Thinning experiments in Norway spruce stands after 40 years of investigation – 1st series
M. Slodičák, J. Novákhttps://doi.org/10.17221/4681-JFSCitation:Slodičák M., Novák J. (2003): Thinning experiments in Norway spruce stands after 40 years of investigation – 1st series. J. For. Sci., 49: 45-73.
Forestry and Game Management Research Institute at Jíloviště-Strnady has created a new experimental base for thinning research since 1956. A total of 46 experimental series were founded in Norway spruce (Picea abies [L.] Karst.); 24 series are still maintained. This paper focuses on the series established in young Norway spruce stands in 1958 (Rumburk, Mostek, Vimperk I, Vimperk II and Nisa). The goal of thinning experiment was to compare two basic methods of thinning: positive selection from above (2a) and negative selection from below (3b or 5b). Each experimental series has a control plot (1c) where no thinning was conducted. The effect of thinning by positive selection from above carried out in the 40-year period of investigations was a 10–45% decrease in the abundance of trees in lower diameter classes compared with control plots. Negative selection from below resulted in a more pronounced decrease in thin trees abundance (50–69% compared with control plots). The abundance of thick trees (diameter of 30 cm and more) increased by 5–50% on all comparative plots with thinning. Static stability characterised by the h/d ratio of mean stem and h/d ratio of dominant trees (200 thickest trees per hectare) was influenced by thinning mostly positively (final value of h/d ratio found by the last revision was considerably lower).Keywords:
positive selection from above; negative selection from below; thinning; Norway spruce