System analysis of biogeocenoses of the Yamal Peninsula: Simulation of the impact of large-herd reindeer breeding on vegetation

The systemic approach based mainly on computer simulation has been used to assess the dynamics of ecosystems of the Yamal Peninsula, which have been exposed to the impact of numerous reindeer herds because of extensive development of reindeer breeding during the past decades. This type of development has been demonstrated to result in degradation of vegetation, whose profound changes preclude further development of reindeer breeding in the same way. The current situation requires major amendments to the ethnic-cultural and economic policy in the region.     

The Holocene dynamics of vegetation and climatic conditions on the eastern slope of the Subpolar Urals

Changes in the vegetation and climatic conditions on the eastern slope of the Subpolar Urals over the past 10000 years have been reconstructed on the basis of integrated palynological, botanical, and radiocarbon analysis of material from two sections of peat deposits in the floodplains of the Lyapin and Man’ya rivers (the Severnaya Sos’va basin). The dynamics of regional vegetation have been traced: from the herb–shrub tundra in the late postglacial time to the spruce–larch forest–tundra and sparse larch–birch–spruce stands in the Early Holocene, to birch–pine–spruce forests with an admixture of fir in the Middle Holocene, and to northern taiga forests with dominance of Scots pine and Siberian stone pine (similar to present-day forests) in the Late Holocene. The results show that the northern taiga zone of the study region in the period between approximately 5500 and 2500 years BP was occupied by forests of middle and southern taiga facies, as the climate was significantly warmer than it is today.     

First data on the Middle to Late Holocene dynamics of vegetation in the Upper Kama region

A detailed palynological record and the results of radiocarbon dating of sediments from the Dedyukhinskii floodplain massif in the vicinity of Lake Chashkinskoe (the Upper Kama region; 59°23′ N, 56°34.5′ E) have been used to reconstruct basic stages in the Middle to Late Holocene dynamics of vegetation. The results show that in the Atlantic period broadleaf tree species played a secondary role in forest formations of taiga and subtaiga types. Broadleaf–conifer forests became dominant in the Subboreal period, with fir widely spreading in the forests during its second half. During the Subatlantic period, forest formations acquired their recent taiga character.     

Climate changes and overstory recruitment of larch at the northern timberline in the Yamal Peninsula

Studies on overstory recruitment of the Siberian larch (Larix sibirica Ledeb.) in open larch forests depending on the time of seedling establishment (1880–1980) have been performed in the northern timberline ecotone on the Yamal Peninsula. Two periods of active larch establishment have been revealed: from 1900 to 1935 and from 1950 to 1970. A comparison of these data with the results of instrumental observations on temperature and precipitation has shown that the overstory recruitment of larch in valleys of northern rivers is largely dependent on July air temperatures in the first years of tree life, when seedlings grow 10–20 cm high.     

Holocene dynamics of invertebrate fauna in the littoral zone of Adak,the Aleutian Islands,according to archaeozoological data

Studies on invertebrate remains from the cultural layer of an ancient Aleut settlement on Adak Island have shown that the faunistic composition of invertebrates in the study area had not changed significantly during the Late Holocene. The traditional mode of natural resource use by the ancient Aleuts had no impact on the abundance of valuable species and biodiversity in general. Changes in the temperature regime were found to have taken place in the history of deposit formation. The period from the 8th to the mid-11th century was relatively cold. Climate warming took place between the mid-11th and the mid-12th centuries and between the mid-16th and the 19th centuries, with an intervening cooling period (from the mid-12th to the mid-16th century). This cooling was most distinct between the 15th and the mid-16th centuries.     

Reconstruction of the Holocene vegetation in the central Negev Desert,Israel, on the basis of palynological data on the Atzmaut zoogenic deposit

Zoogenic deposits are among a few promising sources of information on the history of arid ecosystems. To reconstruct the former vegetation of the Negev Desert, we performed palynological analysis of the Atzmaut zoogenic deposit that had been formed over the past 6000 years. The results made it possible to reveal seasonality in the use of this rockshelter, to reconstruct the dynamics of vegetation, and to estimate the effect of climatic changes and livestock grazing on the vegetation in the central part of the Negev Desert.     

Composition of plant communities in natural and technogenically disturbed ecotopes on watersheds of the Yamal Peninsula: Floristic diversity

Specific features in the overgrowing of technogenically disturbed areas with completely destroyed soil and plant cover (a sand pit, a causeway, and an off-road vehicle trail) have been studied in the environs of the Bovanenkovo Oil-Gas Condensate Field. It is shown that the vegetation of natural ecotopes and ecotopes disturbed approximately 20 years ago is characterized by a relatively high similarity in the composition of vascular plants. The total species composition of plant communities (including mosses and lichens) and their structure show a considerable loss of floristic and phytocenotic diversity.     

