1,252 research outputs found
Reproductive potential of yellow water-lily (Nuphar lutea) in the conditions of lake ecosystems
Nuphar lutea (L.) Sm. (Nymphaeaceae Salisb.) belongs to the category of highly active cenose-forming plants in water bodies and water flows. The material for study of morphological peculiarities and seed productivity of the fruits of this species was collected mainly in the lake ecosystems of the Central Part of European Russia and Republic of Belarus. In the study we used biomorphological and ontogenetic approaches. Seed productivity was surveyed by direct count of number of seeds in the fruit. By abundance (in descending order), the significant reliable inter-lake differences in a number of morphological parameters of the fruit fall into the following sequence: number of rays of stigma of fruit (in six pairs of lakes) > length of fruit (in four pairs of lakes) > diameter of the stigma of fruit (in three pairs of lakes) > diameter of fruit (in two pairs of lakes) > length of the neck of the fruit (in one pair of lakes). Intra-regional differences in certain morphological parameters of fruits (by number of rays of stigmas) were most notably manifested only in the Belarus lakes which are similar by trophic status. All the differences in the fruits’ morphology could be due to differences in the habitat by the amount of nutrients in water and soil. The amount of seed productivity of the fruits from N. lutea varies broadly. Analysis of this parameter depending on the character of soils in which the plants grew indicated reliable results only in the case of muddy (296 ± 81) and sandy soils (179 ± 13). We determined that distribution of generative diasporas of N. lutea across large distances is related not only to presence of floating ability in the seeds, but also the “multi-step” process of their release: first – mericarps from fruits, and then seeds from mericarps. In the experimental conditions, most seeds directly sunk to the bed (70%) and the rest continued to float on the surface of the water during a month. Low germination of the seeds of the water-lily in the laboratory conditions (4–6%) with use of different means and terms of dry stratification was due to the fact that they have an organic morphophysiological intermediate type of rest. Having such a mechanism causes portioned and prolonged germination, allowing the species to survive in non-favourable conditions and accumulate generative diaspores in the soil. Despite the fact that the initial stages of ontogenesis in the laboratory and natural conditions have no significant differences, we found polyvariance in their tempo of development. First of all, this is related to different dates of transition of the plant from one age state to another. In the case of N. lutea, one should also note the morphological polyvariance of ontogenesis related to change in morphologic characteristics of plants depending on the water level. The obtained results give a more complete picture of the peculiarities of generative reproduction of N. lutea, necessary for understanding the ecosystem role of this plant and its impact on biological processes in water bodies
Impact monitoring of mining enterprises of Kursk magnetic anomaly on hydro ecological river situation of the Belgorod region
The results of contrastive analysis of hydrochemical state of surface water bodies exposed to the impact of mining enterprises, by way of example of small rivers of the Belgorod region, according to the results of exploration carried out in the years 2009-201
Regional manifestations of changes in atmospheric circulation in the Central Black Earth region : by the example of Belgorod region
The aim of this work is the estimation of the reasons of occurrence of the area of dangerous hydrometeorological phenomena and the analysis of the circulation processes, leading to the establishment of extreme weather conditions in the region. Using the calendar of the consistent changes of elementary circulation mechanisms and daily observations of the weather in the south of Central Black Earth region (by the example of Belgorod region).yesBelgorod State National Research Universit
The occurrence of extreme monthly temparatures and precipitation in two global regions
There has been a lot of focus on the occurrence of extreme weather events and a possible connection to climate change and variability. Much of this work has been related to individual events, rather than for long periods of time. This work will examine the occurrence of extreme conditions in the monthly temperature and precipitation for two geographically disparate regions of the Northern Hemispher
Influence of long- and short-term climatic changes on chernozem soils : Central Chernozem region of Russia
The main purpose of this article is the identification of forest-steppe and steppe chernozem soils (Eastern European Mollisols) reactions to climate change with different periodicitiesyesBelgorod State National Research Universit
Regional specificity of the climatic evolution of soils in the southern part of Eastern Europe in the second half of the Holocene
The analysis of characteristic features of chernozems and chestnut soils of different ages that have been formed in the south of the East European Plain in the past 5000 years attests to the spatial and temporal heterogeneity of the rate and direction of pedogenetic processes, i.e., to the metachronous development of the soil cove
Current hydroecological situation of the Starooskolsko-Gubkinsky mining region on the example of the Oskolets River
The results of the hydroecological study of the small Oskolets river in the area of influence of mining enterprises are presented. It is shown that the residential industrial flow of Gubkin city has a leading influence on the hydrochemical situation. Discharges of drainage waters made by the Lebedinsky mining and processing plant have a definite impact on the hydro-ecological situation with respect to the content of fluorine and lead compounds, and occasionally with respect to nitrogen compound
A comparison of bioclimatic potential in two global regions during the late twentieth century and early twenty-first century
This work will evaluate the growing season conditions using indexes that combine growing season temperature and precipitation such as the hydrothermal coefficient (HTC) and the bioclimatic potential (BCP). Also, the interannual variability of these indexes in both regions was examined. In the Belgorod region, the increase in temperature combined with little change in precipitation produced mixed results in interpreting these indexe
Reconstruction of Zigzag Graphene Edges: Energetics, Kinetics and Residual Defects
Ab initio calculations are performed to study consecutive reconstruction of a
zigzag graphene edge. According to the obtained energy profile along the
reaction pathway, the first reconstruction step, formation of the first
pentagon-heptagon pair, is the slowest one, while the growth of an already
nucleated reconstructed edge domain should occur steadily at a much higher
rate. Domains merge into one only in 1/4 of cases when they get in contact,
while in the rest of the cases, residual defects are left. Structure, energy
and magnetic properties of these defects are studied. It is found that
spontaneous formation of pairs of residual defects (i.e. spontaneous domain
nucleation) in the fully reconstructed edge is unlikely at temperatures below
1000 K. Using a kinetic model, we show that the average domain length is of
several m at room temperature and it decreases exponentially upon
increasing the temperature at which the reconstruction takes place.Comment: 5 pages, 4 figure
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