15 research outputs found
Flora and vegetation of dry grasslands of Northeastern Ukraine, and problems of diversity conservation
The aim of this study was to describe the flora and vegetation of the grasslands of Northeastern Ukraine and to analyse how the steppe vegetation responds to grazing or its abandonment. We studied two gully systems in the east of the Kharkiv Region: the Regional Landscape Park “The Velykyi Burluk-Steppe” (steppe grasslands on chernozem soils; 10 sites) and the National NaturePark “Dvorichanskyi” (steppe grasslands on chalky outcrops; 5 sites). Longterm monitoring data exist for both these sites starting in 1991, shortly after grazing intensity reduced. We recorded the major grassland plant communities (reflecting their successional status) as well as their dominant species. Tree andscrub encroachment increased after management ceased. We conclude that (i) heterogeneous grazing (including ungrazed patches) in space and time is necessary in order to preserve grassland biodiversity in our study system; (ii) erosion of chalky outcrops (natural erosion as well as driven by cattle grazing) is a key factor promoting the richness of cretaceous species in steppe grassland
Grazing, abandonment and frequent mowing influence the persistence of the steppe marmot, Marmota bobak
The goals of the study were to illustrate how parameters of steppe marmot settlements change after abandonment of livestock grazing, to evaluate differences in vegetation characteristics between grazed and abandoned habitats, to find the links between these characteristics and the persistence of marmot settlements and to establish whether it is possible to maintain the food base of marmots by applying frequently repeated mowing. Data were collected in 1991–2016 in the steppe marmot (Marmota bobak) settlement in the Regional Landscape Park “The Velykyi Burluk-Steppe” (Kharkiv Region, Northeastern Ukraine). We found that grazing prolongs the period of active plant growth and supports a regrowth during periods of intensive feeding of all age groups of marmots. In abandoned habitats the vegetation period ended before the end of active feeding of reproductive females and juveniles. Tis resulted in lower reproductive success, which determines a decrease in the population and may in the future result in a larger decline of settlements. Frequently repeated mowing by a lawnmower at a cutting height of 6–9 cm prolongs the vegetation period and maintains a water content in the plants similar to that of grazed habitats throughout the active season of steppe marmots
Summer fire in steppe habitats: long-term effects on vegetation and autumnal assemblages of cursorial arthropods
Being an essential driving factor in dry grassland ecosystems, uncontrolled fires can cause damage to isolated natural areas. We investigated a case of a small-scale mid-summer fire in an abandoned steppe pasture in northeastern Ukraine andfocused on the post-fire recovery of arthropod assemblages (mainly spiders and beetles) and vegetation pattern. The living cover of vascular plants recovered in a year, while the cover of mosses and litter remained sparse for four years. The burnt site was colonised by mobile arthropods occurring in surrounding grasslands. The fire had no significant impact on arthropod diversity or abundance, but changed their assemblage structure, namely dominant complexes and trophic guild ratio. The proportion of phytophages reduced, while that of omnivores increased. The fire destroyed the variety of the arthropod assemblages created by the patchiness of vegetation cover. In the post-fire stage they were more similar to each other than at the burnt plot in the pre- and post-fire period. Spider assemblages tended to recover their pre-fire state, while beetle assemblages retained significant differences during the entire study period
New data on geochemical features, fluid mode, age and potential ore content of granitoids of Isherim anticlinorium (North Ural)
Granitoids of Ishirim anticlinorium which is one of the major Precambrian structures of the North Urals, are poorly studied by modern geochemical and isotope-geochronological methods that led to the existence of different points of view on formation conditions and age of these rocks. The authors performed a study of the composition of rocks from three massifs - Vels, Moiva and Pos’mak, by chemical analysis and ICP-MS; age determination on zircons by the methods of LA-ICP-MS and SHRIMP, as well as the study of the composition of rock-forming and accessory minerals using microprobe SX-100, which allowed us to obtain fundamentally new data about the age, fluid regime of formation and potential ore content of granitoids. It is shown that the granitoids were probably formed in environments of active continental margin and orogen; the first has the Ediacaran (567.2-558 Ma), the second - Cambrian (530.3-511.1 Ma) age. Discrete intervals of the formation and a fairly significant geochemical differences of Precambrian and Paleozoic granites, allow to attribute them to different complexes - the Ediacaran Moiva complex and Cambrian Vels complex. The complexes are different in composition of fluids which change over time from substantially chlorine to fluorine. With more ancient (Ediacaran) granitoids of Moiva massif can be associated gold-bearing Mo-W mineralization, and with Cambrian granites - rare-metal mineralization (W, Nb, Ta, REE)
