Holocene Dynamics of Vegetation and Ecological Conditions in the Center of the East European Plain

Changes in the vegetation and fire regimes in the central East European Plain during the second half of the Holocene have been reconstructed based on the results of paleobotanical analysis and radiocarbon dating of material from a section of peat deposit in the Mordovia State Nature Reserve. It has been shown that birch–pine forests were widespread in the region between 7000 and 5000 yr BP, with the frequency of fires in that period being high (the fire return interval ranged from 10–20 to 100 years). Beginning from 5000 yr BP and to the early 20th century, broadleaf forests were dominant, with the fire return interval increasing to 300–500 years or longer.     

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.     

Holocene dynamics of forest ecosystems on the upper plateau of the Volga Upland

Main stages in the development of forest ecosystems on the upper plateau of the Volga Upland in the Holocene have been reconstructed by analyzing palynological assemblages from peat deposits. Dominance of the forest landscape in the region began in the Boreal time. Pine and, to a lesser extent, birch were the main forest-forming species, whereas the role of spruce was never significant. Broad-leaved species appeared in forests in the early Atlantic time. The formation of floodplain and upland bogs began at the end of the Boreal time and in the first half of the Atlantic time, respectively. Significant anthropogenic changes in the vegetation began in the Subboreal time.     

Empirical and theoretical evidence concerning the response of the earth's ice and snow cover to a global temperature increase

As a guide to the possible effects of a CO₂-induced warming on the cryosphere, we review the effects of three warm periods in the past, and out theoretical understanding of fluctuations in mountain glaciers, the Greenland and Antarctic ice sheets, ground ice, sea ice and seasonal snow cover. Between 1890 and 1940 A.D. the glaciated area in Switzerland was reduced by over 25%. In the Hypsithermal, at about 6000 BP, ground ice in Eurasia retreated northward by several hundred kilometres. In the interglacial Stage 5e, at about 120 000 BP, global sea-level rose by over 6 m. Fluctuations of mountain glaciers depend on mesoscale “weather” and on their mechanical response to it. Any melting of the Greenland ice sheet is likely to be slow in human terms. The West Antarctic ice sheet (its base below sea-level) is susceptible to an ungrounding, and such an event may have been the cause of the sea-level rise above. The East Antarctic ice sheet is susceptible to mechanical “surges”, which might be triggered by a warming at its margin. Both an ungrounding and a surge might occupy less than 100 yr, and are potetially the most important ice changes in human terms. Modelling studies suggest that a 5°C warming would remove the Arctic pack ice in summer, and this may be the most significant effect for further climatic change.     

Holocene dynamics of vegetation and ecological conditions in the southern Yamal Peninsula according to the results of comprehensive analysis of a relict peat bog deposit

A comprehensive analysis of samples from a frozen peat deposit in the upper reaches of the Khadytayakha River by palynological, carpological, entomological, and radiocarbon methods has been performed to reconstruct changes in the regional and local vegetation and climatic conditions during the Holocene. The results show that this peat deposit was formed from 8000 to 5000 years BP. During that period, the climate in the southern Yamal Peninsula was considerably warmer, and the present-day subarctic shrub tundra zone was occupied by plant communities of spruce, birch, and larch forests.     

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.     

Growth of the nesting colony of slaty-backed gulls (Larus schistisagus) and plant cover degradation on Shelikan Island (Taui inlet, the Sea of Okhotsk)

The size of Larus schistisagus nesting colony on Shelikan Island (8 ha in area) has increased from 2000 to 6000 pairs over 18 years. Today, this is the largest colony in the Sea of Okhotsk. The growth of the bird population has entailed catastrophic deterioration of the plant cover accompanied by a decrease in the species diversity of vascular plants: more than one-third of plant species recorded on the island in 1986 have already disappeared, and the establishment of several new plant species cannot compensate for this loss. If the size of the colony increases further, woody vegetation will fully deteriorate and only a thinned herbaceous layer consisting of 15–20 most resistant species will remain on the island.     

