Pollen dispersal across the Southern Alps, South Island, New Zealand (1990)
AuthorsRandall, Paul M.show all
The aim of this research was to improve the understanding of modern pollen deposition in central South Island in order to interpret Quaternary pollen profiles. This was accomplished by examining the results from a chain of pollen traps (exposed for one year), moss polsters collected along a transect from Westland across the Southern Alps to Canterbury (with and without addition of exotic spores to facilitate 'absolute' counting) and three short peat monoliths. The role of topography, vegetation type and weather patterns were also briefly assessed. The results were analysed by means of principal components and cluster analyses to identify the respective contribution of different pollen taxa. The conclusions are: 1. Trap and polster results are broadly comparable. 2. With exceptions, caused by local effects such as fire and contributions by adjacent vegetation and taxa introduced since 1850, the monolith profiles show little change over the period studied. 3. Forest sites in Westland were dominated by pollen of local podocarps (Dacrydium cupressinum, Prumnopitys) and broadleaved angiosperm species (Metrosidieros, Quintinia, Weinmannia). Nothofagus fusca type pollen dominates within the beech forest areas, but drops to about 10% a short distance from the forest edge. Poaceae pollen shows low frequencies in forested sites, but dominates in grass/scrubland areas. 4. Sites above the treeline on the Main Divide shows proportionately high counts of exogenous Podocarpaceae pollen. However, the high counts involve no 'real' increase in regional deposition.