Root Collar Diameter Growth Research Articles

Survival and Growth Performance of Calophyllum inophyllum L. Seedlings in Peat Soil and at Different Levels of Groundwater

Selecting proper tree species for revegetation is important for restoring tropical peatland. Tamanu (Calophyllum inophyllum L.) has been suggested one of the promising native species in Indonesia for the revegetation of tropical peatland; however, there is a lack of understanding of its growth in peat soil with different groundwater levels. We investigated the survival rate, plant height, number of leaves, root collar diameter, and dry biomass of tamanu seedlings grown in peat soil with different groundwater levels using a randomized block design in a water tank. The study involved five groundwater level treatments and 12 tree-level replicates each: M0 (non-groundwater level, control); M1 (−15 cm below the soil surface); M2 (−10 cm); M3 (−5 cm); and M4 (0 cm, soil surface level). The results showed that all tamanu seedlings survived in every treatment. However, their plant height, number of leaves, and root collar diameter growth were significantly inhibited in the highest groundwater level condition (M4, 0 cm) at 81 days after sowing, while their growth in −15 cm of groundwater level (M1) was as good as the growth in the fully drained conditions in M0 (control). This result indicates that the groundwater level should not be higher than −15 cm for the growth of tamanu. Considering that peatlands in Indonesia are assessed to be degraded when the groundwater level is lower than −40 cm, this study suggests that maintaining groundwater levels between −40 cm and −15 cm in peatland is the best condition for rapid growth of early tamanu seedlings while protecting peatlands. Further studies are needed to extend the range of water levels and water treatment duration.

Interactive Effect of Fertilization and Biochar on the Growth of Juniperus scopulorum under Various Shading and Irrigation Conditions

The global demand for landscape trees has been amplified with the increasing anthropogenic activity. South Korea has also witnessed a surge in demand for landscape plants, among others, Juniperus scopulorum gaining popularity for its ecological, economic, adaptability, and management attributes. However, the optimum management practice for high-quality Juniperus seedling production in South Korea remains unknown. This research was conducted on the one-to-two-years-old two cultivars of J. scopulorum, namely Blue Angel and Blue Heaven seedlings, to investigate the combined impacts of varying fertilizer concentrations (0 ppm, 150 ppm, 300 ppm) and biochar content (0% and 20%) under contrasting shading intensities (0%, 35%, 55%) and irrigation levels (200 ml, 400 ml, 800 ml). The study revealed that biochar and fertilizer amendment significantly (p < 0.01 and p < 0.05) enhanced the height and root collar diameter growth in Blue Angel and Blue Heaven in light shade intensity (0–35%) and higher irrigation (400–800 ml) conditions. Similarly, seedlings planted in 20% biochar and 300 ppm fertilizer yielded higher foliar, stem, and root biomass in low shade and higher irrigation conditions. The amount of shade and irrigation and their interactions significantly affected the morphological growth of seedlings for both cultivars, causing positive interaction with soil amendment (biochar and fertilizer application). These findings suggest that efficient seedling production of J. scopulorum management should focus primarily on light shading and moderate irrigation under biochar and higher fertilizer application. The research contributes valuable insights toward optimizing management practices and reducing costs associated with J. scopulorum seedling production in the region. Keywords: biochar, fertilizer, irrigation, Juniperus scopulorum, shading

Effect of arbuscular mycorrhizal symbiosis on growth and biochemical characteristics of Chinese fir (Cunninghamia lanceolata) seedlings under low phosphorus environment.

