projective cover
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2021 ◽  
Vol 2103 (1) ◽  
pp. 012155
Author(s):  
V S Goryainov ◽  
A A Buznikov

Abstract The influence of pollutants on the spectral properties of common buckwheat (Fagopyrum esculentum) has been investigated insufficiently, compared to the cereals from the Poaceae family. A two-stage spectral survey has been carried out, growing common buckwheat in containers with set concentrations of copper(II) sulfate in soil both in laboratory conditions and in the open air. Spectral distributions of diffuse reflectance of the plants were registered in the range of 400 – 1100 nm, and spectral indices were calculated, using wavelengths corresponding to spectral features of plant pigments. Simultaneously, digital photos were taken to account for projective cover of the plants. Four spectral indices were found to depend quantitatively on pollutant concentration, three of them taking extreme values at the time of maximal projective cover. When growing buckwheat in the open air, lower temperatures and higher irradiation lead to closer values of spectral indices corresponding to different copper concentration, than in laboratory conditions. The results show the usability of common buckwheat as an indicator of soil pollution by copper.



2021 ◽  
Vol 22 (5) ◽  
pp. 706-714
Author(s):  
O. A. Timoshkin ◽  
O. Yu. Timoshkina ◽  
E. V. Timoshchuk

In 2019-2020, the quality of lawn-type grass mixtures based on creeping clover (Trifolium repens L.), meadow fescue (Festuca pratensis), pasture ryegrass (Lolium perenne) and meadow bluegrass (Poa pratensis) was evaluated in the conditions of the forest-steppe of the Middle Volga region (Penza region). The studied factors are the composition of the mixtures (creeping clover + bluegrass component), the seeding rates of the components (40 + 70 %; 55 + 55 %; 70 + 40 %) and the background of mineral nutrition (without fertilizers, P45K45, N30P45K45). The growing season during the years of research was characterized by arid conditions, the hydrothermal coefficient (HTC) for the period May-September in 2019 was 0.79, in 2020 - 0.76. On average, over two years of grass mixtures of creeping clover with meadow bluegrass at a seeding rate of 40 + 70 % and 70 + 40 % (from the seeding rate in pure form), creeping clover with meadow fescue with a seeding rate of 70 + 40 % components at all doses of mineral fertilizers had the highest comprehensive assessment of the quality of the lawn. The grass mixtures of creeping clover with meadow bluegrass (70 + 40 %) and creeping clover with meadow fescue (70 + 40 %) against the background of application of N30P45K45 had the maximum indicators in terms of herbage density (1425 and 1475 pcs/m2), which significantly exceeded the control and the variant with the introduction of Р45К45. In these variants, the highest indicators of projective cover (97.5 %) and a comprehensive assessment of "excellent" and "highest quality". According to weediness, the crops were estimated at 1 point (slightly weedy), per 1 m2 of annual and biennial weeds there were 24-27 pcs., rhizome weeds - less than 10 pcs. per 1 m2, the area of weed projective cover did not exceed 5 %.



Author(s):  
Vyacheslav A. Shushunov ◽  
◽  
Irina V. Shilova ◽  
Alena S. Parhomenko ◽  
Alexandr S. Kashin ◽  
...  

During the flowering period of Colchicum laetum Stephen (September 16–19, 2020), seven habitats were studied in the Volgograd region. C. laetum occurs on small (0.006–4 ha) unploughed areas of the steppes adjacent to gullies. In the community, 28 species of vascular plants were recorded, including C. laetum, only 10 species vegetated (from 2 to 7 in the community): Artemisia austriaca Jacq., A. santonicum L., Bassia prostrata (L.) Beck, Cynanchum acutum L., Dianthus polymorphus M. Bieb., Euphorbia seguieriana Neck., E. virgata Waldst., Grubovia sedoides (Pall.) GL Chu, Limonium bungei (Claus) Gamajun., Medicago falcata L. The participation of C. laetum is from single individuals to quite abundant, with a projective cover not exceeding 5%. A preliminary assessment of habitat by vegetation according to the Ramenskoye scales showed that one community is quite rich, one is rich and one is not rich. The humidification is from dry steppe to desert. Only one community does not experience anthropogenic impact. In the second the arrival of vehicles was marked. In the third grazing is carried out, accompanied by a failure.



