Potential of Douglas­‑fir as a partial substitute for Norway spruce – review of the newest Czech literature

Abstract

Presentation summarizes the results concerning the effects of cultivation of Douglas­‑fir (Pseudotsuga menziesii /Mirb./ Franco), especially in the last decades, on the intensity of production as well as non­‑production forest functions in the conditions of the Czech Republic. It analyzes the research outcomes from the point of view of volume and value production in comparison with other native tree species, from the point of view of the soil effects and effects on the ground vegetation diversity, and from point of view of stability and cultivation in the last period. Main aim is represented by the comparison with the Norway spruce, which can be with advantages replaced by this species, with favourable impact on amount and value of the timber production, on the soil and biodiversity status of the ground vegetation. Also the stability of forest stands can be supported considerably. Douglas­‑fir represents favourable alternative to the Norway spruce in lower and middle altitudes and it can contribute highly to the competitiveness of the Czech forestry.

Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south‐western Germany

“…This may indicate where in the landscape the native species performs better than the exotic one and vice versa. Although there is some evidence, especially for silver fir, that these species might be more drought tolerant than spruce (Bouriaud & Popa, ; Chen, Welsh, & Hamann, ; Desplanque, Rolland, & Schweingruber, ; Kowalik, Borghetti, Busoni, Sanesi, & Vendramin, ; Lebourgeois, Rathgeber, & Ulrich, ; Nothdurft, Wolf, Ringeler, Böhner, & Saborowski, ; van der Maaten‐Theunissen et al., ), few studies compare drought tolerance of these three conifer species in Europe (Boden et al., ; Bouriaud & Popa, ; Feliksik & Wilczyński, ; Kantor, ; Podrázský, ; van der Maaten‐Theunissen et al., ). Moreover, these studies have been carried out mostly at small spatial scales (individual stands, or sites with extreme climatic conditions), and are thus not suitable to extrapolate the results larger scales.…”

Is the quality of the non-native Douglas-fir wood produced in the Czech forests comparable to native softwoods?

“…Interest in Douglas-fir was triggered mostly by the high wood production volume of the non-native species noticed in Europe and New Zealand (Ledgard and Belton 1985;Greguš 1996;Remeš and Zeidler 2014;Podrázský et al 2016). Furthermore, its apparent adaptive ability to various sites and climates (Bormann 1960;Lausberg et al 1995;Zhang and Hebda 2004;Beedlow et al 2013;Ruiz Diaz Britez et al 2014) prompted the idea of replacing native European species with Douglas-fir (Augusto et al 2003;Menšík et al 2009;Kantor and Mareš 2009;Kubeček et al 2014;Remeš and Zeidler 2014;Podrázský 2015;Podrázský et al 2016;Blohm et al 2016).…”

“…Nowadays, it is suggested that Douglas-fir potentially can contribute a larger share of the productivity of Czech commercial forests by partly replacing the native Norway spruce (Podrázský et al 2013). Practically, until today, several articles have been supporting this idea, based on environmental parameters (drought tolerance, soil quality) and the high production volumes (Menšík et al 2009;Viewegh et al 2014;Kubeček et al 2014;Podrázský 2015). Nevertheless, there is still only a limited number of reports on the quality of the Douglas-fir wood produced in the Czech Republic (Hapla and Knigge 1985;Hapla 2000;Remeš and Zeidler 2014) which can hardly provide enough information on the properties of the produced timber in the country.…”

The effects of Douglas fir monoculture on stand characteristics in a zone of Montane beech forest

“…Not enough is known of how these introduced species affect the soil and biogeochemical cycle of nutrients through soil horizons [36]. Examinations of the effects of substitution of spruce and black pine by pure and mixed stands of Douglas fir on soil characteristics have revealed that the influence of this exotic species on soil chemistry, organic matter and nutrient dynamics is more favorable than other coniferous species [24,34,37,38]. Namely, it has been shown that Douglas fir acidifies the upper soil layers to a lesser extent and contributes to the creation of more favorable forms of humus compared to spruce.…”