The continuous establishment of Chinese fir (Cunninghamia lanceolata) plantations across multiple generations has led to the limited impact of soil phosphorus (P) on tree growth. This challenge poses a significant obstacle in maintaining the sustainable management of Chinese fir. To investigate the effects of Arbuscular mycorrhizal fungi (AMF) on the growth and physiological characteristics of Chinese fir under different P supply treatments. We conducted an indoor pot simulation experiment in the greenhouse of the Forestry College of Fujian Agriculture and Forestry University with one-and-half-year-old seedlings of Chinese fir from March 2019 to June 2019, with the two P level treatment groups included a normal P supply treatment (1.0 mmolL-1 KH2PO4, P1) and a no P supply treatment (0 mmolL-1 KH2PO4, P0). P0 and P1 were inoculated with Funneliformis mosseae (F.m) or Rhizophagus intraradices (R.i) or not inoculated with AMF treatment. The AMF colonization rate in the root system, seedling height (SH), root collar diameter (RCD) growth, chlorophyll (Chl) photosynthetic characteristics, enzyme activities, and endogenous hormone contents of Chinese fir were estimated. The results showed that the colonization rate of F.m in the roots of Chinese fir seedlings was the highest at P0, up to 85.14%, which was 1.66 times that of P1. Under P0 and P1 treatment, root inoculation with either F.m or R.i promoted SH growth, the SH of R.i treatment was 1.38 times and 1.05 times that of F.m treatment, respectively. In the P1 treatment, root inoculation with either F.m or R.i inhibited RCD growth. R.i inhibited RCD growth more aggressively than F.m. In the P0 treatment, root inoculation with F.m and R.i reduced the inhibitory effect of phosphorus deficiency on RCD. At this time, there was no significant difference in RCD between F.m, R.i and CK treatments (p < 0.05). AMF inoculation increased Fm, Fv, Fv/Fm, and Fv/Fo during the chlorophyll fluorescence response in the tested Chinese fir seedlings. Under the two phosphorus supply levels, the trend of Fv and Fm of Chinese fir seedlings in different treatment groups was F.m > R.i > CK. Under P0 treatment, The values of Fv were 235.86, 221.86 and 147.71, respectively. The values of Fm were 287.57, 275.71 and 201.57, respectively. It increased the antioxidant enzyme activity and reduced the leaf's malondialdehyde (MDA) content to a certain extent. It is concluded that AMF can enhance the photosynthetic capacity of the host, regulate the distribution of endogenous hormones in plants, and promote plant growth by increasing the activity of antioxidant enzymes. When the P supply is insufficient, AMF is more helpful to plants, and R.i is more effective than F.m in alleviating P starvation stress in Chinese fir.

Selection of Soil and Water Conservation Technologies and Native Tree Species for Rehabilitation of Degraded Arid Lands in Southeast Ethiopia

The large-scale commercial agriculture, mining, expansion of sedentary agricultural settlements, and overgrazing in Ethiopian pastoral areas have become a major cause of land degradation. Such activities reduce grazing capacities and impoverish already fragile living conditions of the pastoralists. Such an increase in land degradations necessitates urgent calls for interventions. The main objectives of this study were to select the best performing soil and water conservation technologies and native tree species to restore degraded lands of arid and semiarid conditions in Liben District of Guji Zone, Oromia Reginal State, Ethiopia. Four locally grown and locally preferred tree species, namely, Cordia africana, Acacia tortilis, Acacia goetzei, and Combretum molle, were planted in five soil and moisture conservation structures (control, half-moon, spot hoeing, mowing, and trench). The survival rate and height and root collar diameter (RCD) growth of planted tree species were collected two years after planting. A significantly higher survival rate, RCD, and height growth of planted seedlings were recorded from half-moon (52.44 ± 12.48%; 1.66 ± 0.31 cm; 51.57 ± 2.79 cm) and trench (64.00 ± 11.49%; 1.92 ± 0.27; 69.67 ± 2.62 cm) moisture conservation structures, respectively. Acacia tortilis (58.22 ± 12.38%) and Acacia goetzei (42.99 ± 8.81%) had better survival rate than Cordia africana (4.00 ± 1.91%) and Combretum molle (24.22 ± 7.34). Cordia africana attained the largest RCD (2.50 ± 0.34 cm) and height (95.83 ± 17.25 cm) growth, followed by Acacia tortilis and Acacia goetzei. It is concluded that Acacia tortilis and Acacia goetzei are better species to grow in degraded lands. The half-moon and trench moisture conservation structures have a great potential for degraded areas of the arid and semiarid conditions of Ethiopia for better tree establishment, survival, and enhanced growth thereby rehabilitation of degraded lands.

The Root Collar Diameter Growth Reveals a Strong Relationship with the Height Growth of Juvenile Scots Pine Trees from Seeds Differentiated by Spectrometric Feature

