Natural Environment Monitoring 2009, No 10, pp. 65-72
DETERMINING THE ROLE OF FOG DEPOSITS AS CONDITIONERS
OF THROUGHFALL VOLUME
In the central part of the Świętokrzyskie (Holy Cross) Mountains, tree stands affect throughfall transformation considerably. On average, in the years 2000-2008, throughfall in the beech stand amounted to 75.2 %, and in the fir-beech stand – to 74.1% of bulk precipitation, displaying considerable seasonal variation. From October to March, cases of throughfall exceeding bulk precipitation volume were recorded. The cause of this phenomenon is the so-called fog deposits.
The results of studies into spatial distribution of precipitation which penetrates tree crowns draw special attention to areas right below fir tree crowns, which receive markedly larger amounts of water than the areas below beech crowns. Undoubtedly, the reason for this distribution is an additional source of precipitation which is, as already indicated, fog deposits. The highest volume of precipitation was recorded below crown edges where the average values obtained accounted for over 176 % of bulk precipitation. The lowest precipitation, under 70 %, was recorded next to the trunk and below the central part of beech crowns. This phenomenon is referred to as “the umbrella” in fir trees and “the funnel” in beech trees.