Pedunculate oak (Quercus robur L.) is one of the most important deciduous tree species in the Serbian and European forests. Different negative factors limit natural regeneration of pedunculate oak forests, so producing of high quality seedlings becomes imperative to ensure successful forest restoration. This research was conducted with to aim to determine whether acorn size is related to seedlings quality. Acorns were collected from the natural pedunculate oak forest and divided into two groups by their size. Acorns were sown in the spring into plastic containers after five months cold storage. Size of acorns was in the standard species range, though germination was low (< 20 %). Germination was more then double in group of large acorns in comparison to group of smaller acorns (19.2 %, respectively 8.6 %). Height and root collar diameter of produced seedlings were lower than seedlings produced in seedbeds in commercial nurseries in Serbia, but it was in range of container produced seedlings in some similar researches. Height to root collar diameter ratio and shoot to root ratio were considered as satisfactory for containerized seedlings. There was not strong correlation between acorn size and seedlings quality attributes.

This review covers most of the published literature on potassium (K) fertilization in bareroot seedbeds with the intent to concentrate on the southern United States. The timing and rates of K fertilization for bareroot seedlings are often based on logic and myths and, as a result, K recommendations vary considerably. Some recommend bareroot pine seedlings be fertilized with twice as much K as nitrogen (N) while others apply less than 100 kg ha^-1. It was determined that several long-held claims about K fertilization are invalid. Nursery seedbeds do not need to contain four times as much available K as N and the belief that extra K fertilization will increase freeze tolerance or drought resistance of non-deficient seedlings is invalid. There are no data to support the claim that K fertilization increases root growth or assists in the formation of terminal buds. For sandy seedbeds, there is no need to apply K before sowing. Adding extra K during the fall does not increase seedling morphology or seedling performance when loblolly pine seedlings, at lifting, have more than 0.5% K in needles. A reduction of K fertilization can be achieved by reviewing foliar tests prior to K top-dressings.

The location of the Bolivarian Republic of Venezuela in the tropical region of northern South America, in the Northern Hemisphere, with a total area of 91.64 million ha, of which 49.6 million correspond to natural forests (54.12 % of the national territory). Venezuela shows a series of geographic advantages that allow a rapid growth and development of the trees in comparison with the temperate zones where the growth is extremely slow. However, the occurrence of deforestation processes has intensified in a sustained way in the recent history of the country.

In the period from 1920 to 2008, the loss of 26.43% of the forested area has been recorded. Likewise, in the period 1975-1988, deforestation was estimated at 216,000 ha year^-1, equivalent to 2.9 million ha in 13 years (Catalan 1992). Deforestation has now increased to worrying levels and according to FAO estimates (2010), in Venezuela, a forested area of more than 288.000 ha year^-1 is deforested.

In the middle of the 20^th century several public and private institutions began an important effort to reforest areas of sandy soils of scarce depth on a bed of highly impermeable clay. With erosion processes generated as a result of strong winds that causes severe damage to the little existing vegetation. It was expected that with the passage of time this region could become a desert in the oriental plains of Venezuela. This is how the Maderas del Orinoco Companies (CVG - PROFORCA), the Venezuelan Corporation of Guayana (CVG), Smurfit Kappa Cartón of Venezuela, San Carlos Forestry Development, Masisa. Propulso, among others, started in different regions of the country the establishment of plantations for various purposes. For this they have used fast growing forest species such as: Pinus caribaea var hondurensis, Eucalyptus Urophylla, Acacia magnium, Caraipa llanorum, Tectonia grandis, Hebea brasiliens, Gmelina arborea, Erisma uncinatum, among others. At present, a reforested area of 650.000 ha has been reached. This has favored the protection of natural habitats by reducing the pressure for exploitation and use of the forests.

The legal framework established in the new National Constitution, approved in 1998, is based on decrees of 1825-1829 of the Liberator Simón Bolívar and classifies the territory in diverse forest areas establishing a modern environmental conservation policy. A historical summary and the current legislation with the classification that promises a rational management of the national territory is presented.