This study is intended for forest owners considering options to increase the efficiency of the production of forest seedlings in automated nurseries. In the short rotation technology of the Scots pine (Pinus sylvestris L.), the production of seedlings was integrated in the process of grading seeds by spectrometric features, followed by the fall outplanting of containerized seedlings to a restorable post-pyrogenic site. There are studies of the spectrometric effect grading viable seeds, but a negligible amount of testing has been conducted on the seedling’s field performance from these seeds. It was very important for us to evaluate the morphogenesis of juvenile Scots pine trees in relation to the change in morphological features—increase in root collar diameter (RCD-increment) and increase in stem height (SH-increment)—in the second and third growing season from the field outplanting. To determine the nature of the interaction between independent (RCD increase), dependent (SH-increment), and categorical (seed spectrometric categories and timespans) variables, a regression analysis was performed using the R statistical software. All coefficients of the linear models are statistically significant at the 1% significance level, and all are positively associated with an increase in seedling height. On average, a RCD increment by 0.1 cm causes a SH-increment by 0.72 ± 0.16 cm (p = 9.779 × 10−6). In addition, in 2020, compared to 2019, the SH-increment was 5.46 ± 0.37 cm (p &lt; 0.001). The seeds’ differentiation into spectrometric categories is strongly correlated with the stem height increment (p &lt; 0.001). Thus, in order to improve the plant propagation protocol, it seems advisable to first condition the seeds in accordance with the spectrometric feature, and to then apply a coating (by pelleting or encapsulating) in order to improve the storage and seeding conditions. For a medium-term assessment of the short rotation technology with an integrated seed spectrometric grading in the future, the morphogenesis of Scots pine trees at 5, 7 and 10 growing seasons from the seedlings field outplanting is controlled.

Effect of Seed Pretreatment Methods on Germination and Early Seedling Growth of Senna spectabilis

The objectives of the study were to evaluate the effect of pretreatment methods on germination of Senna spectabilis seed and determine the effect of pretreatment methods on height and root collar diameter growth of Senna spectabilis seedlings. The experimental treatments involved were control; seeds soaked in cold water for 12 h, 24 h, and 48 h; seeds soaked in hot water and allowed to cool for 12 h, 24 h, and 48 h; and nicked seeds using secateurs. The experiment was arranged in a completely randomized design (CRD) with four replications. The data variables assessed were seedling height, root collar diameter, and survival rate. Data were subjected to one-way ANOVA using Minitab software. Results showed that there were significant differences p ≤ 0. 05 among treatment means on germination, seedling height, and root collar diameter, while the survival rate was not statistically significant p ≥ 0.05 . Nicked seeds and those soaked in hot water and allowed to cool for 12 h had an outstanding performance in terms of germination and seedling growth. It is, therefore, recommended that farmers should be encouraged to use nicked and hot water soaked for 12 h seed in order to achieve high germination and growth efficiencies in their homestead gardens.

Root growth potential and seedling growth of kamagong (Diospyros blancoi A. DC.) influenced by root pruning

Abstract Quality seedlings are vital to the success of any reforestation project. This can be attained and improved by employing nursery management practices like root pruning. This study was carried out to determine the effect of root pruning on root growth potential and growth of kamagong seedlings. Three-month-old seedlings were obtained from the Learning Laboratory for Forestry and Agroforestry, College of Forestry and Natural Resources, University of the Philippines – Los Baños, where treatments non-root pruned and root pruned were applied to seedlings repotted in larger polybags. After 80 days, root pruning did not significantly affect height and root collar diameter growth. Shoot dry mass, root collar diameter, root length, total tree dry mass, sturdiness quotient, seedling mortality were consistent in between treatments. Non-root pruned seedlings yielded significantly higher root volume and root dry mass while root pruned seedlings have significantly higher shoot height, root: shoot ratio, and seedling quality index. Attainment of moderate Root Growth Potential (RGP) based on root length and root volume was influenced by root pruning. Expressions of RGP were positively and significantly correlated to root dry mass, sturdiness quotient and seedling quality index. In conclusion, root pruning of this critically endangered species increases its quality as planting stock.

Growth of Deciduous and Evergreen Species in Two Contrasting Temperate Forest Stands in Korea: An Intersite Experiment.

Poor seedling establishment and growth can be a result of the limitation of light and soil resources in the forest understory. Here, we investigate the interacting effects of stand and soil characteristics on the seedling growth of deciduous species (Fraxinus rhynchophylla and Zelkova serrata) and evergreen species (Pinus koraiensis) through a 3-year intersite experiment in two contrasting forest stands. Seedlings were grown in both oak and pine stands using two different soil types, i.e., gray-brown forest soil (GB) and red-yellow forest soil (RY). Soil physicochemical properties, light intensity, tree-seedling height, root-collar diameter (RCD), and biomass growth were analyzed between two stands and/or soil types. Light availability was generally more abundant in the pine stand (mean: 1074.08 lx or 20.25%) than the oak stand (mean: 424.33 lx or 9.20%) throughout the year. The height and RCD growth of fast-growing and deciduous F. rhynchophylla and Z. serrata were higher in the pine than in the oak stand, particularly in GB soil. The growth of the slow-growing and evergreen P. koraiensis was not affected by the forest stand, except for its higher root growth in the oak stand and RY soil. Therefore, abundant light availability can enhance the growth and seedling establishment of F. rhynchophylla and Z. serrata in the pine-stand understory. Contrarily, P. koraiensis may be planted in the understory regardless of light condition, but with a slower growth rate.

