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.

The forest has always played a big part in Belarus. At present it covers about 40% of area of the country`s territory. Predominantly the forests are of natural origin. The main species are Pinus sylvestris L. (Scotch pine), Betula pendula Roth (European white birch) and Picea abies (L.) Karst. (Norway spruce). The other valuable species are Quercus robur L (English oak), Alnus glutinosa (L.) Gaertn. (European alder), Larix decidua Mill. (European larch), Abies alba Mill. (Silver fir). The history of the forest management in Belarus showed that over last 150 years the enormous damage to the qualitative and quantitative composition of forests had been made by wars and reconstruction of destroyed industry. The taken reforestation measures allowed to increase the forest area significantly, however, the work on improving of forests` quality requires further development. At present the artificial forest regeneration prevails in the republic. Over the past five years the volumes of established forest plantations range from 21 to 25 thousand hectares annually, the areas of assistance to the natural regeneration - from 4 to 6 thousand hectares annually. By now there are about 1,700 ha of the forest seed orchards, 2,795 plus trees and 1,125 ha of the plus stands in the republic. The cultivation of planting stock for needs of reforestation is carried out on 73 forest tree nurseries with a total area of 1,440 ha. Annually over the last five years there were grown from 270 to 317 million seedlings and transplants, among them 30-35 million seedlings were grown in greenhouses and about 6 million were container seedlings. In order to improve the gene resource and thereby to increase the productivity and quality of future forests, the tendency of forest plantations` prevalence in the reforestation process of Belarus should remain, but in this case the volumes of partial forest plantations should be increased.

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. 

Serbian spruce (Picea omorika (Pančić) Purk.) is a rare and endangered tertiary relict and endemic species, with restricted and fragmented natural range in Serbia and Bosnia and Herzegovina, mainly around the mid-course of the Drina river. Since the middle of the 19th century, its natural range declines constantly, followed by a decline in the number of mature individuals. The decline of this forest species is slow and mainly attributed to poor regeneration and low competing ability. Given the foreseen worsening of the climate in forthcoming decades, this decline can only accelerate. In recent years, dieback related to drought has been observed as response to extreme weather events suggesting that Serbian spruce will face difficulties in adapting to climate change within its natural range. However, successful use of Serbian spruce in Central and Northern Europe indicates potentially large adaptive potential of this species which, along with the high genetic variability, outweigh the limited morphological variation, self-fertilization, and limitations related to the restricted natural range in the first place, and, indicates possible directions of migration in the second place. In this paper, current conservation actions are discussed, and strategies for the species survival in a changing environment are suggested. Since migration and adaptation are the least likely responses of this species to climate change, measures such as assisted migration may be the only strategy which will enable persistence of Serbian spruce. Current conservation programs, limited to in-situ actions, need to be supplemented with ex-situ actions and strategies. In the worst case scenario, i.e. for species such as Serbian spruce which are unable to migrate and/or adapt to changing climate, the most suitable sites should be identified and colonized in order to prevent extinction in the near future.

Surface mining causes major destruction of natural landscapes and ecosystems. The most fertile, surface soil layer is lost permanently, together with vegetation, wildlife, and micro flora. Post-mining areas are characterized with diverse edaphic, topographic, hydrographic conditions, which complicate land restoration. Successful establishment of forest ecosystems on such land depends mostly on selection of tree species. The chosen plants must be capable of tolerating a wide range of acidity, fertility, moisture, and have potential to ameliorate such substrates for more demanding species. But, reforestation of heavily damaged ecosystems, such as post-mining areas, demands a new approach in seedlings production. This new approach takes into account specific requirements of habitat and integrates them into “targeted production of planting material”. A good strategy for successful reforestation of post-mining areas is the input of organic matter (compost, mulch). Also, current knowledge and experiences emphasize the potential of beneficial microorganisms such as, mycorrhizal fungi (MF) and plant growth promoting rhizobacteria (PGPR). The majority of studies that deal with beneficial interactions between trees and microorganisms are focused on the mycorrhiza, while plant growth promoting rhizobacteria are less present in silviculture. In this study, the focus is on the reforestation challenges of two mining basins, Majdanpek and Kolubara and suggests beneficial microorganisms as potential solution. The study presents results of several years’ researches on plant response to the presence of mycorrhizal fungi and PGPR. The substrates used for plant growth were Majdanpek and Kolubara mine deposals. Mycorrhizal seedlings were grown in Majdanpek mine deposal, and at the end of the experiment they had 30% higher biomass in comparison to control (seedlings without mycorrhiza). Seedlings linked with fungi had a higher survival rate. Deposals from Kolubara Mining Basin were used as a substrate for seedlings inoculated with PGPR. In the first experiment, Scots pine and Norway spruce were inoculated with Azotobacter chroococcum, Bacillus megaterium, B. circulans, B. licheniformis, B. pumilus, B. amyloliquefaciens. Inoculation resulted with higher biomass production (Scots pine 43%, Norway spruce 34%). Similar results were obtained in the second experiment where Scots pine and black locust were inoculated with Bacillus licheniformis, Aeromonas hydrophila, Pseudomonas putida and Burkholderia cepacia. Both species had higher biomass (around 20%) in comparison to un-inoculated control. The results confirmed the fact that early establishment and successful growth of vegetation on devastated areas depends on the presence and activity of soil microbes. Microorganisms as a “nature’s solution” pose the potential to alleviate reforestation challenges of anthropogenic devastated landscapes. Their presence and activity is crucial for ecosystem stability. In areas with compromised balance, their introduction is justified action for achieving the goal of long term ecosystem sustainability. 

This study was carried out to compare quality and morphology in 1+0 year containerized seedlings of Turkish red pine (Pinus brutia Ten.) originating from a seed stand and a seed orchard based on height and root-collar diameter. Averages of seedling height and root-collar diameter were 13.8 cm and 2.63 mm in orchard seedlings, while they were 14.8 cm and 4.56 mm in stand seedlings, respectively. There were significant differences (p≤0.05) between seed sources for the characters according to result of ANOVA. Stand seedlings were better quality than that of orchard seedlings according to quality classification of Turkish Standard Institute. Positive and significant (p≤0.05) relations were found between the characters in both seed sources based on results of correlation analysis. Results of the study were discussed for nursery practices, plantation forestry, and genetic-breeding of the species. 

Involvement in forest restoration programs across North America for the past 40 years, dealing with nursery cultural practices, operational seedling quality programs and defining seedling performance on restoration sites has given me a unique perspective, which I have used to examine programs from both a research and operational perspective. Certain biological patterns and themes continually appeared across these programs and this paper discusses five of the most common themes.

Learning To Think Like a Tree – It is important for practitioners to develop an understanding of the ecophysiological performance of tree species in a nursery or forest restoration program in order to understand how seedlings grow. This understanding leads to sound biologically based cultural decisions to improve seedling performance.  

Stress and the Cyclical Nature of Stress Resistance – Seedlings are exposed to stress when environmental conditions limit their performance. Plants develop physiological resistance attributes to mitigate stress and these attributes change throughout the seasonal cycle. Practitioners have developed hardening cultural practices that enhance seedling stress resistance, thereby improving seedling quality and site restoration success.

Seedling Quality: Product versus Process – Seedling quality is an important component of successful restoration. Typically seedling quality is examined from a product perspective, thus defining functional integrity, operational grading or sometimes performance potential. An alternative approach monitors the process, with product quality the final output.

Planting Stress and Seedling Establishment – Planting stress is prevalent in forest restoration. The act of planting can result in a seedling that does not have proper connections for water movement through the soil-plant-atmosphere continuum (SPAC). Seedling water stress, reduced growth performance and potentially death can occur if this SPAC connection is not restored.  

Seedling Death: Sometimes Simple and Sometimes Complicated – Seedling death can occur in restoration programs as a result of environmental extremes or incorrect management practices. Some problems can be easy to diagnose and correct practices can be implemented to rectify the problem. Other times, issues are complicated and it can be a challenge to define the potential factors causing seedling death.  

Projections of the regional climate model for Southeast Europe generally predict an increasing of temperature and a decrease in precipitation, with some local variations. Higher frequency of extreme weather events and increased flooding can also be expected. This climate change will, among other things, result in changes in habitats and species distribution, and a decrease in biodiversity. In most cases, forest ecosystems will be unable to adapt fast enough to keep pace with changes in climate. Extreme weather events and low precipitation during the growing season will cause high mortality of seedlings after planting. New forests will face the whole range of these changes because of the long lifetime of trees. Reforestation programs must take projections of climate change into consideration. In the long term, new guidelines for site-species matching, provenance selection, and genetic diversity need to be adopted. In the short term, site preparation, planting techniques, and post planting protection need to be improved. In addition, seedling quality (morphological, physiological, and genetic) and planting time need to be specific for each site. New site preparation, planting, and post-planting protection methods are useful tools for short term success measured in seedling survival and initial growth. Seedling quality is essential for short and long term success. Different strategies, such as assisted migration and increased genetic diversity of planting material, can provide better chances for long term success measured in growth, fitness, and capability to produce the next, better adapted generation.

This study compares the relation of initial height and root collar diameter of bareroot hardwoods seedlings to survival and growth in first year after planting. A total of six species used in Serbian reforestation programs were tested (four native: Fagus sylvatica, Ulmus laevis, Fraxinus excelsior, and Acer pseudoplatanus and two exotic: Robinia pseudoacacia, and Quercus rubra), at 6 sites with a wide range of environmental conditions. Initial seedling height and diameter were equally related to field performance and better in forecasting growth than survival. The relation between seedlings initial morphological attributes and survival was species specific, while for all tested species growth was positively correlated to seedling size at planting. Although large seedlings kept their advantage in size, smaller seedlings grew at a higher rate. Both initial H and D should be considered as equally important in operational programs for hardwoods seedling quality testing.

Successful reforestation depends on the quality and health of seedlings. Targeted production in forest nurseries should produce plants that will be able to survive unfavorable environmental and weather conditions in Serbia. Pathogens can reduce the vitality of seedlings and decrease survival after outplanting. The most common pathogens identified on seeds of both conifer and broadleaved seedlings are presented. The most frequently used fungicides for the control of pathogens in Serbian forest nurseries, as well as the best time of their application, are reviewed.