Artificial forest regeneration using nursery produced growing stock is commonplace in the Pacific Northwest. High quality seedlings are needed for outplanting success, which depends on a seedling’s ability to establish new roots and overcome stress. Containerized seedling stock is typically grown in artificial growing media. Peat, a popular component of growing media, is a non-renewable resource. Biochar has similar physical attributes to peat, which makes it a potential alternative.  In our study, we grew Douglas-fir seedlings in containers with biochar-amended peat-based growing media to determine if biochar could improve seedling quality. Douglas-fir seeds were sown in March 2016 and seedlings were grown under standard light and temperature conditions at an operational forest nursery for nine months. After nine months, seedling quality was assessed for height, diameter, cold hardiness, and root growth potential. Using biochar did not improve Douglas-fir seedling quality, except for slightly increasing cold hardiness and root growth potential for equivalently sized seedlings. Seedlings grown without biochar had increased height and diameter compared to seedlings with biochar and they had higher root growth potential (all dependent on fertilizer rates). Douglas-fir seedling quality might be improved with biochar amendment if negative growth impacts of soil reaction can be overcome.

Conifer somatic embryogenesis has long been recognized as an advanced vegetative propagation technology. Somatic embryogenesis provides a platform for capturing and long-term preservation of elite genotypes and developing commercial scale-up systems for mass production of plants. Although, significant success has been reported in improving conifer somatic embryogenic protocols, little has been presented to describe the complexity of integrating in vitro (laboratory) and ex-vitro (greenhouse) programs for developing a commercial production system capable of delivering tens of millions of conifer somatic seedlings. This integration requires both programs to run in concert and produce propagules capable of surviving and growing under greenhouse conditions at very early stages. It also requires the integration of seedling development events to ensure the production of quality seedlings that meet needs of the forest restoration program.

This paper describes the importance of protocol optimization for scaling-up the in vitro and ex vitro programs. The ‘biology of scaling’ is discussed in view of plant cell, embryo, germinant and somatic seedling requirements throughout the program. Logistical issues related to protocol optimization and scale-up are addressed. Specific control points for monitoring and controlling the commercial process are presented. The importance of developing standard operating procedures, media batch records, and quality control systems are discussed. Ultimately, a fully integrated system capable of producing tens of millions of conifer somatic seedlings is presented.

The present work demonstrates the effects of moist cold stratification on seed dormancy breaking in Hawthorn (Crataegus monogyna Jacq.). We also examined the fruit and seed morphology. Mature and ripe fruits were collected, the pulp removed and the seeds (stones) left in the sun to dry for three days. Four temperature regimes viz. 4°C, 6.5°C (natural conditions where the fruits were harvested), 10°C and 20°C were used for stimulating seed germination under total darkness. For each treatment, there were four replicates with 50 seeds incubated in a plastic container between two layers of moist sand at 15%. At the end of the experiment, non-germinating seeds were tested for viability using Tetrazolium chloride (TZ).  After 4 months, the final germination (FGP) was expressed as a percentage of the total number of seeds in each treatment. The fruits of Hawthorn were 14.9 ± 0.73 mm long and 15.1 ± 0.84 mm in diameter and weigh 2.05 ± 0.28 g. The seeds were 8.29 ± 0.43 mm long and 6.75 ± 0.39 mm in diameter and weigh (0.25 ± 0.04) g. The thousand-fruit weight was 2,000 g and of the thousand-seeds weight was 280 g. The statistical analysis indicated significant effect (p < 0.0001) of treatment on seed germination. Dormancy in this species was broken most effectively by cold stratification at 4°C and under natural conditions with 76% and 67.5% of FGP, respectively. Most of the nongerminated seeds of C. monogyna were viable (dormant) as judged by TZ.

