as the Bond 1
event (1.5 ka BP). The next intensive phase of forest clearing
around the lake occurred between the 9th–13th century
CE as result of human activity (Middle Age settlement phase
of the stronghold). Whilst this period is marked by a warming,
the human impact which has transformed the landscape
likely overprints any signals of climate-driven environmental
changes.
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Review of Palaeobotany and Palynology, 2021
Water level changes Paleoenvironment Eemian interglacial Central Poland The main aim of the study... more Water level changes Paleoenvironment Eemian interglacial Central Poland The main aim of the study was to determine the environmental history and climatic change taking place during the Late Saalian/Eemian transition, particularly at the start of the Eemian interglacial. Paleolake sediments from two cores from the Garwolin Plain (Central Poland) were subjected to diatom analysis. Altogether, 63 genera including 335 species and varieties were recognized. A clear shift in diatom composition was observed, from an assemblage dominated by periphytic species including Fragilaria sensu lato taxa to a planktonic one comprising Cyclotella sensu lato species. These changes in diatom assemblages and the relative abundance of the dominant and subdominant taxa indicated fluctuations in water level and regional climate oscillation. The transition from the Late Saalian to the Eemian was marked by a gradual increase in the contribution of summer-blooming diatom species, indicating the presence of a growing season and humid warm conditions, together with a rise in water level. The predominance of an alkaliphilous assemblage indicates alkaline conditions in the paleolake. The local diatom assemblage zones correspond very closely with the palynostratigraphy of the period under examination.
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Quaternary International, 2021
In the region of 20 newly-found fossil lakes in the Garwolin Plain (Central Poland), formed durin... more In the region of 20 newly-found fossil lakes in the Garwolin Plain (Central Poland), formed during the Eemian interglacial (MIS 5e), the Kozłów site is considered one of the longest examples of sequences of palaeolake deposits. Pollen investigations have revealed an entire Eemian interglacial (MIS 5e) with a very long hornbeam phase. Repeated coring allowed for high-resolution pollen and diatom analysis to be used in tracing climatedriven palaeoenvironmental changes during the mid-and late-Eemian. The resulting thick series of organogenic deposits from Kozłów joins the collection of existing high-resolution long records of this interglacial in central-eastern Europe. It should be emphasized that a very good correlation was found between palynological and diatom data, which allows for drawing consistent conclusions. The warm and humid climate of the Corylus phase at the onset of the mid-Eemian was marked by a great abundance of planktonic Cyclotella sensu lato species, which indicate a rising water level, increased water temperatures, thermal stratification and a warm-wet climate. In the diatom zones correlated with the Carpinus phase, a distinct change was observed, from an assemblage dominated by planktonic species to one composed of benthic ones, including Fragilaria sensu lato taxa. The greater frequency of oceanic air masses must have affected the humidity and thermal conditions in lake and its surroundings in the first part of the interglacial optimum. Climate changes are very clearly visible at the transition between Carpinus and Picea-Abies zones, which were caused by increased influence of continental air masses. However, in the Middle Eemian no drastic changes were observed in both the pollen and diatom records. In the upper part of the core, represented by Pinus pollen, the presence of cold-loving diatom species, and an increase of green algae Pediastrum spp. point to a drop in temperatures at the close of the interglacial. The pollen results were compared to the well-recognized mid-to late-Eemian successions from Poland and West Europe.
