The Serbian spruce (Picea omorika (Panč.) Purk.) is an endemic tree species from the Balkan Peninsula, which also thrives in Slovenia, and would be an interesting minority alternative to the Norway spruce (Picea abies (L.) H. Karst.) on some sites. This study was carried out on a Serbian spruce plantation below the hill Počivalnik, between Unec and Postojna. The trees were planted in 1988 and are currently classified as pole stand. We have measured the diameters of the trees and systematically evaluated the vitality of each tree throughout the plantation. Data processing consisted of calculating the percentage of trees of each health status for each provenance and phenotype present in the plantation, creating a plantation model, analysis of variance and Tukey's post-hoc test. We found that the provenances have a significant effect on the vitality of the trees, but not on the tree diameter. Phenotypes affect both the vitality of the trees and the tree diameter. The correlation between phenotype and tree diameter is significant within phenotypes B (type 'semidichotomy') and C (type 'serbica'). Also the impact of phenotypes on diameter increments varies between the different provenances. According to our investigations, the most suitable seed material is from the Šargan provenance (read Shargan). In terms of phenotype, C (type 'serbica') and F (type 'argentea') seem to be the most suitable. They are also the most desirable for horticultural use.
COBISS.SI-ID: 37851907
Europe has a history rich in examples of successful and problematic introductions of trees with a native origin outside of Europe (non-native trees, NNT). Many international legal frameworks such as treaties and conventions and also the European Union have responded to the global concern about potential negative impacts of NNT that may become invasive in natural ecosystems. It is, however, national and regional legislation in particular that affects current and future management decisions in the forest sector and shapes the landscapes of Europe. We identified all relevant legal instruments regulating NNT, the different legal approaches and the regulatory intensity in 40 European countries (no microstates). Information on hard and effective soft law instruments were collected by means of a targeted questionnaire and consultation of international and national legislation information systems and databases. In total, 335 relevant legal instruments were in place in June/July 2019 to regulate the use of NNT in the investigated 116 geopolitical legal units (countries as well as sub-national regions with their own legislation). Countries and regions were empirically categorized according to ad hocdefined legislation indicators.
COBISS.SI-ID: 19917315
Black walnut (Juglans nigra L.) is a light-demanding, competition-intolerant, and tall forest tree species, introduced in Europe from North America at the beginning of the seventeenth century. It has an important economic role in Europe for producing wood and fruits, in agroforestry systems, as an ornamental tree for parks and avenues, for rehabilitation/restoration of degraded lands. The best sites for black walnut growth have warm and mild climates, with frequent and well-spread precipitation, and rich, deep, near neutral, well-drained and moist soils. Black walnut is a fast grower in youth and its height and diameter growth reach their peaks before age 30–35 years. It is globally the best known allelopathic species due to the juglone substance present in all parts of black walnut trees. The species is storm-resistant and not affected by any major pest or disease in Europe. It is regenerated by planting or direct seeding on bare land, in monocultures and mixed stands. The management of stands with black walnut, with a rotation period generally up to 80 years, include weeding (mandatory), cleaning-respacing (in dense stands), thinning (mostly from above), high and formative pruning (mandatory), with the aim of producing valuable wood for sliced veneer, solid furniture, flooring/parquet, cabinetry, panelling, sculpture, musical instruments, gunstocks.
COBISS.SI-ID: 16744195