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- Buckland, Philip, 1973-
(författare)
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The development and implementation of software for palaeoenvironmental and palaeoclimatological research : the Bugs Coleopteran Ecology Package (BugsCEP)
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis documents the development and application of a unique database orientated software package, BugsCEP, for environmental and climatic reconstruction from fossil beetle (Coleoptera) assemblages. The software tools are described, and the incorporated statistical methods discussed and evaluated with respect to both published modern and fossil data, as well as the author’s own investigations. BugsCEP consists of a reference database of ecology and distribution data for over 5 800 taxa, and includes temperature tolerance data for 436 species. It also contains abundance and summary data for almost 700 sites - the majority of the known Quaternary fossil coleopteran record of Europe. Sample based dating evidence is stored for a large number of these sites, and the data are supported by a bibliography of over 3 300 sources. Through the use of built in statistical methods, employing a specially developed habitat classification system (Bugs EcoCodes), semi-quantitative environmental reconstructions can be undertaken, and output graphically, to aid in the interpretation of sites. A number of built in searching and reporting functions also increase the efficiency with which analyses can be undertaken, including the facility to list the fossil record of species found by searching the ecology and distribution data. The existing Mutual Climatic Range (MCR) climate reconstruction method is implemented and improved upon in BugsCEP, as BugsMCR, which includes predictive modelling and the output of graphs and climate space maps. The evaluation of the software demonstrates good performance when compared to existing interpretations. The standardization method employed in habitat reconstructions, designed to enable the inter-comparison of samples and sites without the interference of differing numbers of species and individuals, also appears to be robust and effective. Quantitative climate reconstructions can be easily undertaken from within the software, as well as an amount of predictive modelling. The use of jackknifing variants as an aid to the interpretation of climate reconstructions is discussed, and suggested as a potential indicator of reliability. The combination of the BugStats statistical system with an enhanced MCR facility could be extremely useful in increasing our understanding of not only past environmental and climate change, but also the biogeography and ecology of insect populations in general. BugsCEP is the only available software package integrating modern and fossil coleopteran data, and the included reconstruction and analysis tools provide a powerful resource for research and teaching in palaeo-environmental science. The use of modern reference data also makes the package potentially useful in the study of present day insect faunas, and the effects of climate and environmental change on their distributions. The reconstruction methods could thus be inverted, and used as predictive tools in the study of biodiversity and the implications of sustainable development policies on present day habitats. BugsCEP can be downloaded from http://www.bugscep.com
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- Gustavsson, Gunnar, et al.
(författare)
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Abrupt forest ecosystem change in SW Sweden during the late Holocene
- 2009
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Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 19:5, s. 691-702
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Tidskriftsartikel (refereegranskat)abstract
- A peat profile from a small raised bog, situated in Sweden was studied for insect, pollen and charcoal analyses in order to reconstruct the late-Holocene forest history of the area. The palaeoecological records cover the last 3700 cal. years. The results were compared with archaeological data, historical documents and palaeoclimate reconstructions from the region. From 1650 cal. yr BC to AD 1310 cal. yr, the study area was characterized by deciduous woodland with a diverse invertebrate fauna. The recorded insects indicate a relatively open or mosaic forest environment with abundance of dead wood. This forest environment was probably maintained by disturbances such as cattle grazing, fire, wood coppicing and small-scale cultivation. At around AD 1310, a major and rapid change in the forest ecosystem occurred, ie, species-rich deciduous woodland was replaced by a species-poor beech forest. The data indicate that a change in land use was the likely reason for the shift in forest type. Grazing and fire ceased, while tree cutting increased. The shift in land use correlates well with political-societal changes in the region during Mediaeval time. Climate changes seem to have influenced the wetland environment, but there is no obvious correlation between major or minor shifts in forest ecosystem and reconstructed climate changes. Today, nature conservationists regard the beech forests of Halland as remains of primeval forests hosting a unique flora and fauna. Our results give new insights and challenge that view.
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- Lemdahl, Geoffrey, et al.
(författare)
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BEETLE RECORDS : Late Pleistocene of Europe
- 2007
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Ingår i: Encyclopedia of Quaternary Science. - : Elsevier. - 9780444527479 ; , s. 190-196
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The Upper Pleistocene period spans the time from the last (Eemian, Ipswichian) interglacial period, 120 ka, to the termination of the last (Weichselian, Devensian) glaciation 11.5 ka. It was characterized by a complex sequence of climatic oscillations that ranged from glacial episodes, when ice sheets covered much of the Northern Hemisphere, to interglacial and interstadial intervals when the climate was often as warm as, or warmer than, that of the present day. Each of these events disrupted the biological systems so that many species had to alter their geographical ranges in order to track acceptable climates from one place to another across the continent. These movements of species enable estimates to be made of the terrestrial climatic history of the period. Among the most valuable of climatic indicators are the Coleoptera (beetles) whose robust exoskeletons are readily preserved in waterlogged sediments. Using the well-known mutual climatic range method on species from fossil beetle assemblages, it has been possible to make quantified estimates of the thermal climatic conditions during various phases of the Quaternary in western Europe. These show that, during warmer intervals, mean July temperatures were at least 3° C warmer than now, and winter figures were not much different from those of the present day. During the colder episodes, the mean July temperatures were at least 7° C colder than the present and winter temperatures were very much colder and of Siberian intensity. Rates of change from one climatic regime to another were often very rapid and may have involved a rise in summer temperature of 1° C per decade.
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- Lemdahl, Geoffrey, et al.
(författare)
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Senglaciala granskogar i Sydsverige?
- 2005
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Ingår i: Svensk Botanisk Tidskrift. - 0039-646X. ; 99:3-4, s. 183-186
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Tidskriftsartikel (refereegranskat)
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- Olsson, Fredrik, 1975-, et al.
(författare)
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A continuous Holocene beetle record from the site Stavsåkra, southern Sweden: implications for the last 10 600 years of forest and land use history
- 2009
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Ingår i: Journal of Quaternary Science. - : John Wiley & Sons, Ltd. - 0267-8179 .- 1099-1417. ; 24:6, s. 612-626
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Tidskriftsartikel (refereegranskat)abstract
- Beetle remains from a small bog in southern Sweden contribute information concerning the forest history of the study area. The study shows that beetles are valuable indicators of woodland structures such as openness, field vegetation, presence of dead wood and disturbance factors such as climate change, fire regimes, grazing and land use. The early Holocene, ca. 8600-6450 cal. BC, was characterised by open, pine-dominated woodlands maintained by fire and grazing disturbances. The changes in the wetland fauna, between 8600 and 7500 cal. BC, correlate well with low lake levels in southern Sweden. During the mid Holocene, ca. 6450-2400 cal. BC, the woodlands were relatively dense, with few openings in the canopy. Around 4200 cal. BC, there was a shift to a dominance of deciduous trees. Fire and grazing pressures were particularly low. Numbers of aquatic and hygrophilic beetles indicate dry conditions between ca. 5000 and 3000 cal. BC. During the late Holocene, ca. 2400 cal. BC to present, the woodlands opened up mainly through increased land use. The main disturbance factors were fire and grazing. The beetles indicate the formation of heather-dominated heathland around 800 cal. BC.
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