The holocene dynamics of vegetation and environmental conditions on the eastern slope of the Northern Urals

Consideration is given to changes in the vegetation and climatic conditions on the eastern slope of the Northern Urals in the second half of the Holocene as reconstructed on the basis of integrated palynological, botanical, paleocarpological, and radiocarbon analysis of material from a peat bog section in the floodplain of the Loz’va River. The results show that the northern taiga zone of the study region in the period between approximately 5000 and 700 years BP was occupied by forests of southern taiga facies, as the climate was significantly warmer than it is today.     

Comparison of different ecological scales with respect to efficiency in assessing ecological conditions in forests of the Southern Ural region

Ecological scales proposed by H. Ellenberg, E. Landolt, and D.N. Tsyganov have been used to evaluate the roles of three ecological factors—elevation above sea level, soil moisture, and soil nitrogen—in determining the composition of forest communities in the Southern Ural region. The results obtained with all these scales are similar, which indicates that any of them can serve the purpose.     

Long-term dynamics of terrestrial carbon stocks in Austria: a comprehensive assessment of the time period from 1830 to 2000

This article presents a comprehensive data set on Austria’s terrestrial carbon stocks from the beginnings of industrialization in the year 1830 to the present. It is based on extensive historical and recent land use and forestry data derived from primary sources (cadastral surveys) for the early nineteenth century, official statistics available for later parts of the nineteenth century as well as the twentieth century, and forest inventory data covering the second half of the twentieth century. Total carbon stocks—i.e. aboveground and belowground standing crop and soil organic carbon—are calculated for the entire period and compared to those of potential vegetation. Results suggest that carbon stocks were roughly constant from 1830 to 1880 and have grown considerably from 1880 to 2000, implying that Austria’s vegetation has acted as a carbon sink since the late nineteenth century. Carbon stocks increased by 20% from approximately 1.0 GtC in 1830 and 1880 to approximately 1.2 GtC in the year 2000, a value still much lower than the amount of carbon terrestrial ecosystems are expected to contain in the absence of land use: According to calculations presented in this article, potential vegetation would contain some 2.0 GtC or 162% of the present terrestrial carbon stock, suggesting that the recent carbon sink results from a recovery of biota from intensive use in the past. These findings are in line with the forest transition hypothesis which claims that forest areas are growing in industrialized countries. Growth in forest area and rising carbon stocks per unit area of forests both contribute to the carbon sink. We discuss the hypothesis that the carbon sink is mainly caused by the shift from area-dependent energy sources (biomass) in agrarian societies to the largely area-independent energy system of industrial societies based above all on fossil fuels.     

Recovery of natural vegetation and ecological functions of pasture ecosystems in arid steppes of the Cisural region

The results are presented that have been obtained in studies on changes in the species composition, geobotanical characteristics, and productivity of natural vegetation in arid steppes of the Cisural region during the past few decades (1977–2012). Consideration is given to the significance of the soil factor in the processes of transformation of zonal vegetation. The increasing role of arid steppes as a natural barrier to desertification is demonstrated.     

Transformation of ecological conditions of soil and humus substance formation in the urban environment

Ecological conditions of soil formation and specific features of humus substance formation are considered with regard to urban soils of different types formed in the following functional zones: the park zone, residential area, and sanitary protective zone of the Middle Ural Copper-Smelting Plant. The specificity of soil formation in Revda, a typical industrial city of the Middle Urals, is determined by the combined effect of urban and technogenic factors (urbogenesis and technogenesis), with the former being of primary importance. At a constant period of biological activity, the depth of humification is primarily a function of granulometric and chemical composition of urban soils.Translated from Ekologiya, No. 1, 2005, pp. 11–19.Original Russian Text Copyright © 2005 by Meshcheryakov, Prokopovich, Korkina.     

Sand dunes management: a comparative analysis of ecological versus economic valuations applied to the Coastal region in Israel

