scholarly journals Patterns in steppe meadow vegetation at the border of Forest-steppe and Steppe zones of the Southern Ural

2020 ◽  
Vol 9 (3) ◽  
pp. 93-99
Author(s):  
Nazar N. Nazarenko ◽  
Aleksandr V. Malaev ◽  
Alla V. Pirozhenkova ◽  
Natalya A. Bayda

The patterns (mosaicity) in steppe meadow vegetation were characterized at the border of Forest-steppe and Steppe zones of the Southern Ural by hierarchical continuum concept theory for Troitskiy state natural complex preserve example. It has been established that the discordant natural region bring about mosaicity destruction micro-patterns are fuzzy, parcels are not formed and coenotics (12,0 m) level is identified only. The steppe meadow vegetation is characterized by coenotic level continuum coenotic patterns have almost identical dominant and co-dominant species composition, phytochorologic units form combination of four meadow grasses with middle and weak contagious spatial distribution and most species have random spatial distribution. But the steppe meadow biotopes are characterized by specifics of abiotic factors. The significant factors, influencing coenotic patterns and biotopes of steppe meadow, are soil calcium and nitrogen regime, soil aeration, moistening and its variability.

Author(s):  
Nazar N. Nazarenko ◽  
◽  
Aleksandr V. Malaev ◽  
Alla V. Pirozhenkova ◽  
Natalya A. Bayda ◽  
...  

The patterns (mosaicity) in natural halophytic grasslands at the border of Forest-steppe and Steppe zones of South Ural were characterized by the hierarchical continuum concept theory for the Troitskiy state natural complex preserve example. It was established, that the grass canopy is fragmented by salinization impact, the individual’s random distribution is typical of halophytes and salttolerant steppe species form patterns. Only the micro-patterns (0,8 m) level is statistically significant, parcels (8 m) and coenotics (12 m) are fuzzy and fragmentation of mosaicity is observed. There are two coenotics series defined for parcels – halophytic and steppe, relating to the distribution of halophytes and steppe grasses respectively. There is clear coenosis. Separation is observed by phytodiversity and biotopes descriptions. The intracoenotic interactions between species, soil moistening variability, soil aeration and acidity (alkalinity) and soil mineralization increase (decrease) are significant for parcels and coenosis forming.


2018 ◽  
Vol 7 (4) ◽  
pp. 85-93
Author(s):  
Nazar Nikolayevich Nazarenko ◽  
Yevgeny Dmitrievich Perlov

The patterns (mosaicity) in grassland vegetation of Southern Ural for Bredinskiy state natural wildlife preserve example have been characterized by a hierarchical continuum concept theory. The multispecies patterns identification has been done by blocks and principal components methods and hierarchical patterns evaluation - by multivariate statistics (Cluster, Discriminant Analysis and Non-Metric Multidimensional Scaling) and biotopes phytoindication. It has been established that there are two patterns levels - parcels (6,0 m) and coenotics (11,0 m) in grassland vegetation. Thus, hierarchical continuum in steppe grassland vegetation of Southern Ural has been confirmed by multivariate statistics. Detected patterns have been classified and its phytochorologic unit has been identified. For patterns informative and dominant species have been also detected. It has been demonstrated that species dominance and its significance in patterns depend upon mosaicity levels. Some non-uniformly scaled ecological factors have been identified for patterns continuum. The principal significance for steppe grassland parcels matter coenotic and phytodiversity factors, for coenotics patterns forming matter abiotic factors too. For Bredinskiy state natural wildlife preserve principal abiotic factors steppe grassland patterns forming are (by decrease) soil calcium regime, soil nitrogen regime, soil acidity, soil mineralization and aeration.


2020 ◽  
Vol 9 (2) ◽  
pp. 91-97
Author(s):  
Nazar N. Nazarenko ◽  
Aleksandr V. Malaev ◽  
Alla V. Pirozhenkova ◽  
Natalya A. Bayda

The patterns (mosaicity) in the northern type of Southern Ural steppe vegetation were characterized by a hierarchical continuum concept theory for Troitsky State Natural Complex Preserve example. Multispecies patterns have been identified by blocks and principal components methods while a hierarchical patterns evaluation by multivariate statistics (Cluster, Discriminant Analysis and Non-Metric Multidimensional Scaling) and biotopes phytoindication. It has been established that three pattern levels micro-patterns (0,8 and 1,8 m), parcels (6,0 m) and coenotics (11,0 m) are significantly identified in steppe vegetation. The two last levels correspond to levels specified for the southern type of Southern Ural steppe vegetation earlier. The authors have demonstrated that parcel and coenotic patterns are identified as ratio of four species abundance: Stipa lessingiana, S. pennata, S. tirsa and Festuca valesiaca. For natural and undisturbed steppe associations informative species are non-dominants or edificators. Vegetation plot size and the location in phytocatena can be determinative for floristic composition, phytodiversity indexes and syntaxon detection. There are several non-uniformly scaled factors of mosaicity identification. The most significant ones are coenotic interactions among species. Soil nitrogen regime and soil calcium regimes, soil moistening, aeration and acidity are significant for abiotic factors.


