[Relationships between atmospheric Sugi (Japanese cedar)-pollen counts and indices of climatic conditions]

Atmospheric pollen surveys have been conducted using Durham's standard sampler for 12 years in Toyama Prefecture. The relationships between Sugi (Japanese cedar, Cryptomeria japonica D. Don) pollen and some indices of climatic conditions were analyzed. The results were as follows: 1. Total pollen counts showed a tendency to increase for 12 years, although the variation of the count was relatively large. 2. Significant correlations were found between pollen counts and some indices of the climatic conditions in July of the previous year, such as duration of sunshine, mean daily temperature and daily maximum, as well as minimum temperature. 3. Significant correlation was found between pollen count and duration of sunshine in January and March, and the amount of snowfall in March of the observed year using multiple regression analysis. Pollen counts were shown to be relatively high in years with short sunshine in January and long sunshine and heavy snow in March.