Pollen transport and representation in the Coast Mountains of British Columbia. I. Flowering phenology and aerial deposition

Abstract

Two years of aerial pollen trapping at two lakes surrounded by coniferous forest are summarized. Most of the annual pollen and spore deposition occurs between February and May (86%), followed by 10% during the summer, and 4% during the fall – winter nonflowering period. Annual aerial influx is very similar at both Marion and Surprise lakes, ca. 5000 grains∙cm⁻²∙year⁻¹. The annual frequency spectra are also equivalent, with a predominance of Cupressaceae (32%) and Alnus (35%), followed by Tsuga heterophylla (8 – 11%), grasses (8 – 10%), and pine (2 – 3%). Regional, rather than local or extralocal pollen, is estimated to account for about 90% of the annual aerial deposition at both lakes. The data also suggest that pollen transport is predominantly upslope in this mountainous area.