Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

A stand with Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) and Sitka spruce (Picea sitchensis (Bong.) Carr.) in Obştea Sălişte Forest District (Vâlcea County).


The paper shows the results of inventory works carried out in a stand (sub-compartment 34B, Working Cercle I Sălişte, Obştea Sălişte Forest District) comprising Douglas-fir (DF) and Sitka spruce (SS, a non-native tree species very seldom used in Romania), established by planting (1.5 × 1.5 m) in 1962 complementary to the natural regeneration of European beech. At 60 years of age, Douglas-fir behaves better than Sitka spruce in biommetrical terms and the most relevant characteristics of the two species are as follows: - maximum diameter at breast height: 67.1 cm (DF) vs. 37.7 cm (SS); - quadratic mean diameter (QMD): 41.81 cm (DF) vs. 27.43 cm (SS); - maximum height: 39.5 m (DF) vs. 30.5 m (SS); - height corresponding to the QMD: 32.00 m (DF) vs. 24.95 m (SS); - mean slenderness (stability) index: 84 (DF) vs. 90 (SS); - mean crown diameter: 462 cm (DF) vs. 361 cm (SS); - both species show a defective natural pruning as in other stands established throughout Europe. Douglas-fir has adapted to the local conditions as in many parts of Romania, where it covers ca. 12,700 ha, and shows a high wood production potential. Sitka spruce has been able to survive under difficult local ecological conditions (e.g., high elevation, temperate-continental climate, very different from the oceanic climate in the native range and on the northern and western coasts of Europe), without producing as much wood as in other European countries such as the UK or Ireland.