scholarly journals The Role of Certain Species of Small Mammals in the Persistence of Natural Focality in the Territory of Forest-Steppe Zone of the Natural Tularemia Focus of the Stavropol Region

Author(s):  
B. I. Levchenko ◽  
L. V. Degtyareva ◽  
A. A. Zaitsev ◽  
M. P. Grigor’Ev ◽  
V. V. Ostapovich

Epizootiological monitoring of the forest-steppe area of the natural tularemia focus in the Stavropol region has revealed that the role of particular species of small mammals in the persistence of natural tularemia focality is unequal. Epizootic activity of the focus in 1959-1970 was determined by the numerous species of rodents: Microtus arvalis , mice of Syvaemus genus and Mus musculus . In 1972-2010 there occurred significant changes in the grouping of the main tularemia agent carriers under the influence of strong anthropogenic pressure. Nowadays the leading role is played by the widely-spread and subsistent mice of Sylvaemus genus and C. suaveolens , the latter ones being responsible for 31.2 % of overall, isolated from small mammals, tularemia agent strains. In addition to this, epizootic significance of M. arvalis has greatly changed. Index of strains isolated from field vole has lowered from 55.3 up to 28.4. Numbers of M. arvalis and Mus musculus are continuously on the low level, which is due to the absence of favorable breeding conditions. It reduces their impact on the persistence of natural focality in the territory under surveillance significantly.

2017 ◽  
Vol 6 (2) ◽  
pp. 18-23
Author(s):  
Elena Evgenievna Boryakova

The study of the nature reserve oak forest near the village of Pelya-Khovanskaya ecosystem was done in the region of Nizhny Novgorod. The investigated wood is unique for its complex structure. It is situated in the forest-steppe zone, characterized by a high species diversity of small mammals and vegetation, which indicates the complexity of trophic and spatial connections. Several series of sample plots were described: 41 of 2020 m and a number of 11 m sites, totaling 300. Abundance of species by Brown-Blanke scale and the number of specimens of adolescence were specified for each 1 sq. m. plot. Mammals were trapped with the help of trapping grooves and transects method. Vegetation cover is characterized by the presence of a clear intra-differentiation as well as the existence of two basic ecologo-coenotic groups/cores - the nemoral (with Pulmonaria obscura Dum. as the center species of the core) and the meadow-fringe. The most distinct group is formed by forest-shoot species. It can be explained by more forest-steppe rather than nemoral nature of vegetation. Small mammals are represented by the following species: common and small shrews, small forest mouse, yellow-throated and field mice and harvest mouse, vole-housekeeper, common, plowed and red voles, European mole. Two species among them - vole-housekeeper and mouse-baby - are listed in the Red Book of the Nizhny Novgorod Region. Matching burrows of mouse-like rodents with soil richness with nitrogen and humidity, two well-defined peaks are observed. The greatest number of burrows is found in places where the soil is high in nitrogen. Moles were found in areas with a large projective coating of Primula veris: coefficient Spearman rank 0,50. There was a negative correlation of the number of moles and vegetation covering of Pyrethrum corymbosum (-0,46), which is the marker of the driest parts in the forest. In general, the nature reserve oak forest near the village of Pelya-Khovanskaya is of considerable interest, both from botanical and from zoological point of view. Long-term studies of biocoenosis will allow to monitor the facility and to correct the proposed protective measures.


2021 ◽  
Vol 901 (1) ◽  
pp. 012007
Author(s):  
V M Kosolapov ◽  
V I Cherniavskih ◽  
E V Dumacheva ◽  
M N Marinich ◽  
L D Sajfutdinova ◽  
...  

Abstract We evaluated the stability of perennial legume and cereal grass species in artificial plant communities on permanent anti-erosion watercourses in the agroecosystems of the Belgorod region with active development of linear soil erosion. In the conditions of steppe and forest-steppe zones of the Belgorod region on permanently grassed watercourses in 2017-2019. varieties of perennial leguminous and cereal grasses: ‘Krasnoyaruzhskaya 1’ and ‘Krasnoyaruzhskaya 2’ (Medicago varia), ‘Kazatsky’ (Trifolium pratense), ‘Olshanka’ and ‘Ivica’ (Festuca arundinacea), ‘Streletsky’ and ‘Stepnyak’ (Lolium perenne)) obtained using local genetic material were studied. All varieties showed their resistance in agro-ecosystems with active development of linear erosion in the forest-steppe and steppe zones. Projective cover on watercourses in the steppe zone in all variants of experience was on average 83,4 %, in the forest-steppe zone - 86,3 %. In the third year of the tests on permanently irrigated watercourses in the steppe zone, the share of cereal and legume grass species was quite high and varied from 88 % in the variant M. varia + Onobrychis arenaria to 92 % in the variants M. varia + Bromopsis inermis and O. arenaria. In the forest-steppe zone, the share of cereal and legume grass species varied from 86 % in the variant L. perenne to 94 % in the variant L. perenne + B. inermis.