Growth Rate and Leaf Functional Traits of Four Broad-Leaved Species Underplanted in Chinese Fir Plantations with Different Tree Density Levels

The close-to-Nature management method of interplanting broad-leaved trees after thinning of monoculture plantations is an important mixed species restoration model to improve the ecological service and functions effectively as well as to reduce the productivity decline of the multi-generation continuous planting of monoculture. Thus, the selection of tree species for establishing mixed forest and its ecological adaptability are the key issues. In this study, we conducted thinning experiment in an 11-year-old Chinese fir plantation with retention density of 900 trees/ha, 1200 trees/ha and 1875 trees/ha, and then underplanted four broad-leaved species, Schima superba, Phoebe bournei, Tsoongiodendron odorum and Michelia macclurei. After three years, we analyzed the growth rate and leaf functional traits of the broad-leaved species and their correlations with stand characteristics. The results showed that growth rate of seedlings of the four broad-leaved species were significantly different (p &lt; 0.05) among different tree density levels and species. Low tree density favored seedling growth compared with high tree density and seedlings of T. odorum and S. superba performed best. However, leaf functional traits varied significantly (p &lt; 0.01) among species only, and T. odorum had the largest specific leaf area, the smallest leaf mass per unit area, the smallest leaf tissue density, relatively large leaf thickness, and relatively small dry matter content. The leaf C content varied significantly among tree density levels and species; leaf N content varied significantly among species only; and leaf p content varied among tree density levels only. Correlation analyses between growth characters and leaf functional traits showed that height growth was significantly correlated with leaf N content (r = 0.686; p = 0.041) and with C:N ratio (r = −0.682; p = 0.043). Root collar diameter growth was significantly correlated with specific leaf area (r = 0.820; p = 0.007), leaf N content (r = 0.685; p = 0.042), leaf thickness (r = −0.706; p = 0.034) and leaf mass per unit area (r = −0.812; p = 0.008). Thus, leaf functional traits possibly predict diameter growth better than height growth. As a whole, growth rate and leaf functional traits could be used as a guide for selection of species for under planting in thinned pure monoculture plantations to establish conifer-broadleaved mixed forests. Based on growth rate and leaf functional traits, T. odorum appeared to be suitable for planting under low tree density stands where the degree of shading is low.

Mixture Compound Fertilizer and Super Absorbent Polymer Application Significantly Promoted Growth and Increased Nutrient Levels in Pinus massoniana Seedlings and Soil in Seriously Eroded Degradation Region of Southern China.

Pinus massoniana is the pioneer tree species in the red soil regions of southern China, however, the serious understory soil erosion and nutrient deficiency in that region are the main factors restricting the growth of P. massoniana. This field study examined the effects of compound fertilizer and super absorbent polymer (SAP) on the physiology, growth characteristics, biomass, soil nutrient, plant nutrient content, and nutrient uptake efficiency of 1-year-old P. massoniana seedlings for 2 years at Changting, Fujian in South China. One control (no fertilizer, CK) and fertilization treatments were established, namely, single compound fertilizer application (0.94, 1.89, and 3.56 g⋅plant–1) and mixture compound fertilizer and SAP application (0.94 + 1.01, 1.89 + 1.01, and 3.56 + 1.01 g⋅plant–1). Fertilization significantly improved the physiological performance, root collar diameter growth, height growth, biomass, and nutrient uptake of the seedlings. Compared with other fertilization treatments, the mixture compound fertilizer and SAP application significantly improved the seedling photosynthesis, which meant that the SAP had a significant effect on promoting photosynthesis. Under the mixture compound fertilizer and SAP application, the whole biomass of the seedlings was higher than that of all other treatments. Fertilization significantly increased the nitrogen (N), phosphorus (P), and potassium (K) content in the soils, leaves, stems, and roots of the seedlings, respectively. The P content was the main factor affecting growth characteristics and contributed to 58.03% of the total variation in seedling growth characteristics (P < 0.01). The N:P ratio of CK in the soils, leaves, and stems were higher than that of all the fertilization treatments, indicating that the severely eroded and degraded region had little P and required much of P. The principal component analysis indicated that the F2S (1.89 + 1.01 g) was the optimum fertilization amount and method in this experiment. These results provide a theoretical basis for the fertilization management of P. massoniana forests with severely eroded and degraded red soil regions.

