CLIMATE CHANGE IN A SOUTHERN HEMISPHERE WINTER-RAIN REGION INFERRED FROM POLLEN ANALYSIS OF FOSSIL HYRAX DUNG ACCUMULATIONS IN THE PAKHUIS PASS, S.W. CAPE, SOUTH AFRICA

Palynology in the Cape winter rain region, in comparison with that in the northern summer-rain region, can be applied to questions concerning the interaction between winter- and summer-rain regions. Pollen in stratified hyrax dung gives a millennial scale record of rocky-slope vegetation (fynbos) of the Pakhuis Pass area, South Western Cape over 20000 years. Regular changes in temperature and moisture conditions are reflected in fluctuations of pollen counts of Restionaceae, Asteraceae types, Cyperaceae, succulents and shrubs. Besides these changes the long term record shows that LGM vegetation was composed of mainly low shrubs (low-spine pollen of Stoebe/Elytropappus type) and “fynbos” (including Ericaceae, Passerina, Cliffortia and Proteaceae), while Holocene vegetation contained more scrub vegetation (including Dodonea and Olea) with succulents and Asteraceae. Results support conclusions based on isotopes in hyrax diet (dung) (Scott and Vogel, 1999) that plants remained typical of a winter-rain environment during the whole study period. Although the boundary between the study area and the summer rain region to the north apparently did not move significantly a limited grass improvement shortly before 2 kyr may be related to a slight increase in summer-rain following the pattern of optimal conditions north of the study area. Over the long term, however, inferred moisture patterns are at times the opposite of that in proxy records to the north, e.g., showing moist conditions in the early Holocene and drier conditions in the Middle Holocene.