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SJOERD BOHNCKE LEX WIJMSTRA JAN VAN DER WOUDE HENNY SOHL 《Boreas: An International Journal of Quaternary Research》1988,17(3):385-402
Pollen analyses of three Late Weichselian Late-Glacial lake sediment successions provided a basis for the construction of pollen assemblage zones for The Netherlands. Special attention is paid to the behaviours of Populus in the Alleröd boreal forest. Some aspects of the autecology of Juniperus and Hippohaë and the dynamics of birch and pine forests are discussed in the light of the observed succession. The Late-Glacial vegetational succession in The Netherlands is compared with data published for neighbouring NW European countries. It is concluded that differences in precipitation (snow cover) along a west-east transect to a great extent determined the inferred differences in vegetational development. 相似文献
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SJOERD BOHNCKE LEX WIJMSTRA 《Boreas: An International Journal of Quaternary Research》1988,17(3):403-425
The Late-Glacial infills of three lake successions in The Netherlands have been analysed for their palaeobotanical content (pollen, macroremains) as well as for their physical and chemical characteristics. The macro-botanical analysis in association with the pollen analysis permitted the reconstruction of relative lake level fluctuations for each lake. There appeared to be good agreement between the three lake successions. Supporting evidence for the presence of alternating dry and wet phases was found in the geochemical results. The termination of the Bölling biozone coincides with a lowering of the lake levels that persisted throughout the Older Dryas. Water levels restore at the beginning of the Allerod biozone. Several fluctuations are recognized during the Allerod. The end of the Alleröd is characterized by a second major lowering in the lake levels, leading to an interruption in the sedimentation in cores from the fringe zone. Water depth increases at the beginning of the Younger Dryas biozone. A third major minimum in the lake levels is reached towards the end of the Younger Dryas biozone, probably explaining the recurrent hiatus at the transition to the Holocene record. Pollen concentration data in association with chronostratigraphical data provided the construction of sedimentation rate curves. Minima in these sedimentation rate curves appeared to correlate with periods of low lake level. The loss on ignition curve in association with the sedimentation rate data allowed an approximation of the organic production of the lakes involved. It revealed that the darker appearance of the Allerödin the lithologycan be ascribed mainly to a retardationin the sedimentation rate and not to a major increase in the organic production of the lakes. 相似文献
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This paper reports on some individual constructions of ageing and how these relate to the mutual sustainability of lives and communities in the changing rurality of New Zealand in the 1990s. The Arena Society model is used to organise a discussion of the impact of technology on settlement systems, with reference to changes in the provision of banking services and their impact on the elderly. The views of older people living in the village of Tirau in the Waikato are used to ground the analysis in human experience. The concluding discussion focuses on the potential contribution of older rural residents to the ‘multiple agency’ that communities will need for survival in the ‘open society’. 相似文献
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This paper examines the potential of digital mapping techniques for the analysis and mapping of shoreline change. The discussion is illustrated through a case-study of the coastal environment of TePuru in the Coromandel Peninsula. 相似文献
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This paper examines the impact of periurban development on the physical capacity of the roading network in an area to the north west of Tauranga, exploring the potential impact of subdivision, population growth and building of new residences in rural areas with respect to pressures on rural roads. Geographic Information Systems (GIS) are used to integrate large volumes of complex road and other data, model traffic flow generated from these data, display the outcomes effectively and test the effect of different development scenarios in a particular peri-urban environment. 相似文献
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