The aim of the article is to assess the significance of a solitary find of a Roman bronze barrel-shaped bucket and a handle from another bronze vessel. Besides a necessary artefactual analysis, the ...authors also pay attention to palynological findings and mainly to the interpretation of the find, whose location on a spur above the river Dyje is unusual, without any confirmed relations to the surrounding barbarian settlement from the Roman Period.
Influence of snow damage on aerodynamic characteristics of a spruce stand Hurtalová, T., Slovak Academy of Sciences, Bratislava (Slovak Republic). Geophysical Institute; Matejka, F., Slovak Academy of Sciences, Bratislava (Slovak Republic). Geophysical Institute; Janouš, D., Academy of Sciences of the Czech Republic, Brno (Czech Republic). Institute of Systems Biology and Ecology ...
Folia oecologica,
2007, Letnik:
34, Številka:
2
Journal Article
Recenzirano
Influence of snow damage on aerodynamic characteristics of a spruce stand was investigated during the growing seasons 2005 and 2006 before and after the winter 2005/2006 that caused damage to the ...forest. With this aim, the wind speed profiles measured in and above the investigated forest stand were analyzed. This forest is situated in the Experimental Ecological Study Site Bílý Kříž in the Moravian-Silesian Beskydy Mountains, the Czech Republic. The experimental site consists of two plots with Norway spruce monocultures with different stand densities. In the growing season 2005, the mean tree height was 11.9 m on the dense plot (Fd; a density of 2,044 trees/ha) and 11.0 m on the sparse one (Fs; a density of 1,652 trees/ha). The measurements of wind speed profile were realized at six levels on 26-m-high towers situated near the centre of each plot. The winter 2005/2006 was characterized by continuous snow cover (from November 2005 to April 2006) with a high water value in the investigated locality. The damage to the forest caused by this snow blanket was noticeable, mainly in Fd. The stand density decreased by about 29% on Fd and by about 14% on Fs plot. It witnesses entirely new airflow conditions within and over this forest stand and connected changes in its aerodynamic characteristics.
Evaluation of global radiation was performed at the study site of Bily Kriz (the Moravian-Silesian Beskids Mts, the Czech Republic) during the growing seasons (May-October) in 1991-2000. Radiation ...conditions were characterized by daily and monthly sums of global radiation. Detailed analysis of global radiation daily sums revealed that they vary considerably with time. Average value of global radiation daily sums calculated after the whole period of seasons 1991-2000 was 13.49 MJ per square m. While seasonal course of monthly averages of global radiation daily sums corresponded to the changes of sun elevation, the average monthly sums of global radiation did not. Average seasonal sum of global radiation at the study site in 1991-2000 was 2483 +/- 141 MJ per square m. Relationship between global radiation daily sums at the Bily Kriz study site and sunshine duration at the nearby site of Lysa hora was described and linear relationship between these two characteristics was confirmed. On the basis of this determined relationship it was possible to reconstruct global radiation daily sums at the study site for a period of forty years (1961-2000). Average of global radiation daily sums calculated for the whole period of seasons from 1961 to 2000 was 9.11 MJ per quare m. The highest monthly averages of global radiation daily sums were found in June and July, the lowest in October. It was confirmed that average monthly sums of global radiation did not correspond to the sun elevation even for the long period of 1961-2000. Average seasonal sum of global radiation was 2415 ñ 152 MJ.m-2 in 1961-2000. On average, 40% of extra-terrestrial solar radiation reached the study site during the growing season in 1961-2000
The results of the microclimatic profile measurements obtained in Moravian-Silesian Beskids at Bily Kriz (898-908 m a.s.l.) were evaluated with the aim to analyse and quantify the microclimatic ...conditions at an interface between the young Norway spruce forest and the surrounding atmosphere. The zero plane displacement, roughness length and drag coefficients were compared with the corresponding values for other surfaces. It was found that during the well-lighted part of a day the maximum air temperature level occurs in the lowest part of the canopy or near the soil surface. However, as to the vertical distribution of air humidity, the existence of two sources of water vapours is evident. One of these sources is created by the soil surface and the second is located in the upper part of the canopy where the most intensive transpiration is going on
The present status of the research on the microclimate of forest stands is reviewed in relation to changing objectives of this interdisciplinary scientific activity and research priorities are ...identified. This contribution presents a selected overview of the current status together with a projection of the future needs for the research in the field of the forest meteorology and climatology
PDF
