Macronutrient input from pollen in two regenerating pine stands in southeast Korea

Abstract

This study examined macronutrient input from pollen in two naturally regenerating pine stands in southeast Korea. Durham gravity pollen collectors were used to measure pine pollen deposition and the macronutrients in the collected pine pollen were analyzed. In 1998, pine pollen deposition began just before 18 April and lasted for approximately 2 weeks. Total pine pollen deposition differed between the two sampling sites; 27.5 kg ha−1 was collected from the mature stand and 17.7 kg ha−1 was collected from the young stand. The values for nutrient deposition from pine pollen are 549 g ha−1 N, 78 g ha−1 P, 240 g ha−1 K, 45 g ha−1 S and 22 g ha−1 Mg at the mature stand and 353 g ha−1 N, 51 g ha−1 P, 151 g ha−1 K, 27 g ha−1 S and 14 g ha−1 Mg at the young stand, suggesting that nutrients from pine pollen contribute to forest nutrient cycling. The pine pollen deposition values obtained from our study (17.7–27.5 kg−1 ha−1 year−1) are approximately 1/115–180‐fold that of pine litterfall in Korea. If we take pollen nutrients into account, the contribution rate of pollen to the annual nutrient input is very high in our study (N 1/30, P 1/5, K 1/9 that of litterfall). Macronutrient deposition from pine pollen is concentrated temporally in spring. Although the annual contribution of nutrient mass by pollen is small compared to that of litterfall, the rapid turnover rate of pollen nutrients combined with episodic deposition suggests that pollen may play a disproportionate role in temperate pine forest nutrient cycling.