The carob tree (Ceratonia siliqua L.) is an important component of the Mediterranean vegetation and its cultivation is important environmentally and economically. It is also an interesting leguminous species for afforestation-reforestation. In this study, carob seeds collected in a representative area of the Mediterranean basin at the national park of Gouraya (Béjaïa, Algeria), were subjected to germination tests under Mediterranean seawater (SW) irrigation of different concentrations (0, 10, 30, 50 and 100% SW) for 15-day period. Before germination tests, a 20 min pre-treatment with 96% sulphuric acid was necessary to overcome seed coat dormancy which does not permit germination. Results showed that the seeds of C. siliqua were able to germinate at different seawater concentration, except for 50% SW and 100% SW which resulted in total inhibition of germination. The maximum number of C. siliqua seed germination of 100% FGP (final germination percentage) appeared at 0% SW and 10% SW. Only 35.5% of the seeds have germinated in 30% SW. Ungerminated seeds of C. siliqua from different SW treatments showed medium germination recovery (FGP_Recov) of 39.9% at 50% SW and low recovery of 18.2% at 100% SW when transferred to distilled water after 15 day-period. Seedlings length and seedling fresh and dry weight were significantly (P < 0.001) decreased with increasing SW concentrations. Seedling water content remained constant in 10% SW in comparison with the control, while it decreased very slightly in 30% SW. These findings may serve as useful information for C. siliqua habitat establishment and afforestation-reforestation programs in coastal sites and for exploiting seawater in the area.

Effects of harvesting residues (needle, bark and branch) on fresh and dry weights of two-year bare root seedlings originated from a seed stand and a seed orchard were examined in Brutian pine (Pinus brutia Ten.) to contribute nursery practices of the species and to estimate utilization possibility of the residues. Averages of seedling fresh and dry weights were 9.24 g and 3.36 g, respectively in polled treatments and origins. Results of analysis of variance showed significant differences (p≤0.05) among the treatments and between seed sources for the fresh and dry weights. Total averages of water content were 61.20% in root, 64.69% in stem and 63.75% in fresh weight of full seedling. Seed orchard seedlings had higher water content in root, stem and full seedling than seed stand seedlings opposite to fresh and dry weights. Averages of water content ranged from 60.39% (control treatment) to 65.94% (bark treatment) in full seedling of polled treatments and seed sources.

How pollen shapes forests and forestry can be illustrated using Siberia’s boreal forests which have historically produced some of the highest pollen concentrations in the Northern Hemisphere. Pollen’s contributions are categorized as follows: 1) forests and timber, 2) nontimber products and services and 3) emerging research at the forest-atmosphere interface. Examples are drawn from Pinus sylvestris (Scots pine), Pinus sibirica (Siberian stone pine) and Pinus koreansis (Korean pine). Pine pollen is not only vital to timber and nontimber products but it serves as a well-studied model system for atmospheric studies.

The tree of heaven Ailanthus altissima (Mill.) Swingle is a multipurpose tree in forestry. However, it is considered an invasive and dangerous plant for native species, and in particular for national parks, where many studies have recorded their involvement in the disturbance of the already developed floral diversity. Assessing the impact of certain abiotic conditions on this species may identify the expected areas to be colonized by its seed propagation. Germination of tree of heaven were tested for germination at constant temperatures of 25, 30, 40°C, and at room temperature varying from 25-30°C coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water) for 6 days of incubation. The kinetic of germination was determined according to five closely related parameters viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), time to 50% germination (T50) and seedling length (SL). For the saline condition, the seeds underwent various NaCl concentrations from 0, 50, 100 or 200 mM. For each treatment, there were four replicates with 50 seeds incubated in a plastic container between two layers of moist sand at 15% of the appropriate treatment and then placed in a culture chamber at 27°C (± 2°C) for 30-day period. The effect of temperature was not significant on the MGT, CVG and T50. However, it was significant (p< 0.0001) on FGP and SL. The maximum germination of 94% was obtained at a temperature of 30°C and the lowest FGP of 40% was obtained at 25°C. For the salinity effect, the FGP of 75% in the control was much higher compared to the seeds treated at 50 mM NaCl with only 17.2% of FGP.  Germination was completely inhibited from 100 mM NaCl. A. altissima can be classified as sensitive to salt stress during seed germination and seedling emergence. The salinity effect then joined the temperature to monitor nature's A. altissima seed propagation.

