Silver fir (Abies alba Mill.) is one of the most valuable conifer trees in Europe for historical and economic reasons. Growing interest in the species, along with the recognition that silver fir was subjected to inappropriate silvicultural measures during the 20th century due a lack of understanding of its ecology, have spurred recent studies from various disciplines which have yielded new insights into the gene ecology, history, ecology, structure and dynamics of fir populations. In this paper, we provide a multidisciplinary, synoptical review discussing the prospects for silver fir forestry in the 21st century. We describe the main characteristics of the history and ecology of silver fir, with a particular emphasis on gene ecology and the structure and dynamics of fir populations with respect to mixed stands and fir management. Fir is a fundamental species for maintaining high biodiversity in forested ecosystems because of its shade tolerance, plasticity to environmental conditions and ability to coexist with many tree species. Silver fir ecotypes show remarkable variation in features such as frost hardiness, drought resilience and shade tolerance. Fir can create stands of heterogeneous stand structure, from one-storied through to multi-storied structure and finally to selection structure. Natural regeneration of fir will be scarce if fir stands are managed inappropriately through the application of clear cutting, a short regeneration period and abrupt removal of shelter trees. Climate change is expected to reduce the abundance and distribution range of silver fir. Improvements in forest management treatments are recommended to improve silver fir conservation.

European ash (Fraxinus excelsior L.) is common throughout much of Europe and is a valuable broadleaved tree due to its ecological characteristics, outstanding wood properties and high economic value. It is a fast growing species, associated with several forest types and with a scattered distribution in many different forest communities. In this review, we sum up essential characteristics of European ash, relevant to the further development of silvicultural practices. The paper covers site requirements, regeneration and stand establishment, growth dynamics and wood quality, and health and robustness. The review also highlights implications for silviculture and summarizes new information on ash dieback, a phenomenon which is observed in many European countries. Ash grows best on fertile, pH-neutral, deep, freely drained soils and such sites should be favoured if the aim is for high quality timber. Ash grows well at wide spacing which can result in enlarged ring width and increased latewood percentage, making the wood denser and stronger. Relatively short rotations may be recommended, depending on site, to avoid black heart: for example, a harvesting diameter of 60 cm can be reached within 60–75 years at 60–80 ash crop trees per ha. Universal recommendations are therefore for wide spacing with heavy, regular thinning in order to get a large diameter within a relatively short rotation. The necessity for pruning depends on the stand density at establishment and the subsequent thinning regime.

In the context of global change, the integration of non-native tree (NNT) species into European forestry is increasingly being discussed. The ecological consequences of increasing use or spread of NNTs in European forests are highly uncertain, as the scientific evidence is either constraint to results from case studies with limited spatial extent, or concerns global assessments that lack focus on European NNTs. For either case, generalisations on European NNTs are challenging to draw. Here we compile data on the impacts of seven important NNTs (Acacia dealbata, Ailanthus altissima, Eucalyptus globulus, Prunus serotina, Pseudotsuga menziesii, Quercus rubra, Robinia pseudoacacia) on physical and chemical soil properties and diversity attributes in Europe, and summarise commonalities and differences. From a total of 103 publications considered, studies on diversity attributes were overall more frequent than studies on soil properties. The effects on soil properties varied greatly among tree species and depended on the respective soil property. Overall, increasing (45%) and decreasing (45%) impacts on soil occurred with similar frequency. In contrast, decreasing impacts on biodiversity were much more frequent (66%) than increasing ones (24%). Species phylogenetically distant from European tree species, such as Acacia dealbata, Eucalyptus globulus and Ailanthus altissima, showed the strongest decreasing impacts on biodiversity. Our results suggest that forest managers should be cautious in using NNTs, as a majority of NNT stands host fewer species when compared with native tree species or ecosystems, likely reflected in changes in biotic interactions and ecosystem functions. The high variability of impacts suggests that individual NNTs should be assessed separately, but NNTs that lack European relatives should be used with particular caution.

The paper describes the structure, growth and vitality of natural oak regeneration in relation to stand density. To gain a better understanding of regeneration strategies, the investigation was carried out in oak forest flood plains in Poland, which were flooded in the summer of 1997. To study the stand structure and regeneration, 108 circular plots were established in stands managed using the shelterwood system. In addition, five gaps were chosen in a stand managed using the group cutting system (Legnica forest district). The results of the study showed that oak regenerated spontaneously in all stands. The abundance and vitality of oak seedlings and saplings were very high. The number of oak seedlings and saplings significantly depended on stand density. The greatest maximum height was found in gaps (146.0 cm) and in a stand with open canopy (88.9 cm) in Wołów. In Wołów and Miękinia, the shortest oaks grew in the worst light conditions. To regenerate naturally, oak stands in preparatory cutting should be reduced in the number of trees per hectare to ∼150 and decreased in basal area to ∼26 m² ha⁻¹. The group cutting system can be used in oak stands growing on flood plain sites, but there is the danger of ground vegetation development in openings.