Pollen fall-out from a tropical vegetation mosaic.
Pollen fall-out into 60 Oldfield traps set in 11 localities and a variety of vegetational contexts on an upland in tropical northeast Australia, range from 0.5k to 20k (mean 3.5k)grcm(-2)a(-1). The ranges attributable to the four major vegetation types in which the traps were situated overlap to such an extent as would make it virtually impossible to allocate an 'unknown' pollen count to a vegetation type on the basis of total pollen influx alone. Nevertheless, the composition of the pollen clearly differs according to the vegetation in which it is trapped and the amounts of other vegetation types within at least 100m. Substantial variations in catches from closely placed traps suggest the influence of very local site, including meteorological, conditions on the results. Pollen is carried between vegetation types, much less far from rainforest than from sclerophyll forest and woodland, regrowth scrub or herbaceous vegetation, but there is no numerically significant ubiquitous 'background' fall-out in the region. The data impose some constraints on the interpretation of fossil pollen spectra but also potentially permit a greater precision in some aspects of such applications.
Research School of Earth Sciences, Australian National University, ACT 0200, Canberra, Australia
D
Walker
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Sun