Longleaf pine seedling growth and survival: Effects of season and intensity of simulated prescribed burning

Restoration of longleaf pine (Pinus palustris Mill.) forests is an important land management goal in the southern United States. To achieve this goal, longleaf pine is increasingly being planted across its range. Fire is an important ecological factor that has historically shaped and sustained longleaf pine forests. However, we have limited information on how fire impacts longleaf pine seedlings in newly established plantations. We conducted this study in Northwest Florida to examine the effects of fire intensity (low intensity ((LI), ∼100 °C), medium intensity ((MI), ∼300 °C), high intensity ((HI), ∼500 °C), and an untreated control) on survival, growth (root collar diameter (RCD) and height), physiological processes (net assimilation (A), stomatal conductance (gsw), and intrinsic water use efficiency (iWUE)), and biomass allocation of longleaf pine seedlings over a period of six months after fire was applied in four seasons (summer, fall, winter, spring). Within a given season, the survival of seedlings did not significantly differ at different fire intensities, except in the summer (α = 0.05). For the summer application, survival was lower (18%) in the HI treatment compared to the MI (98%), LI (93%), and control (93%) (p = 0.003). RCD growth was significantly affected by fire intensity treatment only for the summer application. For the summer application, RCD growth six months after treatment (MAT) was highest (7.3 mm) in the control compared to the LI (2.7 mm), MI (2.7 mm), and HI (2.0 mm) (p = 0.021). The height growth of seedlings did not significantly differ at different fire intensities, though their values were greater at 6 months compared to 3 months. The effect of fire temperature on percent biomass allocation was only significant for the fall foliage (p = 0.004). Neither root, stem, nor total shoot percent biomass significantly differed for any other season. Largely, A, gsw, and iWUE were not significantly affected by fire temperature. iWUE did differ for MAT (p = 0.003), however, no pattern could be discerned. Overall, our observations suggest that longleaf pine seedlings are highly resistant and resilient to fire intensity in different seasons, with some vulnerability to high-intensity summer fires which can adversely affect their survival and growth. Summer burning is still a viable option for seedling survival provided conditions on the ground favor low/medium intensity fire.

Use of direct seeding and seedling planting to restore Korean pine (Pinus koraiensis Sieb. Et Zucc.) in secondary forests of Northeast China

The poor natural regeneration of Korean pine represents a substantial hurdle limiting the restoration of secondary forests to mixed broad-leaved Korean pine forests (MBKPFs). Active restoration based on direct seeding or planting seedlings is accordingly considered to be a prerequisite for promoting Korean pine recruitment in secondary forests. To evaluate the most effective practices for restoring Korean pine in secondary forests, we studied the effects of microsites associated with gaps of different sizes and within-gap locations on direct seeding (rodent access/exclusion and soil/litter cover) and seedling planting (1-, 2-, and 3-year-old seedlings). We found that an average of 82.4% of sown seeds were eaten by rodents, with only 9.9% germinating and surviving after two growing seasons. Among the germinated seedlings, 37.6% were subsequently excised by rodents, whereas 6% died due to other natural causes. Furthermore, compared with the control sites (forest understorey), we detected no significant differences among the different microsites with respect to an effective reduction in rodent damage or promotion of seed germination, whereas rodent exclusion was more effective in protecting seeds from predation than the effect of microsite. With regards to planted seedlings, we found that the proportion of survival and relative root collar diameter growth were highest in the center (64.1%) and edge (60.0%) sites of large gaps, and that the survival of planted seedlings (43.7%) was considerably higher than that of seedlings derived from directly sown seeds (9.9%). Collectively, our findings indicate that, owing to seed predation and seedling excision by rodents, direct seeding with either mesh or soil cover would not represent an effective strategy for promoting Korean pine recruitment in secondary forests. Accordingly, for the purposes of restoring secondary forests to MBKPFs, we recommend planting 3-year-old Korean pine seedlings in large gaps within secondary forests.