Mobile coastal dunes are of significant ecological importance both globally and locally. Yet a large portion of these dunes are disappearing due to encroachment of local shrubs and exotic plants, resulting in changes of floristic and faunal composition, and an overall decrease in biodiversity of coastal systems. Active management is therefore required to maintain mobile dune presence. This study focuses on economic valuation of coastal dunes in Israel, based on public and professional ecological perspectives. This comparison allows reflection on the suitability of a contingent valuation method (CVM) to assess ecological restoration and conservation projects. The CVM was applied in Nizzanim LTER nature reserve in Israel, and concurrently, data of plant species composition on stabilized and mobile dunes were used to calculate the ecological value index (EVI) of the different dune states. The EVI was then transformed into monetary terms by combining the public valuation and the relative proportion of the various species to the total coverage. The monetary values derived from the general public and the ecological assessment were then compared and used to estimate the expected change in economic value resulting from a state shift from mobile to stabilized dunes. According to the CVM, the total value of the Nizzanim coastal dunes would drop from 344 to 197 million Israeli Shekels (NIS) (1 Shekel = $0.39) if active management does not take place, a reduction of 42 % in value. However, results from the EVI indicate only a 33 % decrease in ecological value (in monetary terms) in the absence of active management. We suggest that in this case, general public perception is strong enough to justify conservation decisions, even though they are not professional ecologists. However, we still recommend the use of both measures for land use decision making.     

Evidence for the existence of a high-altitude white wagtail (Motacilla alba) population in the Yamal peninsula and the boundaries of its distribution

It has been shown that the white wagtail at the northern limit of its range forms a population or a group of populations with a high degree of independence from conditions of illumination (photoperiod) in the Subarctic and southern Arctic. The boundary between the tundra and boreal populations in Yamal lies in the forest-tundra: wagtails of the tundra population nest north of the 68th parallel, and wagtails of the boreal population nest south of the 66th parallel. The zone between these latitudes is inhabited by representatives of both populations, and active hybridization apparently takes place there.     

Assessment of the state of vegetation and prognosis of its anthropogenic dynamics in specially protected nature areas on the basis of Phytoecological mapping

Methodological approaches to the construction of phytoecological maps are described regarding specially protected nature areas and their specific features. Such maps offer new possibilities for the assessment and analysis of current and predicted states of vegetation.     

Assessment of polychlorinated dibenzo-p-dioxins and dibenzofurans in sludges according to the European environmental policy

The amount of sewage sludge generated in Europe is expected to surpass the 10 million tons/year in 2006 as a result of the waste water treatment process according to the Water Policy in European Union. Sewage sludge is what is left behind after water is cleaned in waste treatment plants and is characterized for this high content in nitrogen and phosphorous that could be of great importance in agriculture as fertilizer or soil conditioner. On the other hand, pollutants like metals and organic contaminants are usually removed from water and are accumulated in the sewage sludge, reaching the food chain if their concentrations are not below the safe limits established by the European legislation. The latter issue is of great concern nowadays and in this sense, different works alert against the use of the sewage sludge in agriculture arguing that serious illnesses, even resulting in death as well as adverse environmental impacts are associated to the application of sewage sludge. This work is a continuation of a former comprehensive survey on of priority organic pollutant in sludges for agricultural purposes carried out by our group in Catalonia and this time is focused on the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), one of the most toxic group of organic compounds listed in the Work Document on Sludge which is the reference tool in this field in Europe and is also included in the Stockholm Convention. Eighty eight samples were collected from the end of 2003 to April 2006 and the concentrations detected were lower than the 100 ng/kg I-TEQ limit recommended by the European legislation (EC, 2000). Thus, sewage sludges generated in Catalonia do not represent a threat to human health if they are used as fertilizers in agriculture.     

Resilience and collapse of artisanal fisheries: a system dynamics analysis of a shellfish fishery in the Gulf of California, Mexico

Analyzing different pathways by which social–ecological systems can loose resilience and enter trajectories of collapse constitutes an important aspect of our quest towards understanding resource sustainability. This paper’s goal was to better understand the effect of a particular class of disturbance—the accumulative effects of routine stressors—in the context of marine social–ecological systems. To that effect, we built a system dynamics model using empirically collected institutional and biological field data of an artisanal fishery in the Gulf of California, Mexico. Among our findings, we identified different scenarios under which even very small endogenous changes in the relationship between ecological and institutional variables can send a seemingly resilient system into a trajectory of collapse. We discuss why these types of disturbances are so difficult to prevent and be identified by the users of the resource, as well as potential strategies to address these challenges.     

General analysis of forest vegetation in the south of the Far East with regard to the feeding of wild ruminants (Artiodactyla, Ruminantia)

Vegetation in the main types of forest landscapes in the south of the Far East has been analyzed with regard to the dependence of population density and spatial distribution of five wild ruminant species on the main parameters of phytomass. The results have shown that the majority of ruminant species at their current population density never suffer from insufficient food supply. A high population density of the sika deer (Cervus nippon) is the only factor that may cause degradation of vegetation in the study region. The present-day population density of ruminants in their habitats does not depend on the amount of phytomass and species diversity of forage plants. Conversely, there is a strong relationship between the highest population density of ruminants recorded during the past 50 years and the phytomass stock of forage plants in their habitats.