The leaf area of plant leave scan be considered as an indicator of the plant growth conditions, and its variability is usually associated with adaptation and response to the changing environment. The aim of this study is to investigate the relation of the leaf area parameters on growth of the narrow-leaved ash 1+0 seedlings from the nursery trial and determining variability between the 18 half-sib lines. The seedlings were obtained from seeds collected from 18 maternal trees found in the area of the special nature reserve Upper Danube Region. Ten randomly selected 1+0 seedlings per half-sib line were selected for further study, and all leaves per seedling were collected, herbarized and scanned. The leaf area of each leaf (LACL) was measured using an open-source image processing program – ImageJ, and the total leaf area per seedling (TLA) was calculated. Also, the number of leaves per plant (NCL) as well as the number of leaflets within each imparipinnate compound leaf (NLCL) were counted. The results showed that differences between studied attributes were statistically significant among 18 selected half-sib lines (p < 0.05). The most variable parameter was the total leaf area per seedling (TLA; CV=68.98%), which is strongly correlated to the leaf area per each leaf (LACL; r=0.95) and the number of leaflets (NLCL; r=0.94). In this study, we confirmed that leaf parameters were highly correlated to the growth of one-year-old Fraxinus angustifolia seedlings.

In this study we investigated the dynamics of growth and quality features of 1+0 Austrian Pine (AP; Pinus nigra Arn.), Scots Pine (SP; Pinus sylvestris L.) and Maritime Pine (MP; Pinus pinaster Aiton) seedlings in containers Yukosad (YS; hard plastic, 75cm³, 610 seedlings m^-2) and Siset (SS; gray cardboard with white coating, 128 cm³, 589 seedlings m^-2). The experiment, for all Pine species, was conducted in randomized blocks in four replications. Each replication contained 10 multipots of each container type. After the seed germination, every 15 days, i.e. 10 times during the vegetation season, 10 seedlings of each of 4 replications, i.e. 40 seedlings of each container and Pine species, were analyzed. The following morphological characteristics were measured: shoot height (SH), root collar diameter (RCD), shoot dry weight (SDW), number, length and dry weight (RDW) of I, II and III order lateral roots (FOLR, SOLR and TOLR) and of the central root. Quality ratios and indexes were calculated. The dynamics of growth of selected features during the vegetation season was expressed as trend lines. AP and SP seedlings, grown in containers YS had higher values of almost all measured traits (SH, RCD, SDW, number, length and dry weight of FOLR, SOLR and TOLR). However, in AP, the SS seedlings had better values of quality indexes and ratios (SQ, DQI, SDW/RDW and RDW/SDW ratio), than YS seedlings. SP seedlings, except for SQ, had better quality indexes in YS container. MP seedlings, with some exceptions, have better above ground quality features in SS containers, while root systems don’t differ significantly in both containers. Root quality indicators (root intensity and root bound indexes) are more favorable in SS containers in all Pine species. The polynomial trend lines in AP and SP grow in similar way and intensity in both containers, gradually increasing during the vegetation season. MP seedlings differ in much more intensive growth of above ground features, especially in the half of the vegetative period in both containers, while during this period root quantity and length stagnates. Generally, the quality of AP and SP seedlings is more or less equal and satisfactory in both containers, while MP seedlings show slightly better results in SS container.

