Růst douglasky tisolisté v mlazinách v závislosti na výchově a konkurenčním tlaku borovice lesní na živinově chudších stanovištích

Abstract

The article focuses on the growth response of young stands of Douglas-fir and mixtures of Douglas-fir with Scots pine on nutrient-poor sites. The experiment was established in a seventeen-year-old naturally regenerated stands using a block design with two replications. The silvicultural intervention (thinning) involved reducing the number of trees to 1,800 per hectare in the stand without pine representation and reducing it to approximately 4,000 trees in the less mature stand in the mixture with pine. The results of a thirteen-year time series since the implementation of the initial thinning are presented. The diameter growth of Douglas-fir on these sites is significantly lower compared to Scots pine. Without thinning, Douglas-fir is gradually being displaced by Scots pine in the stand, leading to a decrease in its representation and basal area. The silvicultural intervention have positively influenced diameter increment and improved the static properties of the trees, as expressed by their height-diameter ratio (HDR). In the thinned plot without pine occurrence, it was even possible to temporarily reduce the HDR values of target Douglas-fir trees. In the thinned plot with pine competition, the rate of HDR increase was only reduced compared to the control.