Jurnal Sylva Lestari

Assessing Water Absorption and Root-Shoot Dynamics of Native Philippine Tree Species for Flood Mitigation and Environmental Management

2025-02-03T17:06:35+07:00

Over the years, excessive stormwater run-off has been a primary environmental concern in almost every part of the world. This study aimed to assess the water absorption capacity and root-shoot ratio of the three native species, namely Vitex parviflora, Pterocarpus indicus, and Diospyrus discolor, in the Philippines. The study used an experimental design with a total number of 63 experimental seedlings. After over a month of transplanting, the researchers collected the data by uprooting 1 sample per box and recording its weight. The uprooted samples were then submerged into a container with enough water, and the plant waited until it absorbed enough water before being weighed again. Root and shoot ratio were also computed using its dry weight. The results showed a significant difference in terms of absorption rate between the three native species. V. parviflora garnered the highest water absorption rate, followed by P. indicus and D. discolor. