Height Increment Research Articles

Predicting resin pockets and blemishes in radiata pine lumber from log properties

Background: Resin pockets and blemishes in pruned logs of radiata pine (Pinus radiata D.Don) can reduce the value of clear and moulding grades of lumber. External resin features (ERF) on the bark of the logs have proved an effective method of predicting the incidence of resin pockets in the lumber. Resin canals have been associated with resin blemishes in radiata pine, and could prove useful in improving the prediction of the grade recovery of lumber. Methods: Pruned butt logs of radiata pine trees from two forests in the North Island, New Zealand, were selected for low, moderate, and severe levels of external resin features (ERF) on the bark, and for low, average, and high resin canal diameter, frequency and brightness from breast height increment cores. The relationships were evaluated between these properties, and the lumber resin features and grade recovery of the logs. Results: The number of resin pockets, the blemish rating, and the percentage of boards with resin streaks and resinous heartwood increased, and the recovery of clears and moulding grade boards and the lumber value declined, with the severity of the ERF class of the logs. Multiple regression models gave good predictions of the grade recovery and loss of lumber value, using the log ERF class, volume, heartwood content, and number of Type 1 resin pockets on the ends of the logs, as independent variables. The resin canal properties did not improve the regression models. Resin blemishes were associated with Type 2 resin pockets, and were more frequent in the forest where false growth rings were present. This suggests the constitutive resin flow from resin canals, rather than the resin canal size and frequency, is more important in determining the incidence of resin blemishes. Conclusions: The prediction of the grade recovery of lumber using the ERFs of radiata pine logs, was supplemented by the log volume, heartwood content and number of Type 1 resin pockets on the ends of the logs. The environmental factors that drive the constitutive resin enrichment of resin canals, such as drought conditions that give rise to false growth rings, could be useful in improving the prediction of grade recovery for forest stands.

Protocolo eficiente para aumentar el porcentaje de prendimiento en injertos de Pinus greggii Engelm. var. australis Donahue et López

Introduction: Grafted plants of conifers are used in the establishment of clonal seed orchards, but with the methodology currently used, unsatisfactory results are reported. Objective: To compare grafting and growth of Pinus greggii var. australis scion from nursery and field stock plants grafted on four rootstocks. Materials and methods: Scions of P. greggii Engelm. var. australis Donahue et López, collected from nursery stock plants (NSSP) and field trees (FSSP), were divided into terminal bud and basal segment, and grafted onto P. greggii var. australis, P. patula Schiede ex Schltdl. et Cham., P. teocote Schiede ex Schltdl. et Cham. and P. leiophylla Schiede ex Schltdl. et Cham. Percentage of grafting, height increment, diameter, scion-rootstock ratio and number of shoots (NS) were evaluated. Height and diameter increment data were subjected to an ANOVA and NS was analyzed with Poisson regression. Results and discussion: Grafting ranged from 93 to 100 %. The greatest increase in height was reported for P. teocote (14 cm) with scion from the terminal shoot of the nursery plant, while the combination P. greggii / P. leiophylla had the best scion-rootstock ratio with a value of 1. The highest NS was recorded with scion from the basal segment of NSSP. Getting two types of scions from one scion made the use of vegetative material more efficient. Conclusions: The use of nursery stock plants, 15-month-old rootstock, and two types of scions allowed having grafted plants in three months. The methodology developed was efficient, cost-effective and fast.