Climate changes and tree stand dynamics at the upper limit of their growth in the North Ural mountains

The composition and structure of tree stands near the timberline have been studied on different slopes and at different elevations in the Tylaisko-Konzhakovsko-Serebryanskii Massif, the North Urals. It has been found that the upper limits of tree stands with different degrees of canopy closure have risen considerably (by about 100 m of elevation) since the mid-19th century, although the formation of these stands started as early as the late 18th century. Woodless areas in the eastern part of the massif started to be colonized by Larix sibirica in the late 18th to early 19th centuries; those in the western part, by Picea obovata in the mid-19th century; and in the southern part, by Betula tortuosa in the late 19th century. Analysis of meteorological data provides evidence for warming and increasing humidity of the climate since the late 19th century. Favorable climatic changes that facilitated the expansion of the forest have taken place both in the summer (prolongation of the growing period) and in winter seasons (increase of air temperature and precipitation). The observed differences in the composition and dynamics of tree stands between the studied areas of the mountain range are most probably explained by different requirements of tree species for the depth of snow cover and the degree of soil freezing.     

Long-term dynamic of forest vegetation after reduction of copper smelter emissions

The state of tree and ground vegetation layers in spruce-fir forests around the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) has been repeatedly evaluated in 25 permanent sampling plots at 5- to 10-year intervals (1989–2013). The results have been used to characterize the dynamics of plant communities in the period of reduction of emissions from the smelter. Although the annual amount of emissions has decreased from 150–225 × 10³ t in the 1980s to less than 5 × 10³ t after 2010, the vegetation in the impact zone (1 and 2 km from the smelter) remains severely suppressed: the trees continue to die off, and the diversity of ground vegetation layer is very low. In zones with low and moderate levels of industrial pollution (30 and 4–7 km from the smelter), natural factors associated with windfall disturbance after the 1995 windstorm with snow have played a more important role in the dynamics of forest communities than the reduction of emissions itself.     

Significant rainfall decreases and variations of the atmospheric circulation in the Mediterranean (1950–2000)

This paper aims at identifying the link between significant rainfall decreases (1950–2000) in the Mediterranean basin and the atmospheric circulation at the 500 hPa level. The months and seasons of the subregions with significant rainfall decrease during this period have been identified previously (Norrant and Douguédroit, Theor Appl Climatol 83(1–4):89–106, 2006): October in the Mediterranean Iberia, March in the Atlantic Iberia, January and winter in Greece, and winter in the Near East. Canonical Correlation Analyses based on the monthly and daily data records from 62 rainfall stations and 138 grid points at the 500 hPa level over a Euro-Atlantic window were first calculated to define the TeleConnection Patterns explaining significant regional rainfall decreases. Then, 500 hPa level weather types (ZWTs) of the rainy days with important or little rainfall associated with each Teleconnection Pattern were identified in each subregion. Rainfall-causing disturbances from the Atlantic reach Iberia directly; some of them are regenerated if they reach the Mediterranean. Other disturbances are generated locally near Greece and the Near East (Meteorological Office in Weather in the Mediterranean I: general meteorology, Her Majesty’s Stationery Office, London, 1962). The relationship between significant rainfall decreases and the corresponding 500 hPa level appears to be a nonlinear phenomenon. In all of the studied subregions, a break during the 1970s separates two subperiods differing significantly from each other. Rainfall decrease is due to the higher frequency of important rainfall ZWTs over low rainfall ZWTs, during the first period, which the opposite is true during the second period. Such an inversion could be partially linked with the prevailing North Atlantic Oscillation-positive phase during the last quarter of the twentieth century.     

Dynamics of vegetation in the tundra-taiga ecotone on the Kola Peninsula depending on climate fluctuations

The dynamics of northern forest boundary and the state of vegetation in the tundra-taiga ecotone in the northwestern Kola Peninsula have been evaluated using Landsat satellite images obtained in 1986 and 2005, the years encompassing the period of recent climate warming. Values of the normalized difference vegetation index (NDVI) in these years have been calculated to construct a differential index image reflecting changes in the vegetation. Its analysis has revealed an increase in the density of open forests and in the thickness of dwarf shrub vegetation, which has expanded to the lichen tundra.     

