Facilitation is a positive interaction demonstrated to be one of the important factors shaping the regeneration niche of trees, mostly under stressful conditions which is currently studied in the frame of complex ecological networks. The protection provided by benefactor plants for tree seedlings playing the role of beneficiaries is documented mainly in arid and semi-arid habitats or in situations where herbivores’ pressure constitutes the main stressful factor for tree regeneration. One of the iconic Transylvanian landscapes is the wood-pasture, also one of the oldest agro-forestry systems to which recent forest expansion in abandoned agricultural fields or pastures is added. The proposed work represents a preliminary investigation on the association between benefactor plants, mostly spiny shrubs (Rosa canina, Crataegus monogyna, Prunus spinosa as the most frequently encountered benefactors) and tree seedlings (Quercus spp., Tilia spp., Carpinus betulus, Fraxinus angustifolia, Pyrus pyraster as most frequently encountered beneficiaries), in four different locations from North-Western and Western Romania, wood-pastures, abandoned pastures and abandoned agricultural fields under the consideration that the main stressful factor is represented by livestock grazing. Bipartite, qualitative merged network was generated depicting the interaction between beneficiaries and benefactors. Commonly used metrics were calculated: connectivity, nestedness, modularity, betweenness centrality and centralization compared to similar facilitation networks presented in the literature. Facilitation network is characterized by high nestedness (N=0.896), lack of modularity, relatively high connectance (C=0.233), features encountered in mutualistic networks also. Betweenness centrality scores highlighted the keystone benefactor and beneficiary species, while betweenness centralization score (0.192) indicates the fact that there are several species sharing the dominant position in terms of interactions. The analysis of measurement data (seedlings’ and benefactor plants’ heights, distance from focal seedlings to nearest benefactor species and orientation) showed that there is common pattern in orientation (most of the benefactor species oriented toward South or South West) also in dimensional variability (MANOVA results).

Seedlings are the foundation for many terrestrial ecosystems and are a critical consideration and investment for implementing global forest and landscape restoration programs. Global leaders have pledged to restore millions of hectares during the next decade, necessitating many millions of established plants. Although natural regeneration and direct seeding will likely meet a portion of that need, large quantities of high-quality, nursery-grown seedlings are also required. Insufficient plant quantities or poor-quality plants result in unsuccessful outplanting programs. Such failures have considerable economic and environmental consequences and will result in an inability to meet restoration goals. Nonetheless, the importance of restoration nurseries is often overlooked when making large-scale restoration commitments. Technology already exists to produce high-quality plants to meet a variety of goals. This technology cannot be applied, however, unless adequate resources and training are made available by overcoming political and socioeconomic barriers. In this article, we discuss the important role of nurseries to meet global restoration commitments and review three case studies where increased support to nursery programs resulted in improved restoration success.

During a three-year survey in 14 forest nurseries in Serbia we measured seedlings of 19 species and 96 stocktypes of both conifers and broadleaves. Seedlings were measured in the nurseries for height and diameter, and subsamples was taken for measurements of shoot and root dry weight, and presence of mycorrhiza. Results of mean values and variation of measured morphological attributes are presented and compared to Serbian standard for seedlings quality. We found mycorrhiza on seedlings root from almost every nursery, seedbed and tray. Our results show that current nursery cultural practice need to be improved and that seedlings quality standards should be updated.

The history of reforestation in Slovakia is long and rich; from reforestation by seeding, through the small forest nurseries, reforestation of extreme degraded and high-mountain sites to the current The Act on forest reproductive material, nursery centers and reforestation of large windthrow areas. After brief introduction of the history, rather large part of this review is dedicated to the current nursery and especially reforestation practices – planning, pre-planting site preparation, seeding and planting techniques, post-planting care, monitoring of planting performance. Recent nursery and planting research activities are given very shortly. Perspective nursery (e.g. improvement of seedlings’ quality by inoculation with beneficial microorganisms, vegetative propagation) and reforestation treatments and practices (e.g. the use of larger amount of container-grown seedlings, application of hydrogels and ectomycorrhizal fungi, progressive seeding technique, underplanting) are relatively in detail but of course not comprehensively discussed finally. Despite of the lack of a complex reforestation strategy and current and possibly future financial sources and personnel limitations, the introduced perspective practices should contribute to successful solution of reforestation challenges following from endangering the forests by climate change. 

Preserving forest legacy was an important objective throughout Romanian history and so is today. Artificial forest regeneration (including both reforestation and afforestation) was widely used to ensure the forest continuity, following forest harvesting, or to create new forests on non-forest lands. As Romania has undergone various political changes that affected the socio-economic environment, these changes also left significant marks on forest cover dynamics. In this paper, we chronologically present the historical initiatives to preserve and increase forest cover in Romania, the current practices, available funding and future perspectives on artificial forest regeneration. Increasing forest cover from the current level of 27% to, and beyond European average of 33% seems an ambitious target for Romania. However, that may be achievable if the sources of funding for afforestation would diversify and increase, the available funds would be more effectively accessed, national forestry regulations would be less bureaucratic and the guidelines on artificial forest regeneration would be up to date and less restrictive. The whole framework of forestation should be revised to comply with recent social, economic and environmental realities, and modern criteria and indicators for sustainable forest management should be explicitly included. The new goals should also be tailored to the changes regarding the property type, climate related trends and new requirements of the forest certification systems.