This review provides information and opinions about irrigation practices in pine nurseries. Even when nurseries receive more than 15 mm of rainfall week^-1, managers irrigate seedbeds to increase germination, increase seed efficiency, and increase root growth. In the southern United States, a 7-month old pine seedling in an outdoor nursery typically receives 2 to 6 kg of water supplied from either sprinklers (39 nurseries) or center-pivot irrigation (12 nurseries). Most nursery managers do not intentionally subject the crop to moisture stress, since most reforestation sites receive adequate rainfall, and many studies show that reducing root mass does not increase seedling performance. In fact, nursery profits can be reduced by more than $13,000 ha^-1 when deficit irrigation reduces average seedling diameter by 1 mm. Although some researchers believe that failure to properly drought stress pine seedlings might increase outplanting mortality by up to 75%, research over the past 40 years does not support that myth. When pine seedlings average 5 mm (at the root-collar), water stress is not a reliable method of increasing tolerance to an October freeze event. In several greenhouse trials, researchers grew and tested seedlings that nursery managers would classify as culls (i.e., dry root mass < 0.5 g). Unfortunately, it is common for researchers to make irrigation recommendations without first developing a water-production function curve.

Austrian pine (Pinus nigra Arnold) seedlings are frequently used for afforestation/reforestation and restoration practice in Serbia. Indeed, the seedlings of various stock types are produced by almost all forest nurseries in Serbia and bareroot seedlings are mostly common. The aim of this study is to analyze the method of sowing and sowing density on some morphological characteristics and quality of one-year-old Austrian pine seedlings. Sowing in rows and random sowing across all seedbed space were performed. In both cases, the sowing density (R1 - 8 g m^-1, R2 - 40 g m^-2) and half of the recommended sowing density (S1 - 4 g m^-1, S2 - 20 g m^-2) were applied. Seedlings from both treatments had average height and root collar diameter values in the range of 4.91 to 5.73 cm, and 1.25 to 2.34 mm, respectively. Observed characteristics of seedlings (height - H, root collar diameter - RCD, root length - RL, dry weight of shoot - SDW, root - RDW and seedlings - SLDW, sturdiness coefficient - SQ and quality index - QI) were conditioned by treatment (One-Way ANOVA, p<0.05). Shoot to root ration was similar at seedlings of all treatments and ranged from 1.33 to 1.63. In both cases, decreased density produced better results. The combination of lower sowing density (20 g m^-2) and sowing in all seedbed areas (S2) provided the best seedlings with QI - 0.21.

The main objective for even-aged plantation (EAP) management of producing sawlog material has driven practices towards low initial planting densities and lower post thinning densities. For semi-shade tolerant species, the resulting stand density potentially leaves enough growing space for the introduction of a second cohort of trees in the understory, making it a two-aged plantation (TAP). TAPs could have many silvicultural benefits, especially in sensitive areas where intensive treatments associated with EAPs are incompatible with local management objectives. White spruce (Picea glauca) is a good candidate species for modeling TAPs because it is the most widely planted tree species in Canada and has proven tolerance to understory planting. SORTIE-ND, a single-tree spatially explicit growth model was used to explore the yield of variable density and rotation length scenarios when each white spruce cohort is introduced mid rotation, compared to traditional even-aged management. All TAP scenarios tested produced more sawlog volume and more merchantable volume than equivalent densities of EAPs. The lowest density tested, 400 stems ha^-1 planted every 35 years, had the highest sawlog yields (3.23 m3 ha^-1 yr^-1). Considering smaller size products changes the optimum TAP scenario but maintains the advantage over EAPs.

The genus Callistemon belongs to the family Myrtaceae and comprises 34 species. They are woody aromatic trees or shrubs that are widely distributed in the wet tropics. According to the scientific literature, research on seed germination of this genus was rarely carried out. The germination requirements of Callistemon citrinus and Callistemon linearis were studied under controlled conditions in the laboratory. Seeds of both species were tested for germination at constant temperatures of 25°C, 30°C, 40°C, and at room temperature (23 ± 2°C) coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water) for 25 days of incubation. The kinetics of germination was determined according to four closely related parameters viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG) and time to 50% germination (T50). The room temperature of 23 ± 2 °C was found optimally suitable for both species, with 80% FGP and 11.1 days MGT for C. citrinus, and only 21.7% FGP and 12.4 days MGT were recorded for C. linearis. Furthermore, significant decrease in FGP was observed in both species at 25°C, 30°C and 40°C of temperature. The analysis also revealed that day 12-15 after seed sowing is suitable for final counts. Due of its very low FGP, seeds of C. linearis need an additional study to determine their viability.