ADVANCEMENT IN OIL PALM PLANTING MATERIALS IN THE FUTURE

The development of shorter planting materials based on MPOB Nigerian population 12 and E.oleifera x E.guineensis inter-specific hybrids is highlighted in this paper. The progeny test results of Nigerian Population 12 with selected Deli duras showed that the DxP oil yield ranges from 8.1-8.5 tonnes per hectare per year. The height increment of DxP is 33-39 cm per year. In comparison, the height increment of Deli x AVROS is about 60 cm per annum. In Colombia where DxP commercial plantations are devastated by bud rot disease, Cinepalma demonstrated that application of naphthalene acetic acid (NAA) increased the oil yield of inter-specific hybrids which are tolerant to the disease. It was demonstrated in commercial plantations that applying NAA can produce more than 40 tonnes fresh fruit bunch (FFB) per hectare per year, with an extraction rate of about 27 per cent giving >10 tonnes oleic oil per hectare. The tissue culture labs in Kuala Lumpur-Kepong (KLK) and Asian Agri are also cloning their elite Deli duras and pisiferas to create semi- and bi- seeds. Applied Agricultural Resources (AAR) is the largest semi-clonal seed producer in Malaysia, and produces about 8 million per year and sells the seeds at a premium. A number of plantation companies in Malaysia and Indonesia have initiated programmes to produce Ganoderma tolerant planting material. Companies have adopted an integrated disease management (IDM) approach, covering land preparation, planting tolerant varieties, use bioagents, early detection, and removal of infected materials. Asian Agri AA TOPAZ GT variety, partially tolerant to Ganoderma, has an average oil yield potential of 9.2 tonnes crude palm oil (CPO) per hectare per year. Digitalisation refers to the process of integrating advanced digital technologies such as artificial intelligence (AI), big data, robotics, unmanned aerial vehicle (UAV), sensors, and communication networks, all connected through Internet of Things (IoT) into farm production system. A major breakthrough was achieved by the oil palm Genome Programme at the Malaysian Palm Oil Board (MPOB), where the identification of the gene controlling Shell has made it possible to identify and differentiate dura, tenera and pisifera at the nursery stage. This led to the first molecular diagnostic assay known as SureSawitTMSHELL, which the breeders can use to identify and isolate dura, tenera and pisifera seedlings from TxT and TxP breeding crosses. The kit can be used for identification of dura and pisifera contaminants in the nursery and more recently at the seed production facility. The planter has an important role to help realise the full potential of planting materials. The planter’s role starts from receipt of germinated seeds to field planting. The planter is assigned to monitor ripeness standard, harvesting, loose fruit collection and managing of workers, all of which are major tasks to ensure productivity. Climate change is real and we have to confront drought and floods more frequently. In order to minimise the impact of drought, it is advisable to plant planting materials with high bunch number. MPOB has collected oil palm germplasm in the dry areas of Nigeria. This germplasm has attributes such as high bunch number, low bunch weight and high chlorophyll content in the leaves. These traits are useful to develop drought tolerant planting materials.

Stability of inner dump slope under coal pillar support: case study in an open-pit coal mine

The stability of an inner dump slope was investigated under the effect of coal pillar support considering the development position of dumping. Based on the instability mechanism and load distribution characteristics of the supporting coal pillar, the three-dimensional mechanical effects of the supporting coal pillar are characterized. Using the two-dimensional equivalent principle and the residual thrust method, the stability of the inner dump slope was analyzed under the effect of pillar support at different dump development positions. The quantitative effects of various factors on the inner dump slope stability were revealed, and the coal pillar shape parameters were optimized through numerical simulations. The results indicate that the slope stability coefficient is linearly related to the top width and height of the coal pillar, slope angle, and base inclination angle, and has an exponential relation with the coal pillar strike length and slope height increment. There are quadratic and absolute value relations with the coal pillar outer and the inner bottom angle, respectively. The top width of the coal pillar in the inner dump of Shengli East No.2 open-pit coal mine should be at a level of + 824 m, and the optimal top width and height are 15 and 36.7 m, respectively. The instability mechanism of the supporting and retaining coal pillar obtained by numerical simulations and the stability of the inner dump are in good agreement with the theoretical analysis. Our results provide a theoretical basis for the design, treatment, and safe implementation of similar open-pit mine slope engineering.

Stimulation, Reduction and Compensation Growth, and Variable Phenological Responses to Spring and/or Summer–Autumn Warming in Corylus Taxa and Cornus sanguinea L.

Understanding species-specific responses to climate change allows a better assessment of the possible impact of global warming on forest growth. We studied the responses of the shrub species Corylus avellana L., Corylus maxima Mill. and intermediate forms, together stated as the Corylus taxa, and Cornus sanguinea L. upon periodically elevated temperatures in spring and/or in summer–autumn. Experiments were performed in a common garden, with Belgian and Pyrenean provenances for Corylus avellana and Cornus sanguinea. In the Corylus taxa, a warmer spring resulted in a reduction in height and diameter growth. Remarkably, the reduced diameter increment was restored with full compensation in the following year. The height increment for Cornus sanguinea was larger upon a warmer summer–autumn, concurring with a later leaf senescence. Our results suggest that Corylus is more sensitive to spring warming, influencing growth negatively, whereas Cornus is more sensitive to summer–autumn warming, influencing height growth positively. These deviating responses can be explained, at least partly, by their diverging ecological niches, with the Corylus taxa being more shade-tolerant compared to Cornus sanguinea. The warm spring conditions advanced bud burst in all studied taxa, whereas the warm summer–autumn advanced leaf senescence but prolonged its duration in the Corylus taxa, as well as delayed this phenophase in Cornus sanguinea. Little to no after-effects of the temperature treatments were detected. Although Corylus avellana and Cornus sanguinea plants originated from similar origins, their growth and phenological responses in the common garden diverged, with Corylus being more stable and Cornus displaying more variation between the Belgian and Pyrenean provenances.

Bearing Capacity Calculation of Soft Foundation of Waste Dumps—A Case of Open-Pit Mine

For a waste dump with soft foundation, the foundation bearing capacity has an important impact on slope stability. According to the load distribution and stress characteristics of a waste dump, combining the gravity load of the triangular slope of the waste dump and the passive Earth pressure exerted by the foundation soil with an improved Plandtl formula, the foundation bearing capacity and the ultimate pile height of a waste dump are calculated and determined. The concept of foundation bearing capacity of a waste dump is redefined, that is, the ultimate pile height corresponding to a certain slope angle. A method for determining the ultimate pile height of a waste dump based on the slope angle of the waste dump is proposed, and the relation function between dump slope angle and waste height is established. The results show that the sliding moment increment (∆MS) caused by the gravity load of the triangular slope after waste increase is positively proportional to the pile height increment (∆H); the anti-sliding moment increment (∆MAS) is positively proportional to or positively correlated with the pile height increment (∆H); the slope angle of the waste dump decreases with the increase of the thickness of soft bedrocks, and the smaller thickness of soft bedrocks is more favorable to the ultimate pile height of the waste dump. The research results can provide reference for the calculation of the bearing capacity of soft foundation and the optimal design of slope shape of waste dumps.

Assessment of the effect of stand density on the height growth of Scots pine using repeated ALS data

• Repeated ALS allows detecting the height increment variation influenced by stand density. • Higher stand density stimulate height growth, particularly on most productive sites. • Repeated ALS data allows developing density-dependent top height growth models. The spread of remote sensing technologies allows for continuous and precise mapping of forest ecosystem attributes over large areas. One of the most important attributes of a forest ecosystem is site productivity, an essential determinant of resource availability. Knowledge of site productivity is crucial for sustainable forest management because it is the basis for predictions of future forest growth and is fundamental to long-term planning in forestry. Models of forest dynamics allow us to better understand the functioning of forest ecosystems and to assess the provision of ecosystem services. However, discussions on the factors affecting forest growth are ongoing. Previous research has not clarified the influence of stand density on the height increment of trees. Consequently, this uncertainty leads to inconsistent predictions for stand growth and nonoptimal forest-management decisions. We aimed to analyse the effect of stand density on top height (TH) growth and the development of the TH growth model for Scots pine based on bitemporal ALS measurements. We applied repeated ALS observations from two acquisitions (2011, 2019) to fit a density-sensitive TH growth model. We found that stand density affected the TH growth of Scots pine. A higher stand density stimulated TH growth, particularly in productive sites showing a TH increment of about 10%. We demonstrated the usefulness of bitemporal ALS measurements for developing a TH growth model for Scots pine considering stand density. We found that the predictive accuracy of the TH increment increased when stand density was considered.

Temporal stability of stratifications using different dendrometric variables and geostatistical interpolation

Stratifying a forest results in more precise and cheaper inventories. This study aimed to select the stratifying variable that estimates more precise and stable inventory over the years for a eucalyptus plantation in Minas Gerais state, Brazil. The continuous forest inventory was performed annually from 2.7 to 6.8 years, and based on the field measurements, arithmetic mean diameter (d), height (h), dominant height (Hdom), basal area (G), volume (V), and mean annual increment in volume (MAI) were calculated. Semivariograms were generated and the exponential, spherical and Gaussian models were fit for each stratifying variable for each measurement date. The models were assessed by the reduced mean error and its deviation, being the exponential model selected. Maps showing the spatial distribution of all variables were generated for each measurement age, using ordinary kriging. Next, the study area was divided in four strata based on each stratifying variable for each measurement age. The stability of each stratifying variables for each measurement age were assessed by: 1) coincident strata area; 2) stability of total strata area; 3) plot permanency on each stratum; and 4) inventory error using stratified random sampling procedures. All variables in all ages presented spatial dependence structure. G and Hdom were the stratifying variables that generated the most and the least coincident strata area over the years, respectively. G and height (h and Hdom) were the stratifying variables yielding the least and most plot stratum changes, respectively. The same trend was observed for the total strata area stability. Stratifying based on MAI and V yielded the smaller inventory error, and h and Hdom yielded the largest. G was selected as the best stratifying variable because it yielded small inventory errors and was the most stable variable in terms of coincident strata area, total strata area and plot stratum changes over the years.

Climate and ungulate browsing impair regeneration dynamics in spruce-fir-beech forests in the French Alps

Key messageDifferent components of water balance and temperature reduce density and height growth of saplings of Picea abies (L.) H. Karst (Norway spruce), Abies alba Mill. (silver fir) and Fagus sylvatica L. (European beech) in mixed uneven-aged forests in the French Alps and Jura mountains. Ungulate browsing is an additional pressure on fir and beech that could jeopardise the renewal of these species in the future.ContextThe uncertainty in tree recruitment rates raises questions about the factors affecting regeneration processes in forests. Factors such as climate, light, competition and ungulate browsing pressure may play an important role in determining regeneration, forest structures and thus future forest composition.AimsThe objective of this study was to quantify sapling densities and height increments of spruce, fir and beech and to identify dominant environmental variables influencing them in mixed uneven-aged forests in the French Alps and Jura mountains.MethodsSapling height increment and density were recorded in 152 plots, and non-linear mixed models were obtained to establish relations between them and environmental factors known to affect regeneration, namely altitude, slope, aspect, canopy openness, soil characteristics, temperature, precipitation and ungulate browsing.ResultsRegeneration density, varying from 0 to 7 saplings per m 2, decreased with sapling height and was also negatively affected for spruce by PET, but positively for fir by precipitation and for beech by mean annual soil water content. Height increment reached up to 50 cm annually, increasing with sapling height and canopy openness and decreasing under high maximum summer temperatures for spruce and beech. The statistical effect of different environmental variables varied slightly among species but trends were quite similar. Additionally, ungulate browsing was high, with fir being the most intensely browsed, followed closely by beech, while spruce was rarely browsed.ConclusionsAll these results suggest that more temperature warming and a decrease in water availability could negatively impact sapling growth and density in the three species, with possible reduction of forest renewal fluxes. The observed increase of ungulate populations leading to increased browsing could be particularly detrimental to fir saplings.

Meranti (Shorea sp.) Biochar Application Method on the Growth of Sengon (Falcataria moluccana) as a Solution of Phosphorus Crisis

Phosphorus (P) is a limiting nutrient mined from non-renewable sources. P is needed to stimulate trees growth in a forest plantation. P-fertilizer addition in the tropical forest field causes P-leaching flux to watershed and induces eutrophication. The high C contained in meranti (Shorea sp.) biochar can avoid the P-leaching process in the soil with a strategic application method. However, the biochar application method is poorly examined. This research aimed to develop a biochar application method to sequestrate P from the environment and examine its effect on the growth of sengon (Falcataria moluccana). Shorea sp. biochar pyrolyzed at 400 °C and 600 °C were added at a dosage of 0 t ha−1, 25 t ha−1, and 50 t ha−1 for six months in the field. The biochar was placed 20 cm under topsoil without soil mixing. This application method significantly increased total P in the soil without any P-fertilizer addition. The results showed that biochar pyrolyzed at 600 °C and a dosage of 25 t ha−1 increased the total P in the soil and CEC by 192.2 mg kg−1 and 25.98 me 100 g−1, respectively. Biochar with a higher pyrolysis temperature increased higher soil pH. In contrast, the higher dosage increased organic-C higher than the lower dosage application. The most significant P-uptake, height, and diameter increments on F.moluccana were achieved using Shorea sp. biochar pyrolyzed at 600 °C with a dosage of 25 t ha−1 by 0.42 mg kg−1, 222 cm, and 2.75 cm, respectively. The total P in the soil positively correlated with the P-uptake of F. moluccana. Furthermore, using the biochar application method P could be absorbed to the biochar layer and desorbed to the topsoil. Consequently, the biochar application method together with P-fertilizer addition could increase the availability of P in the soil and decrease P-leaching to the environment.

Growth Hormone and Thyroid Function in Children With Attention Deficit Hyperactivity Disorder Undergoing Drug Therapy.

The trends in hormone indices of children with attention deficit hyperactivity disorder (ADHD) who received long-term medication treatment remains controversial. This prospective study aimed to examine the changes in the growth hormone and thyroid hormone systems among children with ADHD undergoing various medication treatments. In total, 118 children who were diagnosed with ADHD and were drug-naive were observed naturalistically over 12 months. Of them, 22 did not receive any medication, while 39, 40, and 17 were treated with low doses of short-acting methylphenidate (MPH) (14 ± 6.7 mg/day), osmotic-release oral system (OROS) long-acting MPH (32 ± 9.6 mg/day), and atomoxetine (29.2 ± 9.7 mg/day), respectively. Blood samples were obtained at both the baseline and the endpoint (month 12) to measure serum levels of insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free T4. Trends for IGF-1, IGFBP-3, prolactin, TSH, T3, T4, and free T4 levels were similar among the 4 groups. Changes in serum levels of IGF-1 were positively correlated with changes in height and weight of all the children with ADHD. However, patients who received MPH treatment had less body weight gain than the nonmedicated group. The ratio of MPH doses to body weight was inversely correlated with the increment in height. There were no changes in thyroid or growth hormones associated with the low doses of ADHD medications used in this study within 1 year's duration. Nonetheless, patients' growth and the appropriateness of drug dosage should be closely monitored.

Investigation on the Cause-Effect Relationships between the Process Parameters and the Resulting Geometric Properties for Wire-Based Coaxial Laser Metal Deposition

Coaxial Laser Metal Deposition with wire (LMD-w) is a valuable complement to the already established Additive Manufacturing processes in production because it allows a direction-independent process with high deposition rates and high deposition accuracy. However, there is a lack of knowledge regarding the adjustment of the process parameters during process development to build defect-free parts. Therefore, in this work, a process development for coaxial LMD-w was conducted using an aluminum wire AlMg4,5MnZr and a stainless steel wire AISI 316L. At first, the boundaries for parameter combinations that led to a defect-free process were identified. The proportion between the process parameters energy per unit length and speed ratio proved crucial for a defect-free process. Then, the influence of the process parameters on the height and width of single beads for both materials was analyzed using a regression analysis. It was shown that linear models are suitable for describing the correlation between the process parameters and the dimensions of the beads. Lastly, a material-independent formula is presented to calculate the height increment per layer needed for an additive process. For future studies, the results of this work will be an aid for process development with different materials.

Theoretical Analysis of the Flower‐Shaped Pattern Distribution in Self‐Catalyzed GaN Nanorod

The strain‐induced growth of self‐induced GaN nanorods (NRs) on the sapphire substrate is investigated experimentally. From cathodoluminescence (CL) results, it is noticed that the distributions of the flower‐shaped pattern are varied with the increment in NR height. Based on the experimental observation, a simulation model for NR formation is established, which is in good agreement with the experimental data. Then, the preferred nucleation position for adatom deposition in the NR growth process is theoretically analyzed. Finally, an equilibrium growth condition for the vapor–solid (VS) and vapor–liquid–solid (VLS) mechanism of GaN NR growth is proposed.

Synchronized Efficacy and Mechanism of Alkaline Fertilizer and Biocontrol Fungi for Fusariumoxysporum f. sp. cubense Tropical Race 4.