Plant phenology in Germany over the 20th century

Analysis of observational phenological data has indicated that the length of the vegetation period (VP), here defined as the time between leaf onset and leaf colouring (LC), has increased in the last decades in the northern latitudes mainly due to an advancement of bud burst. Analysing the patterns of spring phenology over the last century (1880–1999) in Southern Germany showed that the strong advancement of spring phases, especially in the decade before 1999, is not a singular event in the course of the 20th century. Similar trends were also observed in earlier decades. Distinct periods of varying trend direction for important spring phases could be distinguished. Marked differences in trend direction between early and late spring phases were detected, which can be explained by different trends in March and April mean temperatures. The advancement of spring phenology in recent decades is part of the multi-decadal fluctuations over the 20th century that vary with the species and the relevant seasonal temperatures. However, for all Natural Regions in Germany, spring phases were advanced by about 5–20 days on average between 1951 and 1999, LC was delayed between 1951 and 1984, but advanced after 1984 for all considered tree species and the length of the VP increased between 1951 and 1999 for all considered tree species by an average of 10 days throughout Germany.     

Pleistocene Refugia for <Emphasis Type="Italic">Calluna vulgaris</Emphasis> (L.) Hull Populations in the European Atlantic Region

The distribution of nine chloroplast DNA haplotypes in four insular North-Atlantic and four European coastal Atlantic populations of Calluna vulgaris in the glacial zone of the range has been analyzed in comparison with that in six marginal southern populations in the nonglacial zone of the Atlantic and Mediterranean regions. As a result, two hypothetical Pleistocene refugia (HPRs) for this C. vulgaris population group have been revealed, one in the Cévennes mountain range and the other in the Southern Alps (Trento). Judging from the 1–F_ST value, it has been found that the group of populations in the glacial Atlantic zone and adjacent European coastal Atlantic region is genetically similar to the HPR in the Cévennes at a highly significant level (p ≥ 0.999) and less similar to the HPR in Trento; however, it differs significantly from other Mediterranean and Atlantic populations. It has been concluded that the most probable hypothetical Pleistocene refugium for the recent C. vulgaris populations of the northeastern Atlantic and European coastal Atlantic regions was in the west of the Mediterranean, in the Cévennes, while the additional refugium was in the Southern Alps. Possible directions of the postglacial dispersal and recolonization of habitats by C. vulgaris populations from the western Mediterranean to the northeast of the Atlantic and to Scandinavia have been revealed.     

Past and future perspectives upon landscape instability in Cumbria, northwest England

Geomorphic and lacustrine evidence is used to identify phases of landscape instability in Cumbria, northwest England, British Isles. The temporal and spatial pattern of erosion is used alongside palaeovegetation data from across the region to elucidate the causes of landscape instability in the late Holocene. The lines of evidence include changes in sediment accumulation rate and provenance within the region’s lakes; the hillslope alluvial fan and gully incision record; the lowland fluvial geomorphic record; and pollen analytical data for the late Holocene vegetation history. The sediment supply driven hillslope and lacustrine records suggest that only the 1,200–800 BP and post 600–500 BP erosion episodes were both catchment-wide and directly affected upland hillslopes, with the earlier phases after 5,200 and 3,000–1,600 BP on a lower scale and more restricted spatially. These episodes coincide with major expansions or changes in anthropogenic activity during Neolithic, Iron Age and Romano-British, Norse and late Medieval times. The projected future trajectories of changes in both climate (UKCIP scenarios) and landuse (CAP reform and ESA status) appear unlikely to increase landscape instability, although a shift to greater incidence of storms and high magnitude flood events clearly could. The past shows that the largest increases in erosion and sediment movement occur in the wake of major intensifications in land pressure that primarily affect previously wooded or protected hillslopes, circumstances that land management strategists should mitigate against.     

Sources and sinks of carbon dioxide in terrestrial ecosystems: Is the land's carbon budget balanced under the influence of man?

