Contributions to the aerobiology of Shillong. I. Studies on the seasonal variations of atmospheric pollen and fungal spores

Abstract

Total air-spora, pollen grains, fungal spores and other biological materials constituted 22, 72 and 6% respectively. The low incidence of pollen in atmosphere was mainly due to high altitude of the place and may also be due to less number of anemophilous plants in the locality. Pollen flora showed three peak periods: March, May and September, and each period was dominated by a specific pollen type. There was a distinct correlation between wind velocity and concentration of pollen in the atmosphere. Low frequency of pollen during June-August is probably due to heavy rainfall, which washed down the pollen. The frequency of the fungal spores was maximum during September (very high humidity) and minimum in March (low humidity) with two peak periods in June and September. Further, the cause of seasonal fluctuations of air-borne dominant fungal spores is discussed.