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The Principal Threats to the Standing Water Habitats in the Continental Biogeographical Region of Central Europe

Abstract

This paper discusses threats of standing water habitats of high importance to the European Community in the Continental Biogeographical Region (CBR) of Europe, specifically in Poland, as a reference. The study covers five standing water habitats types distinguished in Natura 2000: 3110, 3130, 3140, 3150, 3160, occurring in 806 Special Areas of Conservation (SACs) in Poland. The most significant threats to standing water habitats in the Continental biogeographical region, result from human-induced changes in hydrological conditions that have modified whole natural systems. Based on multivariate analysis, we found that significant differences in the conservation status of the standing water habitats resulted from a variety of threats, pressures, and activities, among which the most significant are decreased and unstable water resources (3110, 3130, 3140, 3150, 3160), fishing and harvesting aquatic resources (3110, 3130, 3140, 3150, 3160), pollution from use of the catchment (3130, 3140, 3150), improper management and use of the agricultural catchment (3110, 3130, 3140, 3150, 3160) and forest catchment (3110, 3140, 3160), urbanisation, residential and commercial development (3150, 3140), transportation and service corridors (3140> 3160 > 3110, 3150), including parking areas (3140), changes in biocenotic evolution, succession, plant species composition (3110, 3130, 3140, 3150, 3160), succession of invasive species (3130), and more intense touristic exploration (3110, 3130, 3140, 3150, 3160). Only in the case of habitats 3110, 3130, 3140 changes in their conservation status have been associated with climate change.

Open access
The Role of Hillshade, Aspect, and Toposhape in the Woodland Dieback of Arid and Semi-Arid Ecosystems: A Case Study in Zagros Woodlands of Ilam Province, Iran

Abstract

Soil moisture plays a key role in the ecological capability of arid and semi-arid woodland. Reducing soil moisture due to frequent droughts causes pest prevalence and disease outbreak and the consequence of forest dieback. On the other hand, soil moisture is strongly correlated with the amount of radiation received on the Earth’s surface. The sun’s radiation is traditionally described often by aspect and sometimes by toposhape. The use of the hillshade map for estimating solar radiation is possible through developing GIS. The present study aimed to compare the relationship and the ability of these indices to describe the phenomenon of arid and semi-arid woodland decline better and more accurately in a case study in the west of Iran. To this aim, the aspect and toposhape layers were generated in 5 and 12 classes, respectively. Then, the hillshade map in range of 0-255 was made during the peak of summer heat. The comparison of the dieback ratio in the three characteristic histograms showed that the shade index, unlike the other two indicators, had a significant effect on forest drought (R2=0.91 for linear equation and R2=0.94 for quadratic equation). The results indicated that the application of hillshade in describing and analysing ecological processes by relying on soil moisture such as woodland dieback is superior to the other two indicators. It is suggested that this index be used to obtain a risk model to predict woodlands dieback which are under the pressure of frequent droughts due to climate change or other mortal factors.

Open access
A New Method for the Estimation of Hydraulic Permeability, Coefficient of Consolidation, and Soil Fraction Based on the Dilatometer Tests (DMT)

Abstract

The main issue of the paper is the estimation of soil hydraulic permeability based on the DMT test. DMTA, DMTC and SASK methods performed in the Nielisz dam, Stegny and the SGGW Campus of the Warsaw University of Life Sciences sites are described. The article presents the implementation of the dilatometer Marchetti test (DMT) in the determination of soil fraction and effects of its occurrence in the subsoil, tested in the Nielisz dam located in the Wieprz river valley in the Lublin province, and in various sites in Warsaw (Stegny site and SGGW Campus of the Warsaw University of Life Sciences). In order to acquire the needed data, the flat dilatometer test (DMT) method was used. A direct and indirect pressure methodology of interpreting soil swelling was characterized in the article. The paper shows the possibilities of determining sand, silt and clay soil fractions based on po and p 1 pressures from dilatometer tests (DMT) and the effective (σvo) and total (σvo) vertical in situ overburden stress. Additionally, the main advantage of this paper is the proposal of use of a new chart to determine hydraulic permeability and soil fraction, based on DMT tests.

Open access
Shear Strength Enhancement of Cemented Reinforced Sand: Role of Cement Content on the Macro-Mechanical Behavior

Abstract

Sands reinforced by hydraulic binders (cement) have constituted in recent decades a major asset for the expansion of several areas of engineering. The mechanical behavior of sand-cement mixtures has undergone some controversies studied on the Chlef sand. In this paper, we present an experimental study to investigate the mechanical behavior of a sandy soil reinforced by a hydraulic binder (cement), using the direct shear apparatus emphasizing on the shear strength characteristics and the vertical deformation variation of cemented reinforced sand. The parameters used in this study are mainly: relative density (Dr = 80%), normal stress (σn = 100, 200, 400 kPa), water content (3, 7 and 10%), cement content (2.5, 5, 7.5 and 10 %) and cure time (7, 14 and 28 days). The experimental results show that the mechanical characteristics in terms of internal cohesion (C) and internal frication angle (φ) give a better mechanical performance with the binder inclusion, and the cure conditions play an effective role on the improvement of the shear strength. This result also showed that 10% of the cement content gave us a maximum value of shear strength and an optimal influence on the mechanical characteristics. The addition of cement not only improves the shear strength of soil, but also provides diversity in the resistance against the deformations imposed load, which can be established by a dilatant character.

