70 research outputs found

    Effect of differentiated liming on the development of acidity of surface forest soil

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    On particular plots, 0, 1308, 2826, 3924 and 8478 kg/ha of fine limestone (grain size under 1 mm) was distributed by hands on the soil surface. Results are available for the forestry practice, research has to continue in the future -potential of negative liming impacts is topical here, consisting in humus mineralization and nutrients losses. Maximum effects on the soil reaction were observed in 8-10 years after limestone application at the soil surface (F -horizon) and in the period 10-15 years lower (H, A -horizons). Base saturation dynamics shows the time delay 2-4 years following pH values changes

    Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in Europe: an overview of management practices

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    Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), one of the most commercially important tree species in western North America and one of the most valuable timber trees worldwide, was introduced to Europe in 1827. It became a major species for afforestation in Western Europe after WWII, currently grows in 35 countries on over 0.83 million ha and is one of the most widespread non-native tree species across the continent. A lower sensitivity to drought makes Douglas-fir a potential alternative to the more drought-sensitive Norway spruce so its importance in Europe is expected to increase in the future. It is one of the fastest growing conifer species cultivated in Europe, with the largest reported dimensions of 2.3 m in diameter and 67.5 m in height. Pure stands have high productivity (up to 20 m3 ha-1a-1) and production (over 1000 m3 ha-1). The species is generally regenerated by planting (initial stocking density from less than 1000 seedlings ha-1 to more than 4000 ha-1), using seedlings of European provenance derived from seed orchards or certified seed stands. As the range of end-uses of its wood is very wide, the rotation period of Douglas-fir is highly variable and ranges between 40 and 120 years. When the production of large sized, knot-free timber is targeted, thinnings are always coupled with pruning up to 6 m. There is an increasing interest in growing Douglas-fir in mixtures and managing stands through close-to-nature silviculture, but the species’ intermediate shade tolerance means that it is best managed through group selection or shelter-wood systems

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