Resource Management and Geography - Research Publications
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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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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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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.