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.

花粉脱落可以从植物冠层到地表快速，丰富地交换营养丰富的生物质。当花粉沉积到林下植物上时，可以在暴风雨期间通过穿透（滴流）和茎流（植物茎向下的流）将其洗掉。花粉沉积还可能改变植物表面的生物群落，改变通过穿透和茎流运输的其他生物颗粒。我们报告在穿透和树干流浓度和花粉的通量和其他生物颗粒（鞭毛虫细胞，线虫，轮虫，螨和hexapodans）从下层FORB，泽兰capillifolium一个期间上（Lam。dogfennel），长叶松（长叶松木）花粉脱落事件，然后将这些结果与没有花粉时收集到的观察结果进行比较。来自狗粪冠层的花粉通量为95.6×10 ⁶公顷ha ^-1季节^-1（分别通过穿流和茎流运输的花粉通量为63％和37％），代表0.1–3.2 g ha ^-1。在花粉脱落期间，鞭毛，线虫和轮虫中穿透和茎干的中位浓度较高。但是，无论花粉是否存在，螨虫和六足动物的浓度都相似。这是冠层排水水中鞭毛和六足动物浓度的第一份报告。鞭毛浓度高于其他生物体–与报道的溪流中的浓度相似，为10 ⁵ –10每1厘米降雨，有^7个细胞L ^-1和六足动物通量约为50个个体m ^-2。这些结果表明，穿透流和茎流可以（i）将生态学上相关的花粉和生物体从叶球运输到地表，以及（ii）在花粉脱落过程中，生物颗粒的组成和通量会发生显着变化。