Author(s):  
V. I Androsova ◽  
T. N. Chernisheva

At present, 264 species of lichens and allied fungi have been recorded for the territory of the BotanicalGarden of Petrozavodsk State University (Republic of Karelia) and 112 species have been found in its arboretum, wheremore than 200 species of introduced trees grow. The paper presents the results of studying the features of the epiphyticlichen cover of the collection trees of the arboretum of the Botanical Garden of PetrSU (Republic of Karelia). Results of thestudy are based on 1662 descriptions of the epiphytic lichen cover on 209 trees of coniferous species and 1150 descriptions –on 143 deciduous introduced species.The average total projective cover of lichens on the trunks of the studied coniferous introduced species reaches 18 % atthe trunk base, and 19 % – at a height of 130 cm above the ground. The number of species in the descriptions of epiphyticlichen cover varies from 0 to 12 (0.8 in average). The highest values of the projective cover of lichens and the numberof species in the descriptions were observed on the trunks of conifers of the genus Pinus, the lowest – on the trunks oftrees of the genus Thuja. The average total projective cover of lichens on the trunks of the studied deciduous introducedspecies was 8 % at the base, and 25 % – at a height of 130 cm above the ground. The number of species in the descriptionvaries from 0 to 9 (1.0 in average). The highest values of the projective cover of lichens and the number of species in thedescription are noted on the trunks of the genus Quercus, the lowest – on the trunks of trees of the genus Ulmus. Collectiontrees of arboretum tree represent a model object for observing the features of the formation of the epiphytic lichen cover



2021 ◽  
Vol 29 (3) ◽  
pp. 84-93
Author(s):  
O. M. Kunakh ◽  
O. I. Lisovets ◽  
N. V. Yorkina ◽  
Y. O. Zhukova

The ecological restoration of urban parks is used to increase their recreational attractiveness, improve air quality, mitigate urban heat island effects, improve stormwater infiltration, and provide other social and environmental benefits. The dynamics of plant communities after urban forest restoration requires investigation. The study assessed the impact of urban park reconstruction on the state of grass cover, phytoindication of changes in light regime caused by park reconstruction and found out the dependence of reliability of phytoindication assessment on the number of species in the relevant area. The study was conducted in the recreational area of the Botanical Garden of the Oles Honchar Dnipro National University (Ukraine). A tree plantation was created after the Second World War in the location of a natural oak forest. In 2019, a 2.8 ha area of the park was reconstructed. The samples were taken within polygons, two of which were placed in the reconstruction area and two of which were placed in a similar section of the park where no reconstruction was performed. During the reconstruction process, walkways were rebuilt, shrubs were removed, old, damaged trees were removed, and tree crowns were trimmed. Juvenile trees were planted in place of the removed old trees. Old outbuildings, which greatly impaired the aesthetic perception of the park, were also removed. Transport and construction machinery was involved in the reconstruction. A total of 65 plant species were found within the studied polygons. The number of herbaceous species in the park area after reconstruction was higher than without reconstruction. The crown closure in the reconstructed area was significantly lower than that in the untreated conditions. The phytoindication assessment showed that the light regime varies from the conditions suitable for the scyophytes (plants of typical foliage forests) to the conditions suitable for the sub-heliophytes (plants of light forests and shrubberies, or high herbaceous communities; lower layers are in the shade). The light regime in the park area after reconstruction was statistically significantly different from the regime in the untreated park area. The lighting regime after the reconstruction was favourable to sub-heliophytes, and without reconstruction the regime favoured hemi-scyophytes. Tree canopy crown closure negatively correlated with grass height and herbaceous layer projective cover. The tree canopy crown closure, grass height, and herbaceous layer projective cover were able to explain 86% of the phytoindication assessment of the lighting regime variation. These parameters negatively affected the light regime. The prospect of further research is to investigate the dependence of indicative reliability of the assessment of other environmental factors with the help of phytoindication depending on the number of species. In addition to the indication of traditional ecological factors it is of particular interest to clarify the aspect of the dynamics of hemeroby indicators as a result of park reconstruction.