1995 ◽  
pp. 3-21
Author(s):  
S. S. Kholod

One of the most difficult tasks in large-scale vegetation mapping is the clarification of mechanisms of the internal integration of vegetation cover territorial units. Traditional way of searching such mechanisms is the study of ecological factors controlling the space heterogeneity of vegetation cover. In essence, this is autecological analysis of vegetation. We propose another way of searching the mechanisms of territorial integration of vegetation. It is connected with intracoenotic interrelation, in particular, with the changing role of edificator synusium in a community along the altitudinal gradient. This way of searching is illustrated in the model-plot in subarctic tundra of Central Chukotka. Our further suggestion concerns the way of depicting these mechanisms on large-scale vegetation map. As a model object we chose the catena, that is the landscape formation including all geomorphjc positions of a slope, joint by the process of moving the material down the slope. The process of peneplanation of a mountain system for a long geological time favours to the levelling the lower (accumulative) parts of slopes. The colonization of these parts of the slope by the vegetation variants, corresponding to the lowest part of catena is the result of peneplanation. Vegetation of this part of catena makes a certain biogeocoenotic work which is the levelling of the small infralandscape limits and of the boundaries in vegetation cover. This process we name as the continualization on catena. In this process the variants of vegetation in the lower part of catena are being broken into separate synusiums. This is the process of decumbation of layers described by V. B. Sochava. Up to the slope the edificator power of the shrub synusiums sharply decreases. Moss and herb synusium have "to seek" the habitats similar to those under the shrub canopy. The competition between the synusium arises resulting in arrangement of a certain spatial assemblage of vegetation cover elements. In such assemblage the position of each element is determined by both biotic (interrelation with other coenotic elements) and abiotic (presence of appropriate habitats) factors. Taking into account the biogeocoenotic character of the process of continualization on catena we name such spatial assemblage an exolutionary-biogeocoenotic series. The space within each evolutionary-biogeocoenotic series is divided by ecological barriers into some functional zones. In each of the such zones the struggle between synusiums has its individual expression and direction. In the start zone of catena (extensive pediment) the interrelations of synusiums and layers control the mutual spatial arrangement of these elements at the largest extent. Here, as a rule, there predominate edificator synusiums of low and dwarfshrubs. In the first order limit zone (the bend of pediment to the above part of the slope) one-species herb and moss synusiums, oftenly substituting each other in similar habitats, get prevalence. In the zone of active colonization of slope (denudation slope) the coenotic factor has the least role in the spatial distribution of the vegetation cover elements. In particular, phytocoenotic interactions take place only within separate microcoenoses of herbs, mosses and lichens. In the zone of the attenuation of continualization process (the upper most parts of slope, crests) phytocoenotic interactions are almost absent and the spatial distribution of vegetation cover elements depends exclusively on the abiotic factors. The principal scheme of the distribution of vegetation cover elements and the disposition of functional zones on catena are shown on block-diagram (fig. 1).


Author(s):  
Roger Moussa ◽  
Bruno Cheviron

Floods are the highest-impact natural disasters. In agricultural basins, anthropogenic features are significant factors in controlling flood and erosion. A hydrological-hydraulic-erosion diagnosis is necessary in order to choose the most relevant action zones and to make recommendations for alternative land uses and cultivation practices in order to control and reduce floods and erosion. This chapter first aims to provide an overview of the flow processes represented in the various possible choices of model structure and refinement. It then focuses on the impact of the spatial distribution and temporal variation of hydrological soil properties in farmed basins, representing their effects on the modelled water and sediment flows. Research challenges and leads are then tackled, trying to identify the conditions in which sufficient adequacy exists between site data and modelling strategies.


