- 一般社団法人 日本アレルギー学会
- アレルギー (ISSN:00214884)
- vol.18, no.1, pp.56-69,90, 1969
1. Tree pollen season extended from the first week of April to the last week of June and significant trees were Birch, Alder, Oak, Spruce, Fir, Yew and Maple. Grass pollen season extended from the first week of June to the last week of August, but grass pollens were found until the middle of September. The most significant and abundant grasses were Orchard grass, Timothy, June grass, Rye grass and Red top, all of which were introduced. Weed pollens were found from the first week of June to the middle of September. Dominant weeds were Sheep sorrel, Blunt-leaved dock and Wormwood (Artemisia montana), but Short regweed, allergically troublesome plant, was not found anywhere in this area. The wormwood was found abundantly, showing a peak in the pollen counts at the begining of September in Sapporo area. 2. Variation in pollen incidence from year to year was wider in trees, particularly Birch, Alder and Maple, than in grasses. Counts of all pollen grains in 1 966 were recorded twice in 1965. Low pollen counts were obtained in the days when it was higher than 80% in relative humidity, and rainfall. Variation in pollen incidence from place to place was wide and high counts occured locally in the neighbouring area of Sapporo. Cyclic pollen releases in grasses were confirmed to particular times of day and the majority of the pollen was released in the early morning with mild wind. 3. The comparative study with the new pollen sampler (Durhams' standard sampler) and the old type of instrument (the pollen slide shelter employed in 1965 and 1966) during the grass season of 1967 revealed that higher counts were obtained with the old type than the new. 4. Vegetation of Hokkaido and Sapporo were described briefly from the point of view of allegy. Finally, the implication of this study were discussed.