The paper focuses on the use of alley cropping, an arable agroforestry system comprising rows of trees planted with a companion crop grown in the alleyways between the rows, in two sub-compartments (81B%: 0.75 ha, elevation 715 m asl; 81E: 3.4 ha, elevation 735 m asl) artificially regenerated at 1.80 m x 1.60 m spacing in the south-east of Transylvania (Romania) in 1997 (81B%) and 2003 (81E). The climate (Dfbx, specific to low and middle mountains) and soil (luvisol, of moderate fertility for pure or mixed Quercus petraea stands) are only moderately favourable to strawberry culture. The rows of tree species consists of Quercus rubra, Acer pseudoplatanus, Prunus avium (81B%), and Quercus petraea, Fagus sylvatica, Acer pseudoplatanus, and Larix decidua (81E). Strawberries (variety Elsanta,) were planted at 60 x 60 cm spacing in two pure rows in-between the tree rows as well as within the rows of planted trees. Both plantations were fenced, with manual topsoil hoeing up to four times a year, lighly fertilized (N, P, K complex) and chemically protected against browsing and pests. Strawberry rotation (six years, of which five years - two to six - with fruit production) was longer than the one (maximum three years) recommended in pure crops. Strawberry production reached the maximum level in years 3 or 4.

Under the local conditions, the alley cropping with strawberries had demonstrated to be a viable alternative to the 'classical' monocropping system in terms of (a) survival rate of plants (over 95 per cent), (b) initial height growth of plants (very quick, resulting from reduced competition with grasses and naturally regenerated forest trees such as pioneer species), (c) establishment of a new forest culture, the full forest cover being achieved immediately after the end of strawberry production, as well as (d) economics (early and relevant revenue from the crop).

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).

Despite the importance of forests and trees, Senegal is facing to the loss of forests and the decline of tree diversity and density. This study focuses on Moringa oleifera Lam., Acacia mellifera (Vahl) Benth. and Zizyphus mauritiana Lam. which constitute a significant source of food and economic value for the populations of Casamance. In addition to a germination test, a follow-up of seedlings on different substrates was carried out in the nursery, in order to determine the effect of substrates on some growth parameters (number of leaves, height, diameter and biomass).The substrates used were three potting mixtures of forest soil of Faidherbia albida (FSFA), Elaeis guineensis (FSEG) and Anacardium occidentale (FSAO) and sand with the following proportion: 1/3 sand + 2/3 forest soil). Based on species, the germination rate was higher for A. mellifera (84%) followed by M.oleifera (55%) and Z. mauritiana (50%). The germination rate was more important in FSFA and FSEG than in FSAO. For growth parameters, there was a significant effect (P<0.05) of substrate type on height, diameter, number of leaves and root biomass. In term of growth parameters, the seedling performed better in FSFA and FSEG than in FSAO. The species effect was also significant (P<0.05) with higher root biomass and diameter found in M. oleifera and height and number of leaves in A. mellifera. The most important total biomass was found in FSFA followed by FSEG. Comparing the fraction of biomass according to the part of the seedling, the stem and branch had the higher fraction of biomass for A. mellifera (43%) and M. oleifera (38%) and the leaves for Z. mauritiana (46%).However, thetype of substrate can affect seedling development and growth parameters and the better results were recorded in FSFA and FSEG substrates.

Arbuscular mycorrhizal fungi (AMF) play a significant role for mine tailing rehabilitation due to their sensitivity towards a range of soil pollutants. This beneficial biological agent can enhance plant tolerance to heavy metal contamination. This study screened indigenous AMF associated with growing indigenous ferns and grasses in the mine tailings for potential use in rehabilitating a 3-decade abandoned mined out area in Mogpog, Marinduque. Pterocarpus indicus Willd. (narra) was used as the host plant to establish mycorrhizal fungi association. Among the treatments, indigenous AMF associated with Ferns 1, 2 and 5 generally improved the height and shoot diameter of the narra seedlings and the effect was comparable with commercially available AMF inoculants, MYKOVAM® and MYKORICH®. The dry weight of the roots and nodules was consistently improved by indigenous AMF from Fern2 and Grass1, which had comparable effect with MYKOVAM® and MYKORICH®. Overall, the total seedling dry matter of narra seedlings was significantly stimulated by AMF, irrespective of isolates’ origin. The mycorrhizal root infection by AMF and number of spores in the soil were all high as compared with the uninoculated control counterpart. Lastly, AMF inoculation induced Cu retention in the roots of the seedlings. Thus the results imply that, the mined out indigenous AMF are potential agents to rehabilitate the abandoned mine tailings in the Philippines.