Pollen Dispersal in a Mountain Area
作者:
Vera Markgraf,
期刊:
Grana
(Taylor Available online 1980)
卷期:
Volume 19,
issue 2
页码: 127-146
ISSN:0017-3134
年代: 1980
DOI:10.1080/00173138009424995
出版商: Taylor & Francis Group
关键词: pollen dispersal;phenology;mountain area
数据来源: Taylor
摘要:
Atmospheric pollen, phenologic and meteorologic data collected during 12 intervals throughout one year in Tauber traps at different elevations allowed conclusions on vertical pollen dispersal in a mountain/valley system in the Niederhorn, Switzerland. Thus, pollen spectra at higher elevations near the timberline cannot be explained by dispersal through upslope winds but through gradient winds, i.e., winds from the general prevailing direction. The gradient wind direction lying perpendicular to the slope in consideration resulted in high elevation pollen spectra representing a regional aspect whereas the lower elevation spectra more or less faithfully recorded the local vegetation. High pollen numbers occur only during the respective local pollen production period. Secondary high pollen numbers related to precipitation maxima amount to about 10%, exceptionally 20% of the total annual pollen of the respective taxon. Thus, the washout of the pollen filtered in the vegetation seems to be of minor importance. Pollen production decreases quantitatively with increasing elevation, even for the same taxon and apparently independent from the actual growth density. This fact, combined with the regionality of the pollen dispersal at high elevation leads to a distortion of the near timberline pollen assemblages in terms of the local vegetation represented. Thus, lowland pollen dispersal mechanism cannot be used to explain pollen dispersal mechanism in mountain/valley systems.
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