Review of deep learning approaches in solving rock fragmentation problems
One of the most significant challenges of the mining industry is resource yield estimation from visual data. An example would be identification of the rock chunk distribution parameters in an open pit. Solution of this task allows one to estimate blasting quality and other parameters of open-pit mining. This task is of the utmost importance, as it is critical to achieving optimal operational efficiency, reducing costs and maximizing profits in the mining industry. The mentioned task is known as rock fragmentation estimation and is typically tackled using computer vision techniques like instance segmentation or semantic segmentation. These problems are often solved using deep learning convolutional neural networks. One of the key requirements for an industrial application is often the need for real-time operation. Fast computation and accurate results are required for practical tasks. Thus, the efficient utilization of computing power to process high-resolution images and large datasets is essential. Our survey is focused on the recent advancements in rock fragmentation, blast quality estimation, particle size distribution estimation and other related tasks. We consider most of the recent results in this field applied to open-pit, conveyor belts and other types of work conditions. Most of the reviewed papers cover the period of 2018-2023. However, the most significant of the older publications are also considered. A review of publications reveals their specificity, promising trends and best practices in this field. To place the rock fragmentation problems in a broader context and propose future research topics, we also discuss state-of-the-art achievements in real-time computer vision and parallel implementations of neural networks
The results of U-Pb SHRIMP-II dating of zircon from granitoids of Talitsky molybdenum-bearing massif (eastern slope of the Middle Urals)
Age position and geodynamic conditions of molybdenum metallization and productive granitoids of the Urals formation are very little studied now. This publication contains the results of isotopic dating of granites from Talitsa Cu-Mo-porphyry deposit which should help solve this problem. The timing of formation of the molybdenum-bearing granitoids of Talitsa deposit was determined by applying the U-Pb SHRIMP-II method through zircons (the Center for Isotopic Research of All Russian Geological Research Institute, St.Petersburg). The U-Pb-age has been calculated on 7 (from a total of 11 conducted) measurements with probability of concordanсе 0.996 and MSWD = 0.105 and it is 297.4 ± 2.3 Ma. The results of U-Pb dating are similar to before published Re-Os ages of Talitsa molybdenite deposit: 299.9 ± ± 2.9 Ma and 298.3 ± 1.3 Ma. These data establishes the new unknown before age level of molybdenum metallization. Until recently there has been only data on the Yuzhno-Shameiskoe molybdenum deposit connected with the subalkaline granites of Malyshevo massif which is younger: 277.1 ± 1.1 Ma. According to the received data, the intrusion of investigated granitoids happened practically at the same time as the formation of the wide-spread in the western slope of the Middle Urals intrusive bodies which are accompanied by gold metallization (Verkhisetsky, Shartashsky and others). With such close (practically the same) time of formation the rocks of molybdenum-bearing and gold-bearing massifs significantly differ in petrochemical peculiarities, which probably determines their metallogenetic specialization. Granitoids forming gold-bearing quartz veins on chemical composition are rocks of calc-alkaline series (typical exemple - Shartashskyi massif with Beriozovsk gold deposite). The granitoids productive on of Cu-Mo-porphyry type metallization together with large number of normal alkalinity rocks includes subalkaline rocks such as monzodiorites and quartz monzodiorites
GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
Abstract: GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phyto- coenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems
GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands
GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board