2021 ◽  
Vol 208 (05) ◽  
pp. 40-54
Author(s):  
Regina Osipenko ◽  
Yuriy Zaripov ◽  
Sergey Zalesov

Abstract. The purpose is to establish the possibility of using mined brick clay pits for grazing livestock and preparing animal feed. The paper deals with the investigation of the above ground phytomass field layer (Fh) being formed dusing the natural growth of mined brick clay pits. Methodology. Species composition of the projective cover and aboveground phytomass were established on the counting areas of 0.5 × 0.5 sizes evenly spaced on the bottom and slopes of pit. At each of the quarry elements at least 30 registration sites were laid. In addition a similar number of registration sites were laid next to the quarry where clay was not mined. Researches were carried out in the district of pine-birch pre-forest steppe forests of the Trans Urals plain province, the west Siberian plain forest region. Results. It was found that the soil of mined out pits does not contain heavy metal and other chemical elements hazardous to animals. The total aboveground phetomass of Fh at the bottom and slopes of the quarry is 1101.1 and 812.6 kg/ha in absolutely dry, state, respectively. The total projective cover at the bottom of the quarry 3 years after the technical stage of reclamation is 64.7 % and on the slopes 42.5 %. The presence of meadow species in the composition, in particular of legumes family (Vicia cracca L.; V. hybridum L.; V. sativa L.; V. vernus L.; V. sylvatica L.; Trifolium pretense L.; T. lupinaster L.; T. repens L.; T. hybridum L.; T. medium L.; Lathyrus pratensis L.; Melilotu salbus Medikus; M. officinalis L. Pall.; Medicago lupulina L.) indicates a high feed value of FR. Scientific novelty. The transfer of mined out brick clay pits for temporary agricultural use will contribute at the formation of soil on the bottom and slopes of the quarry and ultimately, increase the productivity of future plantations.



2021 ◽  
Vol 10 (2) ◽  
pp. 18-23
Author(s):  
Yana Andreevna Bogdanova ◽  
Nataliya Vladimirovna Prokhorova ◽  
Lyudmila Mikhailovna Kavelenova

The paper deals with ecological conditions and peculiarities of bryoflora of artificial pine communities of the Buzuluksky pine forest and the Krasnosamarsky forest. The authors have revealed that the pine plantings of the Buzuluksky pine forest are characterized by a lower soil moisture and nitrogen supply than similar communities of the Krasnosamarsky forest in accordance with the criteria of D.N. Tsyganov scales. In addition, all communities belonging to the same territory show differences in the acidity and salt regime of soils as well as in moisture contrasts. The differences seem to be the result of a specific manifestation of parallel multidirectional successional processes (afforestation and steppe formation). For the bryofloras of the studied artificial pine communities, a significant similarity level (Czekanowski-Srensen index of 0,7) and close values of the projective cover and vitality of bryophytes have been shown. However, the substrate preferences of bryophytes are significantly different: 85% of the species grow on soil in the Buzuluksky pine forest, while 52% of the species grow on soil and 39% of the species grow on decaying wood in the Krasnosamarsky forest. In addition, more intensive sporulation of bryophytes has been noted in artificial pine communities of the Krasnosamarsky forest and the share of dominant species in the projective cover is 47,7% there, and their share is 83,4% in the Buzuluksky pine forest. The authors have suggested that genetic polymorphism should underlie the revealed differences in the species similarity of bryofloras. Its manifestation is influenced, among other things, by the stage of ecological succession of plant communities in which bryophytes grow. It is the result of the implementation of strategies for bryophytes adaptation to existing conditions and reflects the stage of bryoflora formation.



Author(s):  
Sofia Ercolanoni ◽  
Alberto Facchini

AbstractWe describe the structure of the projective cover of a module $$M_R$$ M R over a local ring R and its relation with minimal sets of generators of $$M_R$$ M R . The behaviour of local right perfect rings is completely different from the behaviour of local rings that are not right perfect.



2021 ◽  
Vol 10 (1) ◽  
pp. 102-106
Author(s):  
Ksenia Vyacheslavovna Malakhova

Thalli of epigeic lichenized fungi of the genus Cladonia P. Browne are sources of high biological activity substances with a proven pharmaceutical potential. Its necessary to study characteristics of the accumulation of biomass by thalli, as well as conditions affecting the accumulation of secondary metabolites by lesions. For the first time, studies of the primary productivity and concentrations of secondary metabolites in lichens of the genus Cladonia in pine forests in the center of the European part of Russia are presented on the example of the Kostroma Region. The primary productivity of bushy lichens of the genus Cladonia in the pine forests of the Kostroma Region is in the range of 16,0534,72 g/m per year for C. arbuscula and 14,7028,18 g/m per year for C. rangiferina. The weight gain of the living part of the subset is in direct proportion to the intensity of sunlight: the optimum for C. arbuscula is 41006100 lx (0,0250 g/year), for C. rangiferina it is 38005800 lx (0,0407 g/year). The influence of abiotic factors (biotope humidity and sunlight intensity) on the parameters of primary productivity and the accumulation of secondary metabolites by thalli was revealed. The influence of biotic factors is manifested on the projective cover of species. The highest values of the projective cover, 85,67% (C. arbuscula) and 61% (C. rangiferina), are confined to well-illuminated biotopes with rarefied sunlight (thin sphagnum pine forest, sphagnum-heather pine forest slope). The maximum amount of acetone extract of secondary metabolites per weight of air-dry raw material of lichenized fungi of the genus Cladonia was isolated from well-illuminated areas of pine forests at 58007400 lx (11,541 and 15,916 mg/g q.s. of C. rangiferina and C. arbuscula raw materials, respectively). The increased humidity of the biotope and shading conditions slow down the accumulation of secondary metabolites in the subsets.