This contribution deals with the controversy between certain scientists on the role of terrestrial vegetation and soils in the global carbon cycle. The hypothesis of a significant net release from the vegetation, is rejected by geochemists because of the limited capacity of the ocean to take up this excess carbon dioxide. As for the man-influenced tropics, a comparison of the figures for the potential and the current phytomass, as well as plausible demographic arguments, support the assertion put forward by ecologists that the carbon budget of this zone cannot be balanced. The tropics lose about 1.7-3.9 × 10¹⁵ g/yr of carbon to the atmosphere; however, for several reasons, 0.5-2.8 × 10¹⁵ g/yr may be returned to land ecosystem, mostly in other climatic zones. Thus, a balance is achieved on combining low estimates for the losses with high estimates for the gains. From an ecological perspective, this solution is not a very probable one; nevertheless, it cannot conclusively be eliminated.     

Analysis of Successional Dynamics of a Sown Meadow using Ramenskii–Grime’s System of Ecological Strategies

Long-term dynamics (1960–2015) of the species composition of an agrocenosis (sown meadow) in the Far North (Vorkuta district, Komi Republic) have been analyzed from the standpoint of its position in Ramenskii–Grime’s CSR system of ecological strategies. This position has been determined as the weighted average of the coordinates of individual species recorded in each year of the observation period. It has been found that the interruption of regular fertilizer application and hay harvesting leads to a decrease in ruderality score (from 0.46 to 0.29) and an increase in competitiveness score (from 0.31 to 0.46), with the most significant changes taking place after termination of the agricultural regime (complete cessation of fertilizer application and hay harvesting). As shown by analyzing the trajectory of the meadow in the CSR space, termination of economic activities in the tundra agrocenosis does not provide for an obvious recovery of the vegetation characteristic of natural tundra communities.     

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.     

Media Access and Political Efficacy in the Eco-politics of Climate Change: Canadian National News and Mediated Policy Networks

We use a discourse network analysis approach to answer two questions about national news coverage of climate change policy debate in Canada during the period 2006–2010. First, what is the media visibility of actors relevant to policy development and advocacy on climate change? Second, given the political and economic context of climate policy-making in Canada, does greater or lesser media visibility reflect effectiveness in climate policy advocacy? Multiple interpretive frameworks characterize Canadian political discourse about climate change, with fragmentation between the federal government, opposition political parties, provincial governments, and environmental organizations. Contrary to expectations, environmental organizations had high levels of media visibility while the relative invisibility of fossil fuel corporations was notable in the media coverage of Canadian climate discussions. Our findings challenge optimistic accounts of the relationship between media power and political power, and suggest that media power does not necessarily translate to political efficacy.     

The impacts of local farming system development trajectories on greenhouse gas emissions in the northern mountains of Vietnam

The northern mountain region of Vietnam (NMR) is dominated by swidden/fallow farming systems. The fallow land of these systems is populated by small trees and bushes. Since the 1960s the government of Vietnam has tried to limit or stop swiddening and replace it with permanent upland agricultural fields, paddy, fruit trees and animal husbandry. Discussion in the policy debate and literature focuses on the impacts these changes have on local people’s livelihoods. There have been no attempts to evaluate the impact of these changes on greenhouse gas (GHG) emissions. This paper examines the realities of current farming system changes taking place at the hamlet level and other changes that could take place due to government land use policies and extension programs. The paper answers the following questions: How could farming system changes influence net GHGs? Which farming system changes in the NMR, the trajectories of changes that are currently observed or those that would be followed if farmers adhere strictly to government policies and programs, will have a greater affect on the GHG contributions from agriculture in the region? Could ‘clean development mechanism’ (CDM) projects make a difference in the profitability of the pathways mentioned? Results show: (1) if farming systems in the NMR continue along currently observed change trajectories there will be increases in GHG emissions; (2) if the NMR farming systems change according to government policies and programs there will be a net sequestration of carbon in regrowing vegetation during the initial 20 years; (3) over the longer term, in areas where systems change to fit government policies, increased GHG emissions from other changes in the farming systems (e.g. increased paddy and increased pig raising in sties) will overtake the amounts of carbon sequestered in vegetation; (4) CMD projects only make a difference if (a) maximum biomass potential of regrowing fallow can be reached; (b) a favourable baseline is chosen; (c) timing and length of the accounting period is correct; and (d) farmers do not take compensatory action in response to government policies. Given these conditions it does not appear that currently envisioned clean development mechanisms would be beneficial to farmers in the NMR.