Resource Management and Geography - Research Publications
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ItemEnvironmental context of the Kura-Araxes culture(Editions CNRS, 2014)
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ItemThe ecological impact of oceanic island colonization - a palaeoecological perspective from the Azores(WILEY, 2012-06)Aim In many cases, human colonization drastically modified the ecosystems of remote oceanic islands before scientists arrived to document the changes. Palaeoecological records before and after human colonization provide insights into the original ecosystems and an assessment of subsequent human impact. We used pollen analysis to compare the impact of 15th century colonization of the Azores with that of natural disturbances such as volcanic eruptions and climate changes. Location Azores archipelago, Atlantic Ocean. Methods Sediment records from three highland sites in the Azores (on the islands of Pico and Flores) were dated radiometrically and analysed palynologically. Pollen taxa were classified as native, endemic or introduced based on comparison with flora lists. Data were statistically zoned and temporal trends identified using detrended correspondence analysis. Results Human colonization of the Azores resulted in rapid, widespread, persistent vegetation changes on a scale unprecedented in the last 2700 years, detectable through the decline of dominant trees, the spread of grasses and fire‐tolerant species, the introduction of exotic plants, evidence for grazing and fire, and changes to soils and moisture availability. During the same period, volcanic eruptions appear to have had more localized impacts on the vegetation, lasting 500–1000 years and favouring endemic taxa. The effect of late Holocene climatic changes on the highland vegetation of the Azores seems to have been minor. Palaeoecological data indicate that at least two plant species went extinct on Pico after human colonization and that some plants regarded as introduced were almost certainly part of the original flora of the islands. Despite a consistent signal of human impact, compositional differences between Juniperus brevifolia communities on Pico and Flores remained after colonization. Main conclusions Human colonization had a greater impact on the pristine vegetation of Pico and Flores than climatic changes and volcanic activity during recent millennia. The similarity between post‐colonization changes on the Azores and other oceanic islands suggests a consistent pattern and scale to historical‐era human impact on otherwise pristine ecosystems. These characteristics could be used to further elaborate biogeographical theory and direct conservation efforts towards species that appear most susceptible to human activity.
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ItemA long-term perspective on biomass burning in the Serra da Estrela, Portugal(PERGAMON-ELSEVIER SCIENCE LTD, 2012-11-08)
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ItemEnvironmental conditions in the SE Balkans since the Last Glacial Maximum and their influence on the spread of agriculture into Europe(PERGAMON-ELSEVIER SCIENCE LTD, 2013-05-15)
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ItemEstimating absolute pollen productivity for some European Tertiary-relict taxa(SPRINGER, 2010-08)
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ItemA 5600-yr history of changing vegetation, sea levels and human impacts from the Black Sea coast of Georgia(SAGE PUBLICATIONS LTD, 2007)Mid-late Holocene pollen evidence from the Ispani-II Sphagnum bog in lowland Western Georgia shows that 4500 years ago Castanea (chestnut)-dominated woods rapidly declined to be replaced by alder swamps and, later, during the first millennium be, by open, marshy landscapes in which fire played a prominent part. Around 1900 years ago, Sphagnum blanket bog encroached on the marshes and dense Fagus-Carpinus (beech-hornbeam) forest enveloped the surrounding land. This vegetation remained until the mid-twentieth century, when forests were clear-felled and marshes were drained for large-scale, mechanized agriculture. Previous studies have emphasized climate's governing role in setting the course of Holocene vegetation development in lowland Western Georgia, but our results provide little support for this hypothesis. To a much greater degree, episodes of coastal subsidence, sea-level rise and human impact have shaped the vegetation history of coastal Western Caucasus.
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ItemCalluna vulgaris and Spiranthes amoena in the Colchis mire flora: weeds or relicts?(Sciendo (De Gruyter), 2007)ecent botanical discoveries in the Colchis lowland of Western Georgia have renewed interest in the extensive Sphagnum peat bogs along the Black Sea coast. This area has long been recognized as an important refugium for thermophilous, Tertiary relict plants, but is also home to some plants typical of the boreal zone. In this paper, we present palynological and historical data that calls into question the idea that Calluna vulgaris (L.) Hull and Spiranthes amoena (Bieb.) Spreng., the Euro-Siberian elements recently discovered in the Colchis Sphagnum bogs, are adventive. We argue instead that they are relicts of late Pleistocene age that elsewhere in the Western Asia were pushed out by afforestation and sea-level rise during the early-mid Holocene.
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ItemA survey of modern pollen and vegetation along an altitudinal transect in southern Georgia, Caucasus region(ELSEVIER SCIENCE BV, 2004)This paper describes the pollen representation of vegetation patterns along an altitudinal transect in the South Caucasus region. Surface sediments from eight small- to medium-sized lakes and wetlands were analysed for modern pollen, and the results analysed numerically using detrended correspondence analysis (DCA) and dichotomised ordination (TWINSPAN). Pollen spectra from the semidesert region have a clear palynological signal characterised by an abundance of Chenopodiaceae. Differentiation of oak forest, upper tree-line and subalpine communities is more difficult: all are dominated by arboreal pollen (AP) types. The authors propose a number of indicator pollen types and pollen threshold values that may assist in detecting tree-line variations and deforestation events in Holocene pollen diagrams.
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ItemClimatic and human influences on vegetation dynamics around Tbilisi over the past 6000 years(Georgian Academy of Sciences, 2005)
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ItemSediments as archives of industrialisation: evidence of atmospheric pollution in coastal wetlands of southern Sydney, Australia(Springer, 2003)The history of heavy metal pollution in southern Sydney was reconstructed from wetland sediments using chemical analysis. Seven wetlands along the Pacific coast were examined for present day concentrations of acid-extractable Cd, Cu, Fe, Pb and Zn. Additionally, four of these sites were cored in order to assess past levels of these metal contaminants, changes in organic content and magnetic susceptibility variations. The low nutrient status and closed catchments of the study sites suggested that the pollutants were predominantly derived from atmospheric sources. Surficial sediments were enriched with Cd, Cu, Fe, Pb and Zn levels 5.0, 16.4, 22.7, 8.2 and 22.5 times baseline levels, respectively. In some cases, the concentrations of trace metals were in excess of environmentally acceptable levels. The results show a strong spatial association between sources and levels of pollutants, and the increase in metals levels in sedimentary records corresponds well to documentary historical evidence.This study demonstrates the utility of coastal wetlands in the reconstruction of atmospheric pollution histories, and their particular vulnerability to contamination from airborne pollutants in urban areas.