Abstract
We have been conducting a survey on pollen dispersion from Japanese cedar (Cryptomeria japonica) for the last 5 years at five locations in the Kinki area: Kyoto City, Maizuru City (northern Kyoto Prefecture), Kinomoto Town (northern Shiga Prefecture), Moriguchi City (Osaka Prefecture), and Kobe City. The “Warmth Index” was used to evaluate weather conditions that influence pollen dispersion patterns, since the index reflects general weather conditions and is closely related to the growth of plant. The onset of the first full-scale pollen dispersion for each year was almost identical. Since these onsets, dispersion patterns showed late pollen dispersion at Maizuru and Kinomoto where the Warmth Index was low. That total count of cedar pollen was highest in Kinomoto, and lowest at Moriguchi. These results might be reflected by the density of the cedar forest around the each location. The results suggest that the long-distance pollen dispersion from the warm area in Japan plays a key role in early pollen dispersion of Japanese cedar in the Kinki area, and that late pollen dispersion is influenced by vegetation of Japanese cedar in the local area and weather conditions, including the Warmth Index.
