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Fossil pollen, stomata and charcoal were examined from a lakesedimentary sequence in the Glen Affric National Nature Reserve,one of the largest areas of remnant native pine woodland inScotland, in order to assess ecosystem dynamics over the last11 000 years. Results reveal that pinewood communities havebeen continuously present in East Glen Affric for the last 8300years. Pinus sylvestris first arrived in the area around 9900cal. BP, but occurred in only low abundance for the subsequent1600 years. Pine populations expanded around 8300 cal. BP andremained in relatively constant abundance throughout the remainderof the Holocene. There is no evidence of a hypothesized regionalmid-Holocene pine decline at the site. Charcoalresults reveal that pinewood communities in East Glen Affricdo not appear to have been dependent on fire for either theirestablishment or their maintenance as has previously been suggested. 相似文献
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G Froyd 《The Veterinary record》1969,85(25):705-708
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Holocene palaeo-invasions: the link between pattern, process and scale in invasion ecology? 总被引:2,自引:1,他引:1
Lindsey Gillson Anneli Ekblom Katherine J. Willis Cynthia Froyd 《Landscape Ecology》2008,23(7):757-769
Invasion ecology has made rapid progress in recent years through synergies with landscape ecology, niche theory, evolutionary
ecology and the ecology of climate change. The palaeo-record of Holocene invasions provides a rich but presently underexploited
resource in exploring the pattern and process of invasions through time. In this paper, examples from the palaeo-literature
are used to illustrate the spread of species through time and space, also revealing how interactions between invader and invaded
communities change over the course of an invasion. The main issues addressed are adaptation and plant migration, ecological
and evolutionary interactions through time, disturbance history and the landscape ecology of invasive spread. We consider
invasions as a continuous variable, which may be influenced by different environmental or ecological variables at different
stages of the invasion process, and we use palaeoecological examples to describe how ecological interactions change over the
course of an invasion. Finally, the use of palaeoecological information to inform the management of invasions for biodiversity
conservation is discussed. 相似文献
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G Froyd 《The Veterinary record》1975,97(25-26):492-495
Over a period of 15 months data were collected from abattoirs in Great Britain on 213,082 cattle and 362,838 sheep livers to determine the distribution and prevalence of damage by Fasciola hepatica. The stock came from 8239 farms, and from livestock markets in 81 counties. 53 per cent of the farms had sent affected stock, with significant percentages in eastern as well as the western counties of England and Scotland. 21 per cent of all cattle and 7 per cent of all sheep livers examined were affected. In both species, the percentage of adult stock affected was more than double that of young stock. The condemnation rate in cattle was relatively constant throughout the year. The effects of infestation are more widely distributed than has been generally recognised. Greater emphasis should be placed on the control of chronic fascioliasis in cattle. 相似文献
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