Open access
Nevşehir Castle Region in Turkey Interpreted by the Use of Seismic Surface Wave and Electrical Resistance Measurements Together

Abstract

The underground city beneath the Nevşehir Castle located in the middle of Cappadocia region in Turkey with approximately cone shape is investigated by jointly utilizing the modern geophysical techniques of seismic surface waves and electrical resistivity. The systematic void structure under the Nevşehir Castle of Cappadocia, which is known to have widespread underground cities, is studied by the use of 33 separate two-dimensional profiles ~4-km long where electrical resistivities and seismic surface waves are concurrently measured. Seismic surface wave measurements are inverted to establish the shear-wave velocity distribution while resistivity measurements are inverted to resolve the resistivity distribution. Several high-resistivity anomalies with a depth range 8-20 m point to a systematic void structure beneath the Nevşehir Castle. We were able to effectively isolate the void structure from the embedding structure since the currently employed resistivity instrument has provided us high resolution quality measurements. Associated with the high resistivity anomalies there exist low-velocity depth zones acquired from the surface wave inversions also pointing to a systematic void structure where three-dimensional visualization techniques are used to show the extension of the void structure under the studied area.

Open access
A new Hauterivian palynoflora from the Vale Cortiço site (central Portugal), and its palaeoecological implications for western Iberia

Abstract

Palynofloral assemblages are an invaluable source of information about the interactions between fossil plants and their environments. Here we describe a new Early Cretaceous palynoflora from the Lusitanian Basin in the Estremadura region of central western Portugal. A palynological assemblage of 28 genera and 40 species was extracted from 14 samples collected in the Vale Cortiço clay pit complex near the small village of Ameal (Torres Vedras Municipality). The source is a dark grey mudstone layer belonging to the lower part of the Santa Susana Formation, which is considered to be of early Hauterivian age. The palynoflora is dominated by fern spores and gymnosperm pollen. Bryophyte and lycophyte palynomorphs are also present but subordinate. Angiosperm pollen and algal or dinoflagellate cysts were not recognised in the studied samples. The palynological assemblage represents mixed conifer forest with the ground cover and understorey vegetation dominated by ferns, with patchy occurrences of bryophytes and lycophytes. A riverine environment with surrounding vegetation of open woodland and ground cover primarily of ferns is strongly indicated for the region.

Open access
Structural Inversion Magnitude and its Impacts on the Hydrocarbon Accumulation

Abstract

West Wadi El-Rayan is located in the Western Desert at about 140 km SE of Cairo. Also, it lies between Gindi basin to the east and Abu Gharadig basin to the west. In order to construct a 3D structural model and to delineate the subsurface structure styles of the area, seismic structural interpretation and structural restoration are used. The structural geometry within the area is inverted half-graben, since the area was controlled by reactivation of older faults. The magnitude of the inversion-related shortening in the study area was estimated and was suggested to be strong. The result of the strong inversion magnitude occurred toward northeast of the study area can be concluded that, the area suffered shortening and part of the Jurassic / Early Cretaceous normal faults are reactivated as reverse faults. Also the cap, the main reservoirs and the source rock sections are brought to the surface and thus breached, as well any previous mature source rock becoming non-generative where the dry wells are located. However, any less severe inversion structure in this case where producing wells are located that remain buried and will have a better chance or preserving the structure geometry and therefore top and lateral seal.

Open access
The bivalve Cuneamya from the Late Ordovician of Bohemia

Abstract

The bivalve species Cuneamya catilloides from the Late Ordovician of Bohemia, previously assigned to the genus Grammysia, is revised. Cuneamya catilloides is an important element of the Modiolopsis Community Group in the Letná Formation. The genus Grammysia very probably does not occur in the Ordovician of Bohemia and is restricted to the Silurian and Devonian strata. Cuneamya catilloides with strong commarginal costae was probably an infaunal filter feeder. Cuneamya is a cosmopolitan genus, occurring on Avalonia, Baltica, Laurentia, Perunica and West Gondwana.

Open access
The calcareous nannofossils and magnetostratigraphic results from the Upper Tithonian–Berriasian of Feodosiya region (Eastern Crimea)

Abstract

This article is concerned with nannofossil study of Tithonian–Berriasian sediments of Eastern Crimea. The NJT 16, NJT 17a, NJT 17b, NKT, and NK 1 nannofossil zones were determined. The occurrence of Nannoconus kamptneri minor, one of the potential marker-types of the Tithonian–Berriasian boundary (the base of the NKT Zone) of the Tethyan sequence in the Feodosiyan section is assigned here to the Pseudosubplanites grandis ammonite Subzone and the magnetic Chron M18n. The base of the NKT Zone is closer to the Grandis Subzone base than to the base of the Jacobi Subzone. Contradictions in the interpretation of magnetic chrons obtained by the present authors (Arkadiev et al. 2018) and by Bakhmutov et al. (2018) might be caused by mistakes admitted in the latter work on the compiled section.

Open access
Cambrian hyoliths of the Příbram-Jince Basin (Barrandian area, the Czech Republic): A review of recorded taxa

Abstract

Hyoliths recorded from the middle Cambrian Jince Formation of the Barrandian area in the Czech Republic are reviewed and listed, based on various published papers printed since 1854. Up to now, only five species of hyolithids and three species of orthothecids have been reported, classified within seven genera. The reported material was collected from more than twenty small occasional outcrops and/or sections measuring up to several tens of meters in thickness, all situated exclusively in the area between the villages Felbabka and Čenkov in the Litavka River Valley. From the Paseky Shale member of the Holšiny-Hořice Formation at the Medalův mlýn locality, the first hyolith classified as “Hyolith genus and species indeterminate” is described. The new study of two specimens described and figured by Barrande in 1867 as Hyolithes primus made it possible to classify them as Jincelites vogeli and Jincelites sp. respectively.

Open access