2001 ◽  
Vol 22 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Sylvie Thurnheer ◽  
Heinz-Ulrich Reyer

AbstractPredictions about population and community dynamics are usually based on lab experiments. Because the results are difficult to transfer to natural conditions, the major purpose of this study was to test the effects of biotic and abiotic factors on tadpole populations in a natural environment. We stocked six ponds, created the previous year, with known numbers of Rana esculenta and R. lessonae tadpoles and followed their development over several months. When compared among ponds, tadpole density correlated positively with the nitrate:phosphate ratio. This suggests that water chemistry may have affected survival, either directly or indirectly via productivity. Within ponds, both species showed a clear preference for the shallow zone. This behavior probably reflects a preference for warm water close to the surface, rather than avoidance of predators, because relative densities of odonates also increased from deep to shallow zones. This study is one of few that not only considers the distribution of the anuran tadpoles but the distribution of their predators as well.


bionature ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Muhammad Richsan Yamin ◽  
Siti Annisaa'ul Kariimah ◽  
Nadya Rizky Nuzul Ramadhanti ◽  
Intan Ayu Idha Wulandari

Abstract. The purpose of this research were to (1) analyse the temporal and spatial distribution of arthropods in the cassava and eggplant agroecosystem areas. (2) Analysing the temporal and spatial distribution of arthropods in the maize agroecosystem. This research was divided into 2 stations,  the first station which is near the trail in the eggplant and corn agroecosystem, while for the second station on the corn agroecosystem, the two research locations are in Maccorawalie Village, Watang Sawitto District, Pinrang Regency, South Sulawesi. This research use the analytical method to analyse the observations and also identify the families of each arthropod found, then count the number of arthropods in each species and measure the diversity and abundance of each wild plant found at station 1 and station 2 in the morning and afternoon. The translation of the results obtained from the results of data collection at two stations in two data collection times (morning and afternoon) in the day, where the morning is 06.00-8.00 WITA Zone, while in the afternoon at 16.00-17.30 WITA zone. This is due to abiotic factors such as temperature and humidity, where the temperature in the morning is 23°C with 92% humidity, while the afternoon temperature is 25°C with 77% humidity. Arthropods have a different temporal distribution because this is related to the biological clock in each Arthropod. Biological clock allows Arthropods to determine when to work and rest. The existence of a rhythm in insects resulted in the division of two living groups, known as diurnal (active during the day) and nocturnal. Abiotic factors in the form of light intensity, temperature and humidity, affect the activity patterns of insects that have a certain temperature range, light intensity and humidity in Maccorawalie Village, Watang Sawitto District, Pinrang Regency.Keywords: temporal distribution, spatial distribution, arthropods, agroecosystem.


2019 ◽  
Vol 24 ◽  
pp. 49-52
Author(s):  
L. A. Vilchynska ◽  
A. S. Gorash

Aim. To compare the new variety of buckwheat Kamianchanka by individual indicators of suitability for distribution, difference, uniformity and stability with a conditional national variety-standard. Methods. The creation, study, evaluation, reproduction and transfer to the State trials of a new variety was carried out in accordance with the generally accepted methods of state trials. Results. The article presents the main identification indicators of the Kamianchanka buckwheat variety, created in the Podilskyi State Agrarian Engineering University. In terms of the suitability of the variety for distribution, difference, uniformity and stability, the Kamianchanka buckwheat variety exceeds the average yield of the varieties that have passed state registration in the previous five years in the Forest-Steppe Zone. The average yield of the new variety was higher than the conventional standard by 1.7 and 3.7 c / ha, or by 9.3 and 19.6%, respectively. Plant height varied from 73 to 156 cm and was on average 15 cm higher than the standard. The mass of 1000 seeds varied from 25.4-35 g and was higher in the Forest-steppe zone by 3.7-5 g (11.4-11.7%) compared with the conventional standard. A new variety of buckwheat Kamenchanka is sufficiently resistant to biotic and abiotic factors, suitable for cultivation in intensive technologies and mechanized harvesting. Сonclusions. A new variety of buckwheat Kamianchanka is listed in the Register of Plant Varieties of Ukraine for 2019. Recommended for growing farms of various forms of ownership. Keywords: buckwheat, yield, qualitative parameters, state test.


2018 ◽  
Author(s):  
John H. Boyle ◽  
Dino Martins ◽  
Paul M. Musili ◽  
Naomi E. Pierce

AbstractThe association between the African ant plant, Vachellia drepanolobium, and the ants that inhabit it has provided insight into the boundaries between mutualism and parasitism, the response of symbioses to environmental perturbations, and the ecology of species coexistence. We use a landscape genomics approach at sites sampled throughout the range of this system in Kenya to investigate the demographics and genetic structure of the different partners in the association. We find that different species of ant associates of V. drepanolobium show striking differences in their spatial distribution throughout Kenya, and these differences are only partly correlated with abiotic factors. A comparison of the population structure of the host plant and its three obligately arboreal ant symbionts, Crematogaster mimosae, Crematogaster nigriceps, and Tetraponera penzigi, shows that the ants exhibit somewhat similar patterns of structure throughout each of their respective ranges, but that this does not correlate in any clear way with the respective genetic structure of the populations of their host plants. A lack of evidence for local coadaptation in this system suggests that all partners have evolved to cope with a wide variety of biotic and abiotic conditions.


Sign in / Sign up

Export Citation Format

Share Document