


Vol 9, No 6 (2016)
- Year: 2016
- Articles: 14
- URL: https://journals.rcsi.science/1995-4255/issue/view/12550
Article
Spatial distribution of some alien plants across a restricted mountainous area
Abstract
Plant invasion of natural ecosystems is one of the most serious ecological crises of our time. The invasive plants are one of the causes for native species decline and ecosystem degradation. This study tries to answer the question whether studied mountainous area is relatively free of plant invasions. We also try to provide a clue about the possible causes for the current invasion state of the studied territory. We used direct ordination, correlation and multiple regression techniques coupled with different statistical tests to describe the current invasion pattern of the studied vegetation. We found that the most invaded vegetation types are lowelevational mixed xerophilous and subxerophilous oak forests and pine plantations. The open subalpine communities are relatively uninvaded. Alien species richness is highest in the xeric habitats at low elevations and in the mesic ones at higher elevations. The common beech forests in the mesic habitats at low to middle elevations are almost completely free of invasion. The leading factors, driving invasion processes in the area are thought to be the anthropogenic and natural disturbances, placed in the context of main local environmental gradients like elevation, habitat moisture and slope inclination. Understanding the factors that drive mountain vegetation invasion helps us taking timely actions to prevent further degradation of precious natural habitats around the globe.



Assessment of the contribution of climate change and human activities to desertification in Northern Kordofan-Province, Sudan using net primary productivity as an indicator
Abstract
Using net primary productivity (NPP) as an indicator to desertification driving factor and expansions is one of the importance tools in the assessment of the contribution of climate change and human activity in desertification. In this study we used three types of net primary productivity; the actual NPP, Potential NPP and HNPP (human appropriation of NPP) to discriminate the relative role of climate change and human activities in desertification from 2000 to 2008 in Northern Kordofan province-Sudan. The results showed, 63.75% of the study area experienced desertification expansion. Within which, 67.32% was induced by Human activities compared with 32.03% caused by climate change and 0.65% caused by a combination of the two factors. By contrast, climate change is the dominant factor of desertification reversion, 2.3% of desertification reversion caused by human activities compared with 97.7% induced by climate change and there isn’t interaction between climate change and human activities in reversion area. The largest area of expansion and reversion occurred in northeast and western parts of the study area respectively. We developed two propositions in the study area. First, the desertification expansion was induced by human activities, whereas desertification reversion was induced by climate change as typified in north south part, central part and western part. Second, both desertification expansion and reversion was induced by climate change as typified in northeast part of study area.



Natural zonality in the distribution of arthropods, birds, and vascular plants in the area of the Lower Ob region and Yamal Peninsula
Abstract
This paper is devoted to an analysis of the pattern of zonal distribution of mesofaunal arthropods, birds, and vascular plants in the area from northern taiga forests to arctic tunrdas of the Yamal Peninsula by the gradient of summer air temperatures. The latitudinal dynamics of northern ecosystems determines differences in the number of plant species that have a direct effect on the species richness and abundance of invertebrates and an indirect one through invertebrates on the same indices of birds. Breaks in continuity marking the natural boundaries where the components of arctic communities become boreal have been found in the changes of species diversity.



Forest cover classification and geoinformation modeling of forest regeneration dynamics (Based on the example of the southern part of near-Yenisei Siberia)
Abstract
An automated conjugate classification of forest growing conditions and forest vegetation has been developed based on the example of the southern part of Yenisei Siberia; maps of potential forest growing conditions and forest-cover regeneration dynamics have been constructed on the basis of the automated recognition of remote sensing data and a system of conjugate analysis of dissimilar data in GIS. The proposed approach makes it possible to promptly create and update forest cover maps, which is particularly important for the vast taiga regions of Siberia.



