Structure and silvicultural demands of some narrow-leaved ash stands in the area of the Special Nature Reserve "Gornje Podunavlje"

Abstract

The structure and silvicultural demands of two narrow-leaved ash stands of different origin and age was studied in the Special Nature Reserve "Gornje Podunavlje", in the area protected against floods. The elements of growth and structure in the 38-year-old natural stand in the area of previous wet depressions (dg=24,0 cm, dg20%=33,4 cm, hL=26,1 m, hg20%=27,65 m, N=745 kom·ha-1, G=33,81 m2·ha-1, V=433,3 m3·ha-1), and in the 74-year-old artificial stand on the site of the forest Fraxineto-Ulmetum effusae Slav. 1952 (dg=48,8 cm, dg20%=63,9 cm, hL=35,5 m, hg20%=36,7 m, N=288 kom·ha-1, G=53,86 m2·ha-1, V=842,30 m3·ha-1) point to very high production effects. The diameter distribution of trees is characterised by slight skewness and low kurtosis, and the height distribution of trees is characterised by left skewness. 154 future trees per hectare were selected in the 38-yearold stand, and in the twice older stand with the same initial selection criterion, the number of future trees per hectare was 82. The stands were treated by selection thinning of moderate weight (25% per G), i.e. low thinning based on qd=0.83-0.85. Thinning volume amounted to 109.8 m3·ha-1 in 38-year-old stand, and 207.4 m3·ha-1 in the 74-year-old stand.

Keywords

• Fraxinus angustifolia Vahl
• Nature Reserve "Gornje Podunavlje"
• alluvial plain forests
• stand structure
• silvicultural demands