The purpose of this study was to determine the effect and mechanism of alkaline fertilizer, bio-control fungi, and their synergistic application on control of Fusarium Tr4 incidence. Synchronized use of the alkaline fertilizer and biocontrol fungi eliminates rhizome browning and reduces the incidence rate of banana Fusarium wilt. The incidence of yellow leaves (ratio of yellow leaf to total leaf) and disease index in +Foc Tr4 CF treatment were the same (65%), while incidence of yellow leaves and disease index in +Foc Tr4 AFBCF were 31% and 33%, respectively. Under the stress of Foc Tr4 infection, the synergistic utilization of the alkaline fertilizer and biocontrol fungi would raise the activities of peroxidase, catalase and superoxide dismutase in banana roots. The root activity of banana was also increased. As a result, the banana height and stem diameter increments, shoot and root dry weight, accumulation of N, P and K in banana plants had been increased. The efficacy of the synergistic application of alkaline fertilizer and biocontrol fungi was not only reducing Foc Tr4 pathogen colonization and distribution in banana plants, but also preventing tylosis formation in vascular vessel effectively. Therefore, the normal transport of water and nutrients between underground and aboveground is ensured.

Vibration-induced segregation characteristics of binary pebble beds in confined containers

This paper presents the study of the segregation characteristics of bi-disperse mixed pebble beds under different confined conditions and vibration conditions by the Discrete Element Method. The Lacey index and the λ index are used to evaluate the degree of particle mixing or segregation. Results show that confined containers can suppress the segregation of the pebble beds when the top free space height is below a threshold. Further simulation reveals that this threshold of the free space height is related to the maximum bed height increment in an unconfined state and impacted by the vibration amplitude and frequency. However, the particle diameter ratio as well as the container shape and size seem to have a limited effect on the threshold. These findings are helpful to clarify the suppression effect of container confinement on the pebble bed segregation and its main resulting factors, and hence provide solutions to controlling vibration-induced segregation.

Characterization of native plant growth-promoting bacteria (PGPB) and their effect on the development of maize (Zea Mays L.)

Maize (Zea mays L.) is one of the most important cereals for Mexico and humanity. The Yaqui Valley -located in the northwest of Mexico- is one of the most important agricultural regions worldwide, it is characterized by an indiscriminate use of inorganic fertilizers for improving crop yields, leading to an increased environmental and economic cost of maize production. Here, a morphological, metabolic, and molecular characterization of native bacteria associated with maize rhizosphere was carried out, and then positive effects of bacterial inoculation to plants under greenhouse conditions were evaluated. The evaluated strains were taxonomically affiliated –based on the 16S rRNA gene- as Bacillus sp. (13B41), Advenella incenata (22A67), Pantoea dispersa (22B45), and Rhizobium pusense (31B11). All of these strains were able to synthesize indoles, produce siderophores, and solubilize phosphates. The individual inoculation of these strains to maize plants showed a significant increment (compared to un-inoculated plants) in height (35-40 %), shoot dry weight (244-289 %), root dry weight (99-137 %), and SPAD values (40- 47 %). The native bacteria associated with maize in the Yaqui Valley are a promising alternative to promote the growth of their host plant, and contribute to a sustainable maize production.

Comparison of Juvenile, Drought Tolerant Black Locust (Robinia pseudoacacia L.) Clones with Regard to Plant Physiology and Growth Characteristics in Eastern Hungary: Early Evaluation

(1) Background: The aim of our study is to present the results of initial growth and plant physiology studies of newly selected, vegetative propagated black locust clones, with a view to assess their suitability for the establishment of fast growing tree plantations for the production of high quality timber in marginal (semi-arid) sites. (2) Methods: In the spring (May) and autumn (November) of 2021, full inventories were carried out in the black locust industrial tree plantation. The Normalized Difference Vegetation Index (NDVI) values were observed monthly from May to September 2021. For measuring the assimilation parameters the net assimilation, transpiration, stomatal conductance, intercellular CO2 concentration, and other physiological parameters were recorded. (3) Results: Robinia pseudoacacia ‘NK2’ clone showed the highest assimilation rate and it produced the most height increment in the growing season, from May 2021 to November 2021. The discriminant analysis classified successfully the black locust clones, 86.7% of original grouped cases were correctly classified. (4) Conclusions: The study of industrial tree plantations is of great practical importance. As black locust can tolerate even marginal site conditions, the lack of timber can be reduced in the future by establishing black locust industrial tree plantations. To be able to produce good quality industrial wood on the plantations, it is essential to study the phytophysiological properties of the trees (biomass production, vegetation activity of plants, chlorophyll content, photosynthetic activity) in addition to the traditional stand full inventories.

