ISSN:0035-919X    

DOI:10.1080/00359199509520326

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This review examines pollen rain-vegetation studies that have been conducted in South Africa and Namibia. Many fossil pollen studies conducted now include a contemporary pollen analysis using either surface soil samples and/or passive pollen samplers. Statistical analyses, including multiple discriminant analysis, have been undertaken to determine any possible contemporary pollen-vegetation relationships and to enable modern analogue vegetation communities to be identified in the fossil pollen spectra and hence strengthen the conclusions of the fossil analysis. Such studies in South Africa have extended the limited understanding of the contemporary pollen rain-vegetation relationship and enables the interpretation of fossil pollen spectra to be carried out with greater confidence. This in turn lends greater credibility to Quaternary environmental change models required to help understand present and possible future environmental change.

ISSN:0035-919X    

DOI:10.1080/00359199509520327

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Micromammalian remains are relatively readily preserved in closed archaeological and palaeontological sites, as well as in modern barn-owl pellets, which act as controls. The animals themselves tend to have fairly precise habitat requirements and to respond quickly to environmental change. Long sequences of samples from the past can provide unique information on the nature and extent of climate change, as well as on conditions before human activities became a major agent of environmental change. So far, the evidence indicates that warm periods during the last 125 000 years in South Africa have not all been characterized by the same conditions. The evidence further indicates that during the last millennium the effects of natural climatic variability have only outweighed the depredations of humans in the presently more arid parts of South Africa. Several general conclusions arising from these facts could have a bearing on future planning. 1) Each investigation must be undertaken at the correct temporal and geographic scale; 2) Unsupported extrapolation from one event or region to another is unlikely to be reliable; 3) More southern grid points are needed in GCMs before accurate predictions can be made.

ISSN:0035-919X    

DOI:10.1080/00359199509520328

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper presents additional evidence for former cryogenic conditions at high altitudes in southern Africa. The evidence consists of two types of erosional hollows and two classes of sediments. The altitude of each location is plotted separately against latitude. This enables minimum elevations for the Pleistocene land-forms to be derived. Minimum altitudes for these relict cryogenic landforms show an inverse altitudinal gradient against latitude that steepens southwards. No distinction in gradient between the east and the west of the subcontinent is identified.

ISSN:0035-919X    

DOI:10.1080/00359199509520329

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359199509520330

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A description is given of Thomas Maclear's measurement of an arc of meridian, the triangulations for which formed the foundation of geodesy in South Africa.

ISSN:0035-919X    

DOI:10.1080/00359199509520331

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The publications of Thomas Maclear—astronomer, scientist, poet—are discussed, and his contributions to nineteenth century astronomy and geodesy in South Africa outlined. Appended to the article is a bibliography of his published works, followed by a list of references on Thomas Maclear, the man and his work.

ISSN:0035-919X    

DOI:10.1080/00359199509520332

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

For many years, prior to the advent of the electronic age, the South African survey system with its well monumented control beacons was the envy of many countries, especially those of the New World.

ISSN:0035-919X    

DOI:10.1080/00359199509520333

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In commemoration of the bicentenary of the birth of Sir Thomas Maclear a description and assessment is given of his life and contributions to astronomy. Maclear was director of the Royal Observatory, Cape of Good Hope, from 1834 to 1870.

ISSN:0035-919X    

DOI:10.1080/00359199509520334

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359199509520335

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor