Early growth and survival of tree seedlings is often poor on reclaimed coal surface mines in Appalachia. Biochar produced in bioenergy generation has potential for use as an amendment to improve seedling performance. Mine soil was collected from a recently reclaimed coal surface mine in Wise County, Virginia and mixed with loblolly pine (Pinus taeda L.) sawdust biochar, simulating application rates of 2.3, 11.2 and 22.5 Mg ha^-1. Unplanted leaching columns and 4 L tree planting pots were filled with these biochar-soil mixtures, plus controls of pure mine soil and pure biochar. For the tree planting pots, additional pots were created where the biochar was applied as a topdressing at the same application rates as in the mixtures. One-year-old seedlings of both American sycamore (Platanus occidentalis L.) and black locust (Robinia pseudoacacia L.) were planted. Unplanted leaching columns were leached with collected rainwater for six months to simulate weathering. Trees were grown for one growing season. Black locust had higher average above-ground dry woody biomass (24.4 g) than American sycamore (17.0 g), and also higher below-ground biomass (61.0 g compared to 30.2 g). The pure biochar produced greater average below-ground biomass (99.9 g) than the pure mine soil (46.9 g). All of the biochar treatments produced greater average above-ground woody biomass (19.1 g – 33.4 g) than the pure mine soil (10.9 g). After weathering, biochar provided less available soil phosphorus, calcium and iron than the mine soil itself while increasing soil carbon and organic matter. High (22.5 Mg ha^-1) biochar applications increased soil volumetric water holding capacity to 18.6% compared to 13.4% for pure mine soil. Naturally-occurring herbaceous biomass in the pots was negatively correlated with above-ground woody biomass at r = -0.483. Topdressing and full incorporation of biochar were not significantly different in their effects on biomass. Results suggest that pine biochar either broadcast at 2.3 - 22.5 Mg ha^‑1, or mixed in planting holes with backfill soil, will promote faster above-ground growth and larger root systems in seedlings in mine soils. Further studies should test these methods in the field over multiple years and further refine recommendations of the rate of biochar to use and how best to apply it. New systems are being developed in Appalachia to produce biofuels and biochar from local biomass and to recycle biochar into the land base to enhance future biomass productivity. Applying 4 L of biochar mixed with the backfill of newly-planted trees is the top recommended practice for tree performance.

Variable-radius sampling techniques are commonly used during forest inventories. For each sample tree at a particular sampling point, diameter and height(s) are measured and then weight is estimated using established equations. Heights can require a fair amount of time to measure in the field. Separating the weight per acre estimate into two components; average basal area per acre and WBAR (individual tree weight-basal area ratio) across all points, can often lead to more efficient sampling schemes. Variable-radius sampling allows for a quick estimate of basal area per acre at a point since no individual tree measurements are needed.  If there is a strong relationship between weight and basal area, then by knowing basal area you essentially know weight. Separation into two components is advantageous because in most cases there is more variability among basal area estimates per point then there is in WBAR. Hence, you can spend more resources establishing many points that only estimate basal area – often called “Count” points. “Full” points are those where individual tree measurements are also conducted. There is little published information quantifying the impacts on basal area, weight, etc., estimates among different “Full/Count” sample size ratios at the same site. Inventories were examined to determine this method’s applicability to loblolly pine plantations in southern Arkansas and northern Louisiana. Results show there is more variability among basal area estimates than WBAR and that the amount of trees being “intensively” measured is excessive.  Based on these four plantations, a “Full” point could be installed ranging from every other point to every fifth point depending on site conditions and the desired variable.

When it comes to testing for differences in seedling survival, researchers sometimes make a Type II statistical error (i.e. failure to reject a false null hypothesis) due to the inherent variability associated with survival in tree planting studies. For example, in one trial (with five replications) first-year survival of seedlings planted in October (42%) was not significantly different (alpha = 0.05) from those planted in December (69%). Did planting in a dry October truly have no effect on survival? Authors who make a Type II error might not be aware that as seedling survival decreases (down to an overall average of 50% survival), statistical power declines. As a result, the ability to declare an 8% difference as “significant” is very difficult when survival averages 90% or less. We estimate that about half of regeneration trials (average survival of pines <90%) cannot declare a 12% difference as statistically significant (alpha = 0.05). When researchers realize their tree planting trials have low statistical power, they should consider using more replications. Other ways to increase power include: (1) use a one-tailed test (2) use a potentially more powerful contrast test (instead of an overall treatment F-test) and (3) conduct survival trials under a roof. 

Reforestation in Algeria has been recognized as a priority in different programs for the development and enhancement of forest heritage. Degradation factors of forest and soil contribute significantly to the decline in land values. The Algerian forests in the past, during the colonial period suffered considerable degradation. The degraded forest heritage has been undertaken with serious programs since independence. Several programs for the development of the forest sector through reforestation have been carried out. Unfortunately, the achievements were still below expectations. The launch of the National Reforestation Plan in 2000 has given the forestry sector a new lease of life with a vision that incorporates the productive aspect of reforestation, the industrial aspect, and the recreational aspect. Before the end of the NRP timeline, significant reforestation projects are completed. In a future projection, reforestation is integrated into the land use planning within the framework of the National Plan of Land Use Planning.