The Use of Deep Container and Heterogeneous Substrate as Potentially Effective Nursery Practice to Produce Good Quality Nodal Seedlings of Populus sibirica Tausch

Nursery practices are considered major factors influencing seedling quality, which are likely to be maintained in the early establishment phase in the field. Here, we investigated the effects of container depth and substrate heterogeneity on the growth of Populus sibirica nodal seedlings to suggest an effective nursery practice for producing quality seedlings appropriate for forest establishment in a dry environment. We used two substrate heterogeneities (homogeneous and heterogeneous) and two container depth treatments (30 and 60 cm). Variations in root collar diameter (RCD) growth, height growth, stem and root biomass, root to stem ratio, and root mass in the first 15 cm depth from the soil surface across the treatments were computed. Results revealed that both substrate heterogeneity and container depth had no significant effects on the RCD and height growth of P. sibirica seedlings but significantly improved their root and stem biomass. Seedlings in the 60 cm containers generally accumulated higher root biomass than those in the 30 cm containers. There was an interaction effect of container depth and substrate heterogeneity treatments on root and total dry mass, such that seedlings grown in the 60 cm container using heterogeneous substrate resulted in the highest root and total biomass. Analyses of proportional root growth in the upper 15 cm of the containers compared to the total indicated that both the main effects of deeper containers (60 cm) and heterogeneous substrate have fewer roots at this depth, indicating a greater root density in the bottom of the deeper containers. Therefore, deeper containers and heterogeneous substrate may be used as an effective nursery practice to produce seedlings with root traits potentially suitable for harsh conditions, such as arid and semi-arid environments. However, further studies using other seedling morphological traits in conjunction with field-trial tests are needed for a definitive assessment of the effectiveness of deeper containers and heterogeneous substrate in producing good quality seedlings potentially suitable in a dry environment.

White mulch and irrigation increase black truffle soil mycelium when competing with summer truffle in young truffle orchards

The black truffle (Tuber melanosporum Vittad.) and the summer truffle (Tuber aestivum Vittad.) are two of the most appreciated edible fungi worldwide. The natural distributions of both species partially overlap. However, the interspecific interactions between these truffles and how irrigation and mulching techniques impact the dynamics between them are still unknown. Here, an experimental truffle plantation with Quercus ilex was established in Maials (Catalonia, Spain), combining three soil mulch treatments (white mulch, black mulch and bare soil as a control) and two irrigation regimes (irrigated and non-irrigated as a control) to investigate truffle mycelial dynamics in soil when both truffle species co-occur. The development of truffle mycelium in two different seasons (spring and autumn) in two consecutive years (2017 and 2018) was quantified using qPCR. Truffle mycelia of both species showed greatest development under white mulch. When mycelia of both truffle species co-occurred in soil, irrigation combined with white mulch resulted in greater quantities of T. melanosporum mycelial biomass, whereas the control irrigation treatment favoured the development of T. aestivum. Mulch treatments were also advantageous for seedling growth, which was expressed as root collar diameter and its increment during the study period. Significant relationships between root collar diameter and root growth and the amount of mycelial biomass in the soil were observed for both truffle species. Our results indicate the potential advantages of using white mulch to support irrigation in truffle plantations located in areas with dry Mediterranean climatic conditions to promote the development of Tuber mycelium.

Effects of Pot Size and Planting Media on the Early Seedling Growth Performance of &amp;lt;i&amp;gt;Azadirachta indica&amp;lt;/i&amp;gt; &amp;lt;i&amp;gt;A. Juss&amp;lt;/i&amp;gt;

Neem is a multipurpose tree that is provides food and insecticide and is used for its great number of ethnomedicinal properties. Neem, known botanically as Azadirachta indica A. Juss is a member of the mahogany family (Meliaceae), and orders Geraniales, and is synonymous with Melia azadirachta Linn and Melia indica Brandis. Azandirachta indica originates from the arid and semi-arid areas of Burma and Northeast India. Neem is a large evergreen tree 12 to 20 meters tall and may reach a girth of 1.8 to 2.5 meters with a round, dense crown. The aim of this study was to determine appropriate pot size and growing medium for Azadirachta indica A. Juss seedlings, which will be used for successful plantation. For this purpose, polyethylene pots of 15 cm length and 8, 10 and 12 cm lay flats diameter were used. As growing medium, 5 different treatments were used, containing different ratios of top/local soil (TS), forest soil (FS), compost (Co) and sand soil (SS) collected from local, natural forest environments and highly decomposed compost (the different materials get from locally easily available). The experimental design was a Randomized Complete Block Design with 3 replications under open field conditions of forestry nursery. Some morphological properties of the seedlings, such as seedling height and root collar diameter growth parameters were measured ever two weeks for four (4) months old seedlings. The finding of this experimental study revealed/showed that relatively higher growth recorded in GM2 and GM4 ratio of composite growing media (3/2 topsoil:2 compost:1 sand soil) composites soil mixed growing media with both 10 cm and 12 cm lay flat polythene pots (PS2 and PS3) should be utilized for raising Azandirachta indica (Neem) seedling to achieve the best seedlings quality. To obtain the best or optimum seedling quality were the interaction effects of growing media and appropriated containers (pot sizes) were important and basic than doing experiment separately. Knowing the best growing media was the major determinant to get the best quality seedlings at the nursery for successful plantation.