Turkey has 9.64 million hectares of unproductive forests 43% of the total forest area according, to 2016’ forest inventory. Forest establishment including afforestation, reforestation, rehabilitation and private plantation is the most important method to convert unproductive forest into productive ones, and also to increase present productivity of product forest by improved seed and seedling materials. Turkish forest establishment is examined based on past, present, and future perspectives according to forest inventory from 1946 to 2015 in the present study to contribute present and future establishment. 

The historical development of afforestations in Bulgaria was investigated. Some of the more important decisions and events which determine the correct state policy in the field of afforestations are pointed out. The most significant achievements are in: erosion control, incl. water tank protection from silting up; increasing the tree volume and forest growth; protection of agriculture via forest protection belts; landscape improving. The social importance for more employment and improvement of means of livelihood is mentioned. Proved reasons for decreasing the afforested areas since 1980s are given. The main mistakes and problems are mentioned as well as the changes in the afforestation policy and future challenges.

The experiments were led to study the effect of pretreatments and their duration on germination behavior of three Acacia species A. cyanophylla Lindl., A. farnesiana L. and A. decurrens Willd. by analyzing three parameters (GP: germination percentage; MGT: germination mean time (days) and GRI: germination rate index) for various times of incubation (5, 10 and 15 days) in Petri dishes. Pre-sowing treatment included immersion in concentrated sulphuric acid for 60, 90 and 120 minutes. The sowing in distilled water (Control) had no positive effect on the germination induction. Generally, the seed pretreatments were very useful to improve germination. Time of immersion significantly (P < 0.0001) affected GP, MGT and GRI in all species. Increasing the duration of sulphuric acid immersion (from 60 to 120 min) improved the germination percentages for A. cyanophylla and A. farnesiana seeds to (98% and 99%), respectively. However, increasing this duration had a negative effect on A. decurrens seed germination, reducing the final germination percentage from 97% at 60 minutes of immersion to 43% at 120 minutes.

Two pH experiments were conducted at a sandy, bareroot loblolly pine (Pinus taeda L.) nursery in Texas. A sulfur trial (0, 813, 1626, 2439 kg ha^-1 of elemental sulfur) was installed to determine if lowering soil pH would result in nutrient toxicity symptoms and affect seedling morphology. Although soil acidity in the sulfur study ranged from pH 3.9 to pH 5.0, none of the treatments resulted in micronutrient toxicity and none affected height growth, root-collar diameter, root mass, shoot mass or the root-mass ratio (root dry mass/total dry mass). Acidifying soil with sulfur increased leaching of calcium, potassium, magnesium, manganese and zinc but there was no effect on seedling morphology. The objective of the liming trial (0, 813, 1626, 3252 kg ha^-1 of dolomitic lime) was to determine if increasing alkalinity would result in an iron deficiency and reduce seedling growth. As expected, applying lime increased the calcium and magnesium levels but had no effect on soil levels of iron, phosphorus, potassium, sulfur, zinc and sodium. However, the root-mass ratio was reduced by applications of dolomitic lime (pH ranged from 5.3 to 6.0). Differences in soil properties (i.e. plot location) had a greater effect on seedling morphology than lime applications. Foliage levels of manganese and boron were reduced by the highest rate of lime and sulfur, respectively.

Direct seeding has been considered a forest restoration option for centuries. Over the past half century, the use of this practice has declined in developed countries as forest regeneration programs have advanced with the production of quality seedlings that can successfully establish restoration sites. Direct seeding is being reconsidered as a restoration option as the potential size of the worldwide forest restoration program has grown because of massive deforestation in third-world nations and due to global climate change. This review examines direct seeding from a number of perspectives. First, merits of using this practice in restoration programs are defined. Major merits of this option are that it can be done quickly, over hard to reach and large disturbed areas, and at a relatively low cost. Second, current research findings from restoration programs are discussed. The major finding is that seedling establishment rates are low (i.e. typically around 20% of seeds planted) due to site conditions, seed predation and vegetation competition, and field performance (i.e. survival and growth) is lower than planted seedlings. Third, operational practices for the application in restoration programs are reviewed. To successfully conduct direct seeding programs practitioners need to consider seedbed receptivity, seed distribution and seeding rate. Fourth, potential new practices are presented. Some of these new practices attempt to create a more effective means to disperse seed across the site, minimize seed predation or create a more favorable microsite environment. This review provides a synthesis of what is known about direct seeding, thereby allowing practitioners to make a rational decision of whether to apply this practice towards their forest restoration program.