The high-precision radiocarbon calibration curve for short-lived samples (1–4 yr) of the early historical period (3rd millennium BC) presented previously (Vogel et al. 1986) has been further substantiated and extended to link with a similar curve produced by de Jong for part of the 4th millennium BC (de Jong & Mook 1980). The precise dendrochronological age of the sample set measured by de Jong has finally been fixed (de Jong, Mook & Becker 1989), so that the two sets now cover the period 1930–3900 BC, i.e., the Early Bronze Age and Late Chalcolithic periods of the Middle East. The standard calibration curve for the two sets is presented by Vogel and van der Plicht (1993).

The relation between photosynthetic pathway and habitat of the grass species recorded in the desert regions of Sinai, Negev, and Judea was investigated. The climatic conditions and micro-environments in the study area vary considerably, and the distribution of the various species is found to conform to specific patterns which reveal the adaptive advantages of the different photosynthetic pathways. There is also a distinct correlation between the phytogeographic origin of the grass species and the photosynthetic pathways that they utilize.The survey shows that the majority of the grass species in the region are of the C type and all except one of these species belong to the Holarctic domain. This is in accordance with the fact that the region forms part of the Mediterranean winter rainfall regime and that C species have an adaptive advantage where minimum temperatures are low during the winter growing season.The occurence of C species increases with decreasing rainfall and they dominate in those districts where temperatures are high throughout the year. These C grasses are of both Holarctic and Palaeotropic origin according to the classification adopted here, but they are essentially all elements of the Saharo-Arabian, Irano-Turanian, Sudanian, or Tropical phytogeographic regions and are not typical of the Mediterranean or Euro-Siberian floras. The plants with multi-regional distributions that occur in Mediterranean communities may well be intrusive.Analysis of the three subtypes of the C species suggests that the malate-forming NADP-me grasses grow where water stress is not a dominating factor, while the aspartateforming NAD-me grasses are more successful under xeric conditions. The PEP-ck species are not abundant and form an intermediate group between the NADP-me and NAD-me subtypes.

High quality wood core samples were collected from individual Acacia erioloba trees of unknown age in the Kgalagadi Transfrontier Park. In the majority of samples examined, seasonal changes were reflected in the wood anatomy as bands of marginal parenchyma on the polished surfaces of discs or cores. Estimated radiocarbon age was determined by means of 14 C analysis for all samples. There was a strong correlation between the annual growth ring count and estimated radiocarbon age. A correlation was also found between age and stem circumference. Age structure of several A. erioloba populations in the Kgalagadi Transfrontier Park was subsequently determined. It could be demonstrated that the populations growing in the bed of the Nossob River showed poor recruitment; however, no clear relationship was found between flooding and regeneration of A.erioloba in the riverbed. The population growing in the dune field had a healthy age structure.

This list contains 14C dates pertaining to the Stone Age in southern Africa and covers the region from Zambia in the north to Natal and the northern Cape Province in South Africa. The southern and southwestern Cape Province are not included. Descriptions are based on information supplied by the submitters.

Precision 14C analyses have been performed on samples comprising 1 to 4 annual rings from the south-central European dendrochronologic sequence of sub-fossil oak wood covering the period 1930 to 3100 bc. Apart from a major deviation in the 29th century bc, the 14C fluctuations have amplitudes of ca 10‰ and a possible periodicity of 90 years. A 14C peak at 2190 bc has a rise- and decay-time of <20 years indicating rather abrupt changes in the production rate of 14C. The 14C calibration curve derived from these data can be used for precise dating of the Early Bronze Age in the Near East.