Following the Second World War, the number of Cupressaceae plantations in Japan increased, in accordance with government policy for the restoration of timber resources and conservation of soil and water. Currently, these even-aged plantations occupy approximately 44% of the forested area and 24% of the national land area of Japan. Although many of these plantations have become available as timber resources, there are several silviculture-related problems associated with reforestation following clear-cutting of these plantations. The abundant annual precipitation in Japan allows for dominance by competitive vegetation, which makes natural regeneration difficult and increases the cost of silvicultural operations during and after the planting of seedlings. Because the number of seedling producers has decreased, there has been little incentive to keep seedling production techniques up to date. Additionally, damage to planted seedlings by the overabundant sika deer (Cervus nippon) population has increased dramatically in the last dozen years or so. To determine how to overcome these difficulties, various studies are underway in Japan. For example, seedling studies have examined the relationship between seedling size and competitive ability with other species in reforested areas, and have led to the development of lower-cost systems to produce customized Cupressaceae seedlings, as well as measures to minimize transplanting damage to seedlings. Previous studies have shown that no-weeding operations might lower the risk of sika deer browsing seedlings, although this silvicultural countermeasure may potentially reduce seedling growth. Studies have also examined the types of physical protection against sika deer browsing that are most efficient. We must combine these findings into a unified silvicultural system for successful restoration via lower-cost plantations.

Oriental beech established in the Hyrcanian forests, is a valuable tree whose habitats are constantly exposed to destructive factors which change the nutritional status of soil and leaves. Analysis of foliar elements is a commonly used method for studying tree nutrient status that indicates site's quality. Foliar analysis of beech (Fagus orientalis Lipsky) was carried out in Kojour (Mazandaran) in order to assess the nutritional balance of trees in a damaged forest site (a direct result of livestock grazing and anthropogenic perturbations). Sunny leaves of dominant trees were taken in August and foliar concentration of macroelements, N, P, Ca, K and Mg were measured. The diagnosis and recommendation integrated system (DRIS) analysis was applied for evaluating the nutritional state. The results showed deficiency with K and P in disturbed stands. Nutrient Balance Index (NBI) indicated imbalance in nutrient status. These results suggest the usefulness of DRIS for foliar tissue analysis as an indicator of nutritional status and elemental stress in natural forests.

In the past, the entire region of Poland was overgrown by forests. Due to economic changes, the forest cover was reduced to 40% in the 18th century and 21% after the Second World War. After the war, Polish foresters undertook considerable efforts to increase the forest cover to 30.8% by 2015. Polish forests are characterized by the dominance of oligo- and mesotrophic coniferous species (68.7%). This include the pioneer species, Scots pine. It covers approximately 60% of the area. The species composition of Polish forests determined the dominance of artificial regenerations. However, the currently prevailing direction of forest culture is natural regeneration. This tendency is related to “greening” of the forest management, the priority of PERSONAL durability over productivity and culture of multifunctional forests. A natural or seminatural direction of forest culture is being promoted. Renewal of the species such as fir, beech, oak, or spruce from the last stages of succession have always taken place in a natural manner, whereas the statistics are generated by the dominant species preferring open areas during renewal. Currently, the scale of natural regenerations of the pine is increasing. It is increasingly common to value the favorable economic aspect of natural renewal of the species, and the experience of practitioners supported by scientific research increase the likelihood for success. In Poland, the majority of methods of regeneration proceedings (forest cutting) and the law are directed at obtaining and promoting natural renewal. Independent of the concept of natural renewal promotion, the location of Poland in the intermediate climate zone, between the influence of oceanic and continental climates, resulted in the formation of valuable tree stands with high flexibility and tolerance to growth conditions. They are divided into seed stands, excluded stands, and timberlands. Thus, Poland is in possession of a great base for seed collection. At the beginning of 1990s, a rapid need for container seedlings occurred due to numerous disasters (wind-broken trees, gradations). Currently, in Poland, 17 field nurseries are in operation producing 1–10 million seedlings. In 1992, Poland received a loan from the World Bank to conduct afforestations and the “National Program for Increasing the Forest Cover” was started. The main objective of the plan is to increase the forest cover to 30% in 2020 and 33% in 2050. Within the program, it is planned to include vegetation of the natural succession in the area of approximately 80,000 ha. 

Planted forests are an important source of various services (economic, environmental, and social) with increasing portion in the total world’s forest area. Genetic diversity is fundamental for success and sustainability of planted forests. Facing the concern of the reduction of genetic diversity in planted forests, this study offers a review of evidence on comparisons between the levels of genetic diversity in forests established by different regeneration methods. A total of 34 papers comparing genetic diversity in natural forests versus various regeneration methods of 24 tree species examined by the range of markers are reviewed. In most cases, there are no significant differences in genetic diversity between natural and planted forests, followed by an almost equal number of cases with decreased and increased level of genetic diversity. The loss of rare alleles, but also new alleles are reported in planted forests. Although the origin of planting material in the most cases are unknown, the size of parental population is determinant for the level of genetic diversity in the new forest, with the provenancing and seed collection strategy as the most important management practices in planting projects.

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.

Nigeria, a country in West Africa, sits on the Atlantic coast with a land area of approximately 90 million hectares and a population of more than 140 million people. The southern part of the country falls within the tropical rainforest which has now been largely depleted and is in dire need of reforestation. About 10 percent of the land area was constituted into forest reserves for purposes of conservation but this has suffered perturbations over the years to the extent that what remains of the constituted forest reserves currently is less than 4 percent of the country land area. As at today about 382,000 ha have been reforested with indigenous and exotic species representing about 4 percent of the remaining forest estate. Regrettably, funding of the Forestry sector in Nigeria has been critically low, rendering reforestation programme near impossible, especially in the last two decades. To revive the forestry sector government at all levels must re-strategize and involve the local communities as co-managers of the forest estates in order to create mutual dependence and interaction in resource conservation.