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Lakes & Reservoirs, 2020
The present study focused on biomonitoring approaches involving the phytoplankton composition, de... more The present study focused on biomonitoring approaches involving the phytoplankton composition, density and diversity, and their relationships, with changes in environmental variables, and to determine the pollution status of Krishnasayar Lake in the Burdwan District of West Bengal, India. A total of 29 phytoplankton taxa belonging to Chlorophyceae (13), Cyanophyceae (9), Bacillariophyceae (5) and Euglenophyceae (2) were observed. The phytoplankton density exhibited a maximum value of 12,633 cells/litre in the post-monsoon season and a minimum value of 7,266 cells/litre in the pre-monsoon season. The results of two multivariate proficiencies (cluster analysis; CCA) indicated the distribution of phytoplankton groups are influenced by pH, electrical conductivity, and the nitrate, phosphate, potassium and dissolved oxygen concentrations. Various diversity indices, including the Shannon-Wiener Diversity Index, Gleason Species Richness Index, Pielou Evenness Index and Naughton Dominance Index, were explored to illustrate the seasonal phytoplankton fluctuations. The Shannon-Wiener Diversity Index values (2.524, 2.331 and 2.666, respectively, for the pre-monsoon, monsoon and post-monsoon seasons) indicate the moderation level of pollution status of the lake. The present study also highlights biomonitoring is a reasonable technique for establishing ecological conditions of lakes by considering the organisms within them, including planktonic algae, macrophytes, benthic mac-roinvertebrates, crustaceans and fishes on the basis of a single indicator species or a combination thereof. The present study used planktonic algae to determine changes in surrounding environmental conditions. As some of the studied phytoplankton species exhibit specific ecological preferences, their presence can indicate the health of that system. As examples, Coelastrum microporum, Pandorina morum and Euglena viridis indicate high levels of organic pollution. Krishnasayar Lake is integrated with the Krishnasayar ecological park, being affected by large levels of anthropogenic disturbance attributable mostly to uncontrolled and careless activities of some visitors, annual cultural activities, other programmes, etc., meaning relevant management activities are needed to protect the lake from further degradation. K E Y W O R D S biomonitoring study, freshwater lake, Phytoplankton
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Papers by Abdelfattah Zalat
of diatom floristics, ecology, biogeography, and their significance in environmental and climate reconstruction
in Poland. The study is based on the analysis of 821 sediment samples taken from different lakes in northern
Poland, besides 8 borehole-originated from the Eemian paleolakes sites in central Poland. The preceding diatom
results in published papers included the diatom flora that were recorded from different habitats in Poland are
mentioned in the present work to complete the Polish diatoms list. The current work is the first part in a series
of monographs dealing with the diatom taxa belonging to classes Coscinodiscophyceae, Mediophyceae and subclass
Fragilariophycidae. A total of 269 diatom species and varieties belonging to 38 genera are recognized. The
checklist is comprising 86 entries of Coscinodiscophyceae that includes all radial centric diatoms and 183 taxa of
Fragilariophyceae that includes araphid pennate diatoms. Of these 97 diatom taxa are represented as a new record
for Poland and 12 new combinations and new varieties. A detailed diatom description, distribution in Poland, and
autecological information are presented to round up the content of this volume and documented with 120 plates
including 2423 excellent light micrographs of diatom taxa, which allows for a better understanding of morphology
to aid in the identification. This work is proposed to contribute towards a general view of the high diatom biodiversity
that characterizes Polish ecosystems and provides a revised diatom checklist from Poland. Additionally, it
offers the first taxonomic and autecological catalog, which will be significant in the assessment of the water quality
monitoring, paleoenvironmental interpretation, and construct the paleoclimate changes.
(northern Poland) there are many small endorheic lakes
characterized by their low sedimentation rate, which makes
them excellent archives of Holocene environmental and
palaeoclimatic change. Lake Młynek, located near the village
of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental
research supported with radiocarbon dates. Sediments
from this lake also contain unique information about
human impact on the environment, because a stronghold has
been operating on its northern shore since the early Iron Age
to the early Medieval period, giving the opportunity to correlate
palaeoenvironmental data with the phases of human
activity over the last 2400 years. During the second and third
centuries BCE the lake was surrounded by a dense deciduous
forest. From the first century BCE to second century CE the
forest around the lake was much reduced, which can be associated
with the first pre-Roman (La Tène) and Roman occupation
phase evidenced by the construction of the stronghold
located close to the lake. From the second up to ninth century
CE gradual restoration of the forest and a decline in
human activity took place, along with lake deepening and
the onset of a colder and humid climatic phase which corresponded
to the global cooling episode known as the Bond 1
event (1.5 ka BP). The next intensive phase of forest clearing
around the lake occurred between the 9th–13th century
CE as result of human activity (Middle Age settlement phase
of the stronghold). Whilst this period is marked by a warming,
the human impact which has transformed the landscape
likely overprints any signals of climate-driven environmental
changes.