Author(s):  
Ilya B. Kucherov ◽  

The research deals with recent invasions of bird-dispersed shrubs in specially protected natural reservations of St.Petersburg and Leningrad Region. The results of bird-dispersed woody species inventory in 5 partial nature reserves and nature sanctuaries of the area (See Fig. 1), based upon the extensive phytocoenological research data of 2014-2018, are given (See Table 1). Out of the adventive shrub species listed, the two most aggressive invaders were chosen according to their constancy and abundance in natural forest communities. These are Lonicera nigra in Komarovskiy Bereg [Komarovo Coast] Nature Sanctuary and Amelanchier spicata in Lisinskiy [Lisino] Partial Nature Reserve. For this purpose, distributions of these species are traced along with different forest types they invade, paying attention to species constancy and projective cover in different layers of forest communities (See Tables 2 and 4). Values of intralandscape species activeness, based upon the proper relevé sets, were also calculated for both aboriginal and adventitious plant species from different community types in each study area (See Tables 3 and 5). Lonicera nigra has never been detected as an invader before. It is presumably dispersed by robins, thrushes, and warblers, also by means of barochory and secondary hydrochory. The latter is proved by the occurrence of the oldest shrubs in riverine Norway spruce and Scots pine forests on the Littorine terrace of the Gulf of Finland within Komarovo Coast Nature Sanctuary. The results of secondary bird dispersal of this species are observed in sorrel spruce forests where the untypical low shrub layer is being formed (See Fig. 2). These plants are remote form brooks or drainage channels (See Table 2). L. nigra acts as one of the most active species in the sanctuary forest coenofloras studied (See Table 3). Nevertheless, floristic composition of these forest communities remains yet unchanged in its main features. The invasion of L. nigra in the sanctuary area was first mentioned in literature by NN Tzvelev in 2000 but it took place much earlier, as the ancestral plant specimens were likely to grow in a transplant nursery near the present-day sanctuary north-eastern border in the early XX-th century. According to Komarov Botanical Institute Herbarium (LE) data, the secondary area of L. nigra in Russia is restricted to several findings in the Karelian Isthmus. Amelanchier spicata, the June berry, listed among the most aggressive plant invaders in European Russia, is dispersed by thrushes along roads in forests and then invades sorrel and horsetail-peatmoss spruce and pine forests on southern-boreal watersheds in Lisino Reserve, often as a gap-filling species. It is less common and abundant in secondary birch and aspen forests. In contrast to Lonicera nigra, it is infrequent and never abundant in riverine forests (See Table 4), the fact probably explained by difference in prevailing bird distributor species. A. spicata is never found in feathermoss pine forests on fluvial-glacial sand as well as in dwarfshrub-peatmoss pine bog forests. The invasion of this species in the reserve area probably took place after 1984-1987 when the species was not registered in forest communities of the area according to the author’s personal observations. In 2017, the activeness of A. spicata is low in all the forest types it inhabits, being compared to that of the dominant aboriginal species (See Table 5). As follows from the correlation analysis results, no one of the discussed invaders affects the projective cover of any of the native plant species in both protected areas significantly. Speaking of Amelanchier spicata, it is in fact far less aggressive than in the more southern areas of Central and Southern Russia where the species transforms forest communities actively and affects aboriginal field- and ground-layer plants negatively, even as far as to the extinction of some of the latter, as it is well-known from the literature on the subject. We are just at the beginning of the invasion process in the forests of the Russian North-West yet. The invasion of both species studied is likely to be connected with the climate change processes. The research reveals that a neglected adventive species, persisting long within a given area, may also suddenly become an aggressive invader (the case of Lonicera nigra). The invasion of adventive shrubs into the paludified forest communities, including those of the boreal peatmoss spruce forests which served as etalons of floristic stability quite recently, is also alarming.



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