Effect of substrate formulations on seedlings of Araucaria angustifolia (Bertol.) Kuntz, a critically endangered species from Southern Brazil

Araucaria angustifolia, vulgarmente conhecida como araucária ou pinheiro do Paraná, é uma espécie de planta ameaçada de extinção, nativa do sul do Brasil. O cultivo desta espécie é uma abordagem importante para reduzir o desmatamento assegurando a geração de renda. O presente estudo teve como objetivo avaliar os efeitos de diferentes formulações de substrato no crescimento, qualidade e teores de clorofila de mudas de araucária em um sistema conjugado substrato/recipiente, como uma abordagem para promover a propagação e o cultivo da espécie. As sementes foram semeadas em quatro composições diferentes de substrato: F73 (casca de pínus, fibra de casca de coco, fertilizante de liberação lenta [FLL] e fertilizantes fosfatados), F55 (casca de pínus, fibra de casca de coco [em maior proporção que em F73], FLL e fertilizantes fosfatados), T55 (casca de pínus, turfa nacional, FLL e fertilizantes fosfatados) e CC55 (casca de pínus, turfa de esfagno, palha de arroz, FLL e fertilizantes fosfatados). As mudas foram mantidas em uma área de viveiro em um sistema conjugado substrato/recipiente, com irrigação manual. Após 180 dias da semeadura, as mudas foram avaliadas quanto à altura, diâmetro de coleto, áreas foliares e radiculares, massa seca de brotações e raízes e teores de clorofilas a, b e clorofilas totais. O quociente de robustez e o índice de qualidade de Dickson (IQD) também foram calculados com base nas variáveis ​​biométricas. Os substratos F73 e CC55 promoveram maior crescimento de altura e diâmetro de coleto em comparação com outros substratos. Outras variáveis ​​relacionadas ao crescimento e qualidade das mudas e aos níveis de clorofila não diferiram em função dos substratos. A massa seca de raiz e massa seca total foram correlacionadas positivamente com o IQD. O diâmetro do coleto apresentou alta correlação positiva com a altura, a massa seca da parte aérea e a massa seca total das mudas de A.angustifolia.

Restoring native forests from Pinus radiata plantations: Effects of different harvesting treatments on the performance of planted seedlings of temperate tree species in central Chile

Extensive areas of native vegetation have been cleared to establish commercial exotic tree plantations in south-central Chile, a region known as a world biodiversity hotspot. Despite increasing societal demands to restore native forests in parts of the landscape, documented experiences for this form of restoration are lacking. We conducted a landscape-replicated experiment to test the influence of different harvesting treatments (clearcut, strip-cutting and unharvested control) on the early establishment of native tree species in 20-year-old Pinus radiata plantations. Group plantings of shade-intolerant (Nothofagus dombeyi; Nothofagus obliqua), semi-tolerant (Nothofagus alpina; Laurelia sempervirens) and shade–tolerant species (Aextoxicon punctatum; Cryptocarya alba) were established across the treatments, and seedling performance and water status were monitored during the first two growing seasons. Mean survival was significantly higher in the strip-cuttings (77%) and control (70%) than in the clearcuts (38%), while mean height and root collar diameter growth were significantly higher in the strip-cuttings (16 cm year−1; 0.2 cm year−1) and clearcuts (16 cm year−1; 0.2 cm year−1) than in the control (5 cm year−1; 0.1 cm year−1). Shade-intolerant and semi-tolerant species showed the highest growth responses to openings. Leaf water potential was significantly higher in seedlings in the strip-cuttings than those in the control and clearcuts, and stomatal conductance was significantly higher in the strip-cuttings and clearcuts than in the control. Higher seedling performances and lower water stress in the strip-cutting treatment suggest that partial canopy removal is a suitable method for artificial regeneration of native tree species with different shade tolerances for native forest restoration from P. radiata plantations.