2021 ◽  
Vol 26 (2) ◽  
pp. 427-437
Author(s):  
Rafael Quirino Moreira ◽  
Vanessa Do Nascimento Ramos ◽  
Adriane Suzin ◽  
Diego Garcia Ramirez ◽  
Paulo Ricardo De Oliveira Roth ◽  
...  

We evaluated the role of communities of small mammals from three distinct areas in a region of Cerrado mixed with Atlantic Forest remains for maintenance of tick fauna. Thirty-nine marsupials (Gracilinanus agilis, n = 34; Marmosa paraguaiana, n = 4; Didelphis albiventris, n = 1) and 33 rodents (Oecomys cleberi, n = 10; Nectomys squamipes, n = 4; Calomys tener, n = 4; Hylaeamys megacephalus, n = 4; Akodon sp., n = 3; Rattus rattus, n = 3; Cerradomys subflavus, n = 2; Mus musculus, n = 2; Rhipidomys macrurus, n = 1) were captured. Solely G. agilis and the four rodent species (N. squamipes, R. macrurus, C. subflavus and Akodon sp.) were infested. Four tick species were collected (Amblyomma dubitatum, Amblyomma sculptum, Ixodes loricatus and Ornithodoros mimon). A. dubitatum was the most abundant tick species on hosts. Capture success was higher in the dry season, but the infestation was similar in both seasons. Forested habitats, particularly riparian forests, resulted in higher number of hosts and ticks collected (from hosts and from vegetation), compared to pastures and anthropized sites. The association between C. subflavus and I. loricatus and between A. dubitatum and N. squamipes observed here is the first recorded in Cerrado biome. Areas with more patches of forest, including the Atlantic Forest fragments, tend to present a richest community of small mammals and associated ticks.


2021 ◽  
Vol 51 (1) ◽  
pp. 25-32
Author(s):  
A. A. Malyuga ◽  
N. S. Chulikova

Long-term studies (2014–2019) of the population dynamics of the fungus Rhizoctonia solani Küch. were carried out in the soil on the Purple Majesty, Vitelotte and Fioletovy potato varieties and preceding crops (potatoes, oats and tendergreen). The study was carried out in Novosibirsk region in the soil and climatic conditions typical of the forest-steppe zone of Western Siberia. To study the peculiarities of R. solani fungus population dynamics in potato plantations, soil samples were taken from under the plants during the entire growing season. The accumulation of rhizoctonia propagules in the soil was determined using the method of multiple soil pellets. The difference in the amount and rate of accumulation of the fungus R. solani on different varieties, as well as the influence of previous crops on this process, was established. Two peaks of the fungus accumulation were observed on the Purple Majesty variety: the first (48.7 propagules/100 g of soil) – during the full germination period, the second (57.2 propagules/100 g of soil) – at the end of the crop maturation phase. One peak was observed in the population dynamics of the fungus on Vitelotte and Fioletovy varieties, at the end of the ripening period (59.0 and 49.1 propagules/100 g soil, respectively). The smallest amount of R. solani fungus in the soil on average during the growing season was noted on the Fioletovy variety – 33.3 propagules/100 g of soil. In the Purple Majesty and Vitelotte varieties, this figure was 41.5 and 40.4 propagules/100 g of soil, respectively. When potato variety Agata was cultivated as monoculture, there was a rapid and significant accumulation of the fungus R. solani in the soil (from 34.6 to 126.8 propagules/100 g of soil). When this variety was cultivated following tendergreen or oats, the amount of the pathogen varied to a lesser extent (25.1–52.2 and 19.8–41.0 propagules/100 g of soil, respectively). No sharp increases in the number of propagative structures of the phytopathogen in the soil were noted.


2021 ◽  
pp. 38-53
Author(s):  
O.G. Golubtsov ◽  
◽  
L.Yu. Sorokina ◽  
L.M. Tymuliak ◽  
V.M. Chekhniy ◽  
...  

The purpose of the publication is to present the results of the study of anthropogenic changes in the landscapes of the Forest-Steppe zone of Ukraine, implemented by assessing the indicators of landscapes anthropogenic transformation, their diversity and fragmentation. The basic research methods are methods of geospatial GIS analysis and decoding of remote sensing data of the Earth, geoinformation mapping. According to the indicators of anthropogenic transformation of landscapes at the level of physical-geographical regions and districts of the Forest-Steppe zone, the features of changes for the period 1992-2018 are determined. The results of assessment of anthropogenic changes in forest-steppe landscapes of Ukraine show that in 1992 as well as in 2018 the vast majority of the landscapes of the territory are strongly and excessively transformed by anthropogenic activity. Such patterns persist, despite the fact that during the analyzed period in part of the investigated area there is a certain decrease in anthropogenic pressure on landscapes. The regular relations between the indicators of anthropic landscape diversity and fragmentation of landscapes are determined, which corroborates to their certain conditionality by the degree and nature of anthropogenic transformation of the territory. The novelty of the study are the proposed methods of spatial and temporal changes in landscapes estimating and identifying such changes in landscapes at the level of physical and geographical regions for the period 1992-2018 and revealing trends in the structure of land use, especially agricultural lands, forests, built-up territories as the leading types of land use in the Forest-Steppe zone of Ukraine.


Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 763
Author(s):  
Andrey Novoselov ◽  
Alexandr Konstantinov ◽  
Artem Lim ◽  
Katja Goetschl ◽  
Sergey Loiko ◽  
...  

The formation of Mg-rich carbonates in continental lakes throughout the world is highly relevant to irreversible CO2 sequestration and the reconstruction of paleo-sedimentary environments. Here, preliminary results on Mg-rich carbonate formation at the coastal zone of Lake Vtoroe Zasechnoe, representing the Setovskiye group of water bodies located in the forest-steppe zone of Southwest Western Siberia, are reported. The Setovskiye lakes are Cl−–Na+–(SO42−) type, alkaline, and medium or highly saline. The results of microscopic and mineralogical studies of microbialites from shallow coastal waters of Lake Vtoroe Zasechnoe demonstrated that Mg in the studied lake was precipitated in the form of hydrous Mg carbonates, which occur as radially divergent crystals that form clusters in a dumbbell or star shape. It is possible that hydrous Mg carbonate forms due to the mineralization of exopolymeric substances (EPS) around bacterial cells within the algal mats. Therefore, the Vtoroe Zasechnoe Lake represents a rare case of Mg-carbonates formation under contemporary lacustrine conditions. Further research on this, as well as other lakes of Setovskiye group, is needed for a better understanding of the possible role of biomineralization and abiotic mechanisms, such as winter freezing and solute concentration, in the formation of authigenic Mg carbonate in modern aquatic environments.


2020 ◽  
Vol 161 ◽  
pp. 01102
Author(s):  
Alfia Razina

Energy-saving technologies of wheat cultivation limit the buffer role of the agrotechnical method in reducing the spread of root rot. This situation calls for using increased volumes of pesticides in order to decrease harvest losses arising from actions of harmful organisms, which does not allow to produce organic food.Considering this, evaluation of the efficiency of agrotechnical methods of cultivating spring wheat aimed at enhancing phytosanitary conditions of crops is very important. The goal of our work was to evaluate the role of predecessors, methods of soil preparation,organic fertilizers, new varieties of spring wheat, and the timing of planting in limiting the spread and reducing the harmfulness of root rot. Our study has been conducted in the forest-steppe zone of Eastern Siberia. We have established that green manure in crop rotationandfallow arable land with introduction of 30 t/ha of organic manure fertilizer with a disc harrow to a depth of 10–12 cmreduce the spread and severity of root rot and increase wheat yields. In the plantings of the new variety of spring wheat Marsianka, the spread of the disease was reliably less,and the yield was higher compared to the control variety Tulunskaya 11. The optimal planting date for the average of two years was May 25, the crops planted then compared to those planted on May 30 were 9.4% less affected by the disease and gave a reliable increase in the harvest of 0.15 tons/ha. Our studies have shown that during production of organic wheat we can limit the spread andharmfulness of root rot withagrotechnical methods.


2021 ◽  
Vol 101 (2) ◽  
pp. 265-272
Author(s):  
M. I. Kormilitsyna ◽  
E. I. Korenberg ◽  
T. V. Mikhaylova ◽  
Yu. V. Kovalevskii ◽  
A. V. Amirkhanyan ◽  
...  

2012 ◽  
Vol 81 (2) ◽  
pp. 97-102 ◽  
Author(s):  
František Treml ◽  
Jiří Nepeřený ◽  
Eva Jánová ◽  
Hana Banďouchová ◽  
Jiří Pikula

A total of 2,195 small mammals belonging to 8 species were captured in different districts of South Moravia, Czech Republic, and examined for antibodies against leptospires in the period from 2004 to 2008. Positive specimens amounting to 173 (9%) were found annually in five species of rodents such as Apodemus sp., Clethrionomys glareolus, Microtus arvalis, Mus musculus and Rattus norvegicus. The recognised leptospiral serotypes included L. grippotyphosa, L. bulgarica, L. sejroe and L. icterohaemorrhagiae/copenhageni. The highest prevalence of antibodies was against the L. grippotyphosa serotype (92.8%). Reactions with other serotypes of leptospires were exceptional. Reactions with L. bulgarica antigen were only due to coagglutination with L. grippotyphosa leptospires. The titres ranged from 100 to 12,800. However, lower values up to the titre of 800 predominated in 151 cases (83.4%). There were non-significant sex differences in seroprevalence with 8.1% and 7.6% prevalence in males and females, respectively. Marked differences were, however, found in seroprevalence of juveniles and adults with 3.3% and 10.2%, respectively. Adult males and females were seropositive in 10.9% and 9.5%, respectively; juveniles were seropositive only in 3.0% and 3.7%. The highest percentage of specimens (43.6%) was examined during July and August. The summer seroprevalence of 10.9% was higher than in spring and autumn. Our results revealed the persistence of both natural and synanthropic nidi of leptospirosis in the region under study and demonstrated epidemiological implications regarding health protection of animals and humans.


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