Deposition of airborne pine pollen in a temperate pine forest

Deposition of airborne pine pollen was examined in a temperate pine forest, Korea. Durham gravity pollen collectors were employed to measure amounts of pine pollen deposition in the field and macronutrients input by pine pollen was analyzed in the laboratory. In 1999, pine pollen deposition began just before May 4^th and lasted for about three weeks. In 2000, pollen anthesis started May 5^th and lasted over three weeks. Two species of pine differed in the timing of pollen release, with Pinus rigida beginning pollen release a few days earlier than that of P. densiflora. Pine pollen release dates varied between years, occurring earlier in years with warmer spring temperatures. Annual pine pollen deposition was slightly different over the two sampling years; 11.2 kg/ha (ca. 4975 grains/cm²) in 1999 and 9.2 kg/ha (ca. 4097 grains/cm²) in 2000. The values of nutrient deposition from airborne pine pollen were 232 g/ha N, 30 g/ha P, 109 g/ha K, 23 g/ha S, 10 g/ha Mg in 1999 and 196 g/ha N, 19 g/ha P, 70 g/ha K, 13 g/ha S, 6 g/ha Mg in 2000. Our values were about 1/300 that of pine litterfall. The contribution rate of pine pollen in annual nutrient input was about N 1/76, P 1/16 and K 1/23 that of litterfall. These values suggest that nutrient input from airborne pine pollen is small compared to that from known litterfall, highly episodic pine pollen deposition suggests that pine pollen may play a disproportionately role in the temperate pine forest nutrient input.