Initial establishment of commercial tree species under enrichment planting in a Central Amazon secondary forest: Effects of silvicultural treatments

Enrichment planting has the potential to conserve wide areas of secondary forest in the Amazon. Therefore, it is necessary to understand the effects of silvicultural treatments applied to secondary forest management on the initial establishment of planted species. Enrichment planting was performed in a Central Amazon secondary forest to test whether the growth, mortality and presence of shoot borer attacks of six commercial trees species – in the first two years after planting – depend on canopy trees refinement and understory slashing. Six commercial tree species were planted under a gradient of light transmittance that was created by canopy trees refinement applied in six levels of basal area reduction (0; 20; 40; 60; 80 and 100%) and combined with two understory slashing levels (control and understory slashed). The effects of silvicultural treatments on root collar diameter and height growth (realized and relative), mortality and shoot borer attack were evaluated during the first and second year after planting. The relationships between realized growth and light transmittance were different among the species, but maximum growth was observed at high light transmittance for all species. Understory slashing slightly increased the response of realized growth to light transmittance. Species relative growth was strongly affected by light transmittance, but there was a reduced response in the second year after planting, particularly in the light-demanding pioneer species (Cedrela fissilis, Tabebuia rosea and Swietenia macrophylla). Pioneer species mortality was higher in deep shade (lowest transmittance) and was related to fast growth at full sun (highest transmittance) during the first, but not the second, year after planting. Shade-tolerant species (Hymenaea courbaril, Carapa guianensis and Bertholletia excelsa) have slower growth in full sun than pioneers, but only during the first year. Shoot borer attacks in Meliaceae species (C. fissilis, S. macrophylla and C. guianensis) occurred more frequently in high light transmittance and understory slashed environments but were absent in intermediary to low light transmittance and untreated understory. Thus, silvicultural treatments improve the initial establishment of commercial tree species in secondary forest enrichment planting sites. However, such findings should be analyzed considering the effects on growth, mortality and pest attacks during the seedling to juvenile tree development stages after planting.

Correlation of Morphological Characteristics of Nyamplung Seedling (Calophyllum inophyllum L) with The Performance at Field Condition

The aim of this research is to assess the correlation of morphological characteristics of nyamplung seedling (Calophyllum inophyllum L) on field growth of two years age after outplanting in Parungpanjang, Bogor. Three seedlots collected from Carita, Pangandaran and Purworejo were grown in seedbeds with different ages (four months and six months). The seedlings are mixed and grouped according to their height and root collar diameter. Each group of seedlings is divided into 5 height classes and each class is divided into two diameter classes, so there are 10 classes of seed morphology. The parameters of seedling were observed on sturdirness quotient, dry weight, root length, shoot-root ratio, and number of leaves. The seedlings were planted in randomized completely block design (three seeds origins, 10 morphological class, three blocks, 30 seedlings per block). Seedling survival, height, and root collar diameter growth were assessed on two years after outplanting. The result showed that morphological classification affected on seedling survival, height and root collar diameter growth. Seedling height and root collar diameter were significantly correlated with other parameters and also with field growth. Two-year-old Nyamplung on field can grow significantly if we use seedling with a height above 31 cm and a diameter more than 5.1 mm. In addition, the ratio of height and diameter and seed quality index are become important consideration in seed selection.

Correlation of Morphological Characteristics of Nyamplung Seedling (Calophyllum inophyllum L) with The Performance at Field Condition

The aim of this research is to assess the c orrelation of m orphological c haracteristics of nyamplung seedling ( Calophyllum inophyllum L ) on field growth of two years age after outplanting in Parungpanjang, Bogor. Three seedlots collected from Carita, Pangandaran and Purworejo were grown in seedbeds with different ages ( four months and six months). The seedlings are mixed and grouped according to their height and root collar diameter . Each group of seedlings is divided into 5 height classes and each class is divided into two diameter classes, so there are 10 classes of seed morphology. The parameters of seedling were observed on sturdirness quotient, dry weight, root length, shoot-root ratio, and number of leaves. The seedlings were planted in randomized completely block design ( three seed s origins, 10 morphological class, three blocks, 30 seedlings per block). Seedling survival, height, and root collar diameter growth were assessed on two years after outplanting. The result showed that morphological classification affected on seedling survival, height and root collar diameter growth. Seedling height and root collar diameter were significantly correlated with other parameters and also with field growth. Two-year-old Nyamplung on field can grow significantly if we use seedling with a height above 31 cm and a diameter more than 5.1 mm. In addition, the ratio of height and diameter and seed quality index are become important consideration in seed selection. Keywords: Calophyllum inophyllum , diameter, height, morphology, seedling quality