期刊名称：Annals of Agricultural and Environmental Medicine
印刷版ISSN：1232-1966
电子版ISSN：1898-2263
出版年度：2007
卷号：14
期号：02
页码：271-271
出版社：Institute of Agricultural Medicine in Lublin
摘要：Although aerobiological data are frequently used as a fl owering sign in phenological
research, airborne pollen counts are infl uenced by a number of factors affecting
pollen curves. A study was made about the reproductive biology of birch and environmental
factors infl uencing its pollen release and transport, in order to achieve a reliable
interpretation of Betula pollen curves. Aerobiological data were recorded in 2002 and
2003 at two sites in NW Spain and phenological observations were carried out on 20
trees from four Betula populations (three Betula alba L. and one B. pendula Roth.). Pollen
production was calculated for six Betula alba trees. Chilling and heat requirements
for triggering development were calculated. Due to differences in the geographical location,
budbreak and fl owering started fi rst in Betula pendula. The fl owering period lasted
from 8-13 days. Reduced pollen output per anther and catkin in individual trees in 2003
prompted a marked decline in overall pollen production. Major differences observed in
birch pollen curves were attributed to the infl uence both of weather conditions and pollen
transport from areas where the fl owering occurs at a different time. Heat requirements
calculated using phenological and aerobiological data were similar when the peak pollen-
count date was used.