of diatom floristics, ecology, biogeography, and their significance in environmental and climate reconstruction
in Poland. The study is based on the analysis of 821 sediment samples taken from different lakes in northern
Poland, besides 8 borehole-originated from the Eemian paleolakes sites in central Poland. The preceding diatom
results in published papers included the diatom flora that were recorded from different habitats in Poland are
mentioned in the present work to complete the Polish diatoms list. The current work is the first part in a series
of monographs dealing with the diatom taxa belonging to classes Coscinodiscophyceae, Mediophyceae and subclass
Fragilariophycidae. A total of 269 diatom species and varieties belonging to 38 genera are recognized. The
checklist is comprising 86 entries of Coscinodiscophyceae that includes all radial centric diatoms and 183 taxa of
Fragilariophyceae that includes araphid pennate diatoms. Of these 97 diatom taxa are represented as a new record
for Poland and 12 new combinations and new varieties. A detailed diatom description, distribution in Poland, and
autecological information are presented to round up the content of this volume and documented with 120 plates
including 2423 excellent light micrographs of diatom taxa, which allows for a better understanding of morphology
to aid in the identification. This work is proposed to contribute towards a general view of the high diatom biodiversity
that characterizes Polish ecosystems and provides a revised diatom checklist from Poland. Additionally, it
offers the first taxonomic and autecological catalog, which will be significant in the assessment of the water quality
monitoring, paleoenvironmental interpretation, and construct the paleoclimate changes.
(northern Poland) there are many small endorheic lakes
characterized by their low sedimentation rate, which makes
them excellent archives of Holocene environmental and
palaeoclimatic change. Lake Młynek, located near the village
of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental
research supported with radiocarbon dates. Sediments
from this lake also contain unique information about
human impact on the environment, because a stronghold has
been operating on its northern shore since the early Iron Age
to the early Medieval period, giving the opportunity to correlate
palaeoenvironmental data with the phases of human
activity over the last 2400 years. During the second and third
centuries BCE the lake was surrounded by a dense deciduous
forest. From the first century BCE to second century CE the
forest around the lake was much reduced, which can be associated
with the first pre-Roman (La Tène) and Roman occupation
phase evidenced by the construction of the stronghold
located close to the lake. From the second up to ninth century
CE gradual restoration of the forest and a decline in
human activity took place, along with lake deepening and
the onset of a colder and humid climatic phase which corresponded
to the global cooling episode known as the Bond 1
event (1.5 ka BP). The next intensive phase of forest clearing
around the lake occurred between the 9th–13th century
CE as result of human activity (Middle Age settlement phase
of the stronghold). Whilst this period is marked by a warming,
the human impact which has transformed the landscape
likely overprints any signals of climate-driven environmental
changes.
Fragilariophycidae. A total of 269 diatom species and varieties belonging to 38 genera are recognized. The checklist is comprising 86 entries of Coscinodiscophyceae that includes all radial centric diatoms and 183 taxa of Fragilariophyceae that includes araphid pennate diatoms. Of these 97 diatom taxa are represented as a new record for Poland and 12 new combinations and new varieties. A detailed diatom description, distribution in Poland, and autecological information are presented to round up the content of this volume and documented with 120 plates
including 2423 excellent light micrographs of diatom taxa, which allows for a better understanding of morphology to aid in the identification. This work is proposed to contribute towards a general view of the high diatom biodiversity that characterizes Polish ecosystems and provides a revised diatom checklist from Poland. Additionally, it offers the first taxonomic and autecological catalog, which will be significant in the assessment of the water quality monitoring, paleoenvironmental interpretation, and construct the paleoclimate changes.