SEEDLING AND GROWTH OF Rhizophora mangle L. PROPAGULES AT A RESTORATION SITE (APA DE GUAPI-MIRIM - RJ)

One of the biggest mangrove forests in Rio de Janeiro is located at Guanabara Bay. However, a large part of this ecosystem is currently suppressed and only 1/3 of the original 261.90 km² of mangrove vegetation can be observed. Thus, several conservation and management actions are conducted in this ecosystem. Studying plantations and other restoration strategies for this biome is important to understand the dynamics of this ecosystem and enhance such strategies. Size can be one of the most important characteristics for propagules success. Some studies state that larger seedlings can resist more and have greater survival than smaller seedlings. Therefore, this study aims to analyze the germination and development of Rhizophora mangle L. propagules at an in situ plantation in the mangroves of the Guapi-Mirim Environmental Protection Area. A total of nine plots were delimited with spacing of 4 meters by 1 meter each in which Rhizophora mangle propagules were separated into small and large groups and planted. Their germination and development were subsequently monitored for a period of 6 months. The diameter, height and initial weight of the propagules and the increase in height and diameter at 76, 93 and 154 days after planting were measured. Periodic observations were made approximately every 20 days in order to quantify the rate and type of mortality (predation, water current carriage and drying) and to monitor time (in days) of pairs of leaves opening. There were no differences between the propagules according to the size for the opening time of leaf pairs, nor for the mortality rate. The increments in diameter and height were larger for the small propagules in the first development periods, but not in the last ones. The large and small propagules did not show significant differences in diameter or height at 154 days. There was high mortality of small propagules due to predation and/or water current carriage, while the mortality for large propagules was higher due to desiccation. The results generally suggest there is no difference in the survival and development of the propagules related to size, as they are more affected by local ecological conditions.

Exploring The Potency of Microalgae-Based Biofertilizer and Its Impact on Oil Palm Seedlings Growth

Indonesia is a major producer of palm oil. Consequently, the use of chemical fertilizers has become more extensive. Microalgae represent a potential alternative for enhancing and protecting crops based on their cell elements. This study applies dry biomass or liquid culture formulation of the green microalgae Haematococcus pluvialis to the rhizosphere of oil palm pre-nursery as a biofertilizer. Soil application of microalgae biomass of 0.5 g/l (MA) or liquid culture of 10% (v/v) (BCMA) is carried out to assess its effects on 4-months-old oil palm at the nursery stage. The compatibility test between microalgae and bio fungicide agents in agricultural practices, Trichoderma spp., is also tested on both microalgae formulations. The result shows that both microalgae biomass and liquid culture, alone or combined with Trichoderma spp., give a better growth performance to the oil palm. The application of MA and BCMA result in a maximum increment of plant height, leaves count, and chlorophyll content. Furthermore, the application of BCMA gives better oil palm growth performance, which may probably be influenced by the accessibility of nutrients for microalgae growth. The study reveals that soil application of microalgae as biofertilizers can improve oil palm growth performance.

Phenotypic Plasticity of Cunninghamialanceolata (Lamb.) Hook. Seedlings in Response to Varied Light Quality Treatments

Effects of light quality on phenotypic plasticity in Cunninghamialanceolata (Lamb.) Hook. seedlings during growth and development, and the underlying mechanisms, were investigated. The seedlings showed distinct morphological adjustments when exposed to an equal photosynthetic photon flux density (400 μmol·m−2·s−1) of different light qualities: monochromatic blue (BL), monochromatic red (RL), monochromatic far-red (FrL), mixed RL and FrL at 1:1 (RFr1:1L), mixed RL and FrL at 1:2 (RFr1:2L), and multi-wavelength white (WL, control). Compared with WL, FrL and BL significantly promoted height increment. However, BL was unfavorable for root growth. The seedling biomass was lower and the root-to-shoot ratio was smaller under BL. RL promoted leaf area enlargement, root growth, axillary bud number, and increased the root-to-shoot ratio, but inhibited stem elongation. Low R/Fr ratios or increased FrL proportion increased seedling stem elongation. The seedling growth under RFr1:1L treatment was poorer than that under other treatments; however, the number of axillary buds was the highest. The plasticity of leaf morphology traits was lower in different treatments, and that of axillary bud traits was crucial in the adaptation of C. lanceolata to light quality. Precise management of light quality and wavelength in controlled environments may maximize the economic efficiency of forest production and enhance its quality.