AEROPALYNOLOGICAL INVESTIGATION IN TAICHUNG, TAIWAN, 1993-1995

The airborne pollen spectrum was investigated in Taichung, Taiwan, in two consecutive years using a 7-day volumetric recording trap. In tota l, 323,745 pollen grains of seed plants and fern spores were counted, with a mean of pollen concentration of 30.8 grains/m(3). In the course of a year, airborne pollen was most abundant in spring and least in s ummer. In dry days from late March to mid April, the pollen concentrat ion usually remained around 1,000 to 2,000 grains/m(3) for two or thre e hours in the morning. During these two years, the highest hourly pol len value was recorded during 11-12 A.M., on 15 April 1994 with a mean of 5,306.7 grains/m(3). The pollen spectrum obtained did not reflect the floristic composition of Taichung city. The important pollen taxa were Broussonetia (66.83%), Casuarina equisetifolia (5.66%), Trema ori entalis (5.02%), Poaceae (4.15%), Humulus scandens (2.77%), Alnus (1.9 9%), Morus (1.38%), Mallotus (1.14%) and Macaranga (1.04%). Most of th em are common wild Amentiferae plants in lowland Taiwan. Broussonetia is extremely important for future studies of pollen allergy in Taiwan, not only for the allergenicity of its pollen, but also for the superi ority of its pollen productivity and pollen dispersibility.