Search

The syntaxonomical diversity of the ruderal vegetation of the class Artemisietea vulgaris in the territory of Ukraine has been studied in 2015-2020. It is established that this class includes 58 associations from six alliances (Convolvulo arvensis- Agropyrion repentis, Arction lappae, Dauco-Melilotion, Onopordion acanthii, Medicagini falcatae-Diplotaxion tenuifoliae and Rorippo austriacae-Falcarion vulgaris) and two orders (Agropyretalia intermedio-repentis and Onopordetalia acanthii). Based on the results of the DCA-ordination analysis, it was found that the distribution of this type of ruderal vegetation is determined by the concentration of mineral nitrogen, the degree of aeration of the substrate, and the variability of moisture. At the level of high-rank syntaxa we didn't find only vegetation that was specific for sub-Mediterranean and Mediterranean regions as well as for eastern part of European russia. At the same time, we determined specific vegetation on the European scale from the territory of Ukraine. This is Crimean submediterranean xero-mesophytic ruderal vegetation and semiruderal meso-xerophytic vegetation united into two alliances – Medicagini falcatae-Diplotaxion tenuifoliae and Rorippo austriacae-Falcarion vulgaris. All associations within these alliances are also specific only for the territory of Crimea, characterized by the specific floristic structure and diagnostic species core, and didn't find in other regions of Ukraine. [ABSTRACT FROM AUTHOR]

Between 2015 and 2020 a study was conducted on the diversity of ruderal vegetation of the Stellarietea mediae class on the territory of Ukraine. It was discovered that this class consists of 48 associations from 12 alliances and 5 orders (Aperetalia spicae-venti, Atriplici-Chenopodietalia albi, Eragrostietalia, Papaveretalia rhoeadis, Sisymbrietalia sophiae). Based on the results of ordination analysis it was found that the distribution of annual ruderal communities is determined by the variation of moisture, soil aeration as well as carbonate and nitrogen content. [ABSTRACT FROM AUTHOR]

The data concerning epizootology of the tumor disease in Esox lucius L. in the Kiev Reservoir in the years 2000-2001 arc provided. No clear seasonal regularities in distribution of neoplasms over the reservoir were noted, whereas the age features of the disease occurrence can be revealed. Three stages in development of tumors and pathological processes are distinguished. [ABSTRACT FROM AUTHOR]

The expansion of ligulosis among fishes in different parts of the Kiev Reservoir was studied during 1997–2001. It is shown that mean numbers of fishes (Rutilus rutlilus. Blicca bjoerkna. Abramis brama. Abramis ballerus, Leucaspius delineatus) invaded by Ligula plerocercoids were 2.5 times higher in the upper part of the reservoir than that in its lower part. It has been stated the existence of an age dynamics in the intensity of infestation of white bream (Blicca bjoerkna) with Ligula, while seasonal dynamics was not detected. [ABSTRACT FROM AUTHOR]

Abstract: Ruban (this issue) raises two concerns regarding the onlap–offlap curve recently published by Eros et al. (2012) for the Donets Basin. One issue questions the use of the Carboniferous timescale presented in Eros et al. (2012) given that it differs from that of the Geologic Time Scale 2004 (Davydov et al., 2005). The second issue addresses three discrepancies between the Donets curve and “the available global eustatic curve” of Haq and Schutter (2008), bringing into question the degree to which the Donets onlap–offlap history might record regional tectonism to continental-scale mantle dynamics over glacioeustasy. The Carboniferous timescale (Davydov et al., 2010) used by Eros et al. (2012) incorporates new high-precision ID-TIMS U–Pb dates from tonsteins collected throughout the Donets Basin that are tied to stratigraphic sections and sequences referenced in Eros et al. (2012). This time-scale forms the basis of the Carboniferous interval in the latest edition of the Geologic Timescale 2012 (Davydov et al., 2012), which we consider the most appropriate for use in Carboniferous studies. Here we present a high-resolution correlation between the onlap and sea-level histories for the U.S. Midcontinent (Ross and Ross, 1987; Heckel, 2008), the Donets Basin, and the Pennine Basin (Waters and Condon, 2012) made possible by recently published chronostratigraphic constraints (Davydov et al., 2010; Schmitz and Davydov, 2012). This robust chronostratigraphically constrained comparison argues for a dominant eustatic driver on the observed hierarchy of stratigraphic cyclicity and inferred sea level variations on the 105 and 106-year scale in minimally the cross-Pangaean paleotropical regions. Existing discrepancies between these correlated records and the Late Paleozoic record of ‘modal mean of change in sea level’ (Haq and Schutter, 2008) awaits future inter-regional correlations of radiometrically and biostratigraphically well-constrained Carboniferous successions. [Copyright &y& Elsevier]

Abstract: The degree to which Permo-Carboniferous cyclothemic successions archive evidence for long-term variations in ice volume during the Late Paleozoic Ice Age is insufficiently resolved. Here we develop the sequence stratigraphy and onlap–offlap history for a 33-my interval of the Carboniferous using the U–Pb calibrated succession of the Donets Basin, Ukraine, in order to assess the relationship between sea-level, high-latitude changes in glacial extent, and climate. Integrated subsurface and outcrop data permit meter-scale correlation of 242 biostratigraphically constrained limestones and coals, and in turn individual cyclothems, across ~250km of the Donets Basin. Rapid uniform subsidence and basinwide continuity of marker beds indicate Pennsylvanian deposition under relatively stable tectonic conditions. Three scales of sequences (avg. durations of ~140ky, ~480ky and 1.6my) are recognized on the basis of stratigraphic stacking patterns and basinwide architecture of marine to terrestrial facies assemblages. The hierarchy of sequences and the geographic and stratigraphic positions of shifts in base-level sensitive facies across the Donets ramp permit the construction of an onlap–offlap history at a sub-400 ky scale. Major sea-level lowstands occur across the mid-Carboniferous boundary and during the early Moscovian. These lowstands coincide with glacial maxima inferred from high-latitude glacigenic deposits. The middle to late Pennsylvanian is characterized by a stepwise onlap, culminating in an earliest Gzhelian highstand, suggesting contraction of Carboniferous ice sheets prior to the initiation of Early Permian glaciation. The stratigraphic position of climate sensitive facies within individual Donets cyclothems indicates a turnover from seasonal sub-humid or semi-arid climate to everwet conditions during the late lowstand and maximum ice sheet accumulation. Comparison of the stratigraphic and aerial distribution of coals and evaporites in the Donets Basin with the onlap–offlap history further indicates everwet conditions during lowstands and inferred glacial maxima and drier climate during onlap and inferred ice sheet contraction at the intermediate (~0.8 to 1.6 my) and long (106 yr) time-scales. Taken together, the relationship between inferred climate and glacioeustasy suggests a likely teleconnection between high-latitude ice sheet behavior and low-latitude atmospheric dynamics. [Copyright &y& Elsevier]