Satellite monitoring of the state of forest vegetation after fire impacts in the Zabaikal region
Abstract
Based on the MODIS radiometer data, the level of disturbance of forest lands by fires has been estimated for southwestern areas of the Zabaikal region. A combined analysis of vegetation indices calculated by measuring reflected radiation in the near and mid-infrared wave ranges and the data of on-ground studies allowed us to identify sites with successful and poor reforestation. Based on the instrumental data, it is found that repeated fires prevent successful reforestation. An analysis of seasonal dynamics indicates that summer fires result in greater damages of forest vegetation than those caused by spring fires. Larch stands prevailing in the region cover the largest portion of fire-disturbed lands (and the largest area, where reforestation processes are hampered), while pine and deciduous stands are characterized by a higher frequency of fires.



Spatial and temporal dynamics of Siberian silk moth large-scale outbreak in dark-needle coniferous tree stands in Altai
Abstract
The spatial and temporal dynamics of fir stands damage caused by a large-scale outbreak of the Siberian silk moth (Dendrolimus sibiricus Tschetv.) in the Altai Mountains has been studied using remote sensing and GIS methods. It is ascertained that forest damages are dissimilar relative to the surface features. The pest outbreak initially occurred on the southwest slopes with mean values of 10° and elevation of 400 m asl. The damages further extended both upward and downward, involving slopes of high steepness and the eastern exposure. The total area of the dead stands comprised 6000 ha, 45% of which were lost due to secondary pest (xylophagous insects) attacks. It is indicated that the use of remote sensing made it possible to determine the beginning of a pest outbreak with one-decade precision. The Siberian silk moth large-scale outbreak occurred against an increase in air temperatures, a decrease in precipitation, and a reduction in late frosts. The tree plants weakened by the Siberian silk moth and water stress were affected by xylophagous insect attacks. The observed and predicted warming and climate aridity increase will facilitate Siberian silk moth outbreaks both within its range and northward of the current margins of the range.



Assessment of climatic limits of needle cast–affected area under climate change in Central Siberia
Abstract
The relationships between climate (January and July temperatures, annual precipitation, and a relative moisture index) and the number of foci and intensity of the needle cast disease caused by fungi from the genus Lophodermium Chevall. in the Scots pine nurseries and provenance trials in Krasnoyarsk krai have been studied using multivariate statistics methods. It is found that peaks in the disease occurrence are related to the warm and humid weather conditions. Bioclimatic models of the needle cast ranges have been built using the climate variables; the spatial dynamics of the disease occurrence have been projected under various scenarios of climate warming over the 21st century. Model experiments have shown that the needle cast disease would shift northwards into the new regions in Krasnoyarsk krai, where the phytopathogen has not yet been registered in the nurseries. The largest forest areas exposed to needle cast disease are predicted to be at a high risk of outbreaks by 2020 under moderate climate warming. With a significant warming trend by 2080, potential risk areas will be reduced, because the pine expansion into the permafrost zone should be limited by slow thawing of its active layer.



Ecological and molecular genetic features of Ixodes persulcatus and I. pavlovskyi ticks in Southern West Siberia
Abstract
Ixodiae ticks have been counted and sampled in six distant locations within the Altai-Sayan Mountain Area and northern forest steppe in 2012. In total, 1829 individuals of I. persulcatus and 719 of I. pavlovskyi ticks were collected by flagging. I. persulcatus is found in all six examined locations and I. pavlovskyi is found in Western Altai, Northeastern Altai, and Northern Altai, as well as in forest parks near Akademgorodok of Novosibirsk. In total, 16S rRNA and COI sequences have been determined in 144 and 164 I. persulcatus individuals, as well as in 60 and 55 I. pavlovskyi. Selectively equivalent mutant forms are present in I. pavlovskyi populations of Northeastern Altai and Northern Altai. The hydrothermal regime in the forest parks near Novosibirsk is optimal for the I. pavlovskyi ticks. These ticks have recently colonized the forest parks near Novosibirsk and therefore are genetically close to I. pavloskyi from the Altai–Sayan Mountain Area populations.



