부산대학교 도서관

Pollen shedding can produce rapid, abundant exchanges of nutrient-rich biomass from plant canopies to the surface. When pollen deposits onto understory plants, it can be washed off during storms via throughfall (a drip flux) and stemflow (a flux down plant stems). Pollen deposition may also alter the organismal community on plant surfaces, changing other biological particulates transported by throughfall and stemflow. We report concentrations and fluxes of pollen and other biological particulates (flagellate cells, nematodes, rotifers, mites and hexapodans) in throughfall and stemflow from an understory forb, Eupatorium capillifolium (Lam. dogfennel), during a Pinus palustris (Mill. longleaf pine) pollen shedding event, then compare these results to observations collected when pollen was absent. Pollen flux was 95.6 × 106 grains ha−1 season−1 from dogfennel canopies (63% and 37% transported by throughfall and stemflow, respectively), representing 0.1–3.2 g ha−1. Median concentrations in flagellates, nematodes and rotifers for throughfall and stemflow were higher during pollen shedding; however, mites and hexapodan concentrations were similar regardless of pollen presence. This is the first report of flagellate and hexapodan concentrations in canopy drainage waters. Flagellate concentrations were higher than for other organisms—being similar to those reported for streams, 105–107 cells L−1—and hexapodan fluxes were ~ 50 individuals m−2 per 1 cm of rainfall. These results indicate that throughfall and stemflow can (i) transport ecologically relevant amounts of pollen and organisms from the phyllosphere to the surface, and (ii) that the composition and flux of biological particulates can change markedly during pollen shedding.