Specific features of taxonomic organization of cyanobacterial–algal flora in extreme habitats as reflection of different sucfcession models
Abstract
We have revealed 75 species (78 species and intraspecies taxa) of algae and cyanobacteria that first colonized the substrates in different regions of Russia (Yano-Oimyakon Upland in the eastern part of Asian Russia and Western Siberia). An analysis of the data shows that the development of substrates (rocks and sandy ground) differs. They may be considered specific natural models of the development of autogenic lithoand psammosuccessions.



Phytoplankton structure in the White Sea after summer bloom: Spatial variability in relation to hydrophysical conditions
Abstract
The species composition and phytoplankton biomass, concentrations of chlorophyll “a” (Chl) and nutrients, concurrent hydrophysical conditions were studied in the south part of the White Sea in July 10–15, 2012 during chlorophyll “a” decrease after summer peak. The water column stability varied, the concentration of dissolved silicon in upper mixed layer was closed to the range favorable for diatoms with exception of areas of intensive tide mixing and areas influenced by waters of Severnaya Dvina River. In surface layer the dinoflagellates dominated excepting of areas with intensive tide mixing where diatoms prevailed. Diatoms provided major contribution to biomass in different stations above, in and under pycnocline and in deep waters out of photic zone. Structural analysis has revealed three phytoplankton communities that corresponded to different depths: communities of photic zone, intermediate and deep layers. Extension of layers inhabited by different communities depended on water column stability and on genesis of water masses. Integrated values of phytoplankton biomass and Chl varied from 250 to 1188 mg С/m2, and from 22 to 51 mg/m2, correspondently.



Spatial–typological structure and organization of the winter and early spring bird assemblages on the northern macroslope of the Kyrgyz Ridge (Tien Shan)
Abstract
The hierarchical classification was drafted and the spatial–typological structure of the winter and pre-spring bird assemblages is described for the northern macroslope of the Kyrgyz Ridge. The descriptiveness of the classification and structural representations, as well as an evaluation of the variability of communities in relation to environmental factors, are determined using a linear approximation of quality, structure, and organization of bird assemblages in these periods. In general, the heterogeneity of bird communities on the northern slope of Kyrgyz Ridge in winter and early spring periods is associated with the variability in heat and humidity, as well as the presence of built-up areas and single-crop agriculture. In winter, changes in avifauna are more gradual than in the early spring period.



Survival and growth rates of pups in common vole (Microtus arvalis) litters depending on the presence of sire
Abstract
Two groups of litters obtained from individuals captured in natural environments have been monitored under laboratory conditions. The females of one group reared the offspring in the absence of sires; the litters of the other group are raised by both parents. It is ascertained that the presence of sires, especially those who are characterized by higher levels of aggression, has a negative effect on the survival and growth rates of the pups. Therefore, the reproductive success of common vole males can decrease if they enter the family-group composition and depends on the specificity of their behavior, first and foremost, an inclination toward exhibiting aggression.



Effect of plants on processes of methane cycle in bottom deposits and soil rhizosphere
Abstract
This article contains an analysis and generalization of published data and our own data on the effect of living plants on the formation, oxidation, and concentration of methane in water and boggy ecosystems. Plants regulate the physicochemical conditions in soil rhizosphere and bottom deposits, the number and activity of microorganisms, and methane emission into the atmosphere. The data of theoretic–experimental investigations into the mechanism of aerobic nonmicrobiological methane formation in phylosphere of plants are also discussed.



Heavy metals in phyto- and zooplankton of Lake Kenon (Transbaikalia)
Abstract
The content and accumulation of particular heavy metals in phyto- and zooplankyon from the technogenically transformed Lake Kenon (Chita, Transbaikalia) have been studied. Algae contains the highest concentrations of Zn and Sr. Zooplankton is characterized by concentrations of Ni, Cu, Cd, and Hg either below or equivalent to those known for other water bodies. It has been shown that the distribution of heavy metals in the studied water body is differentiated. Their greatest concentration has been registered in the plankton of technogenically contaminated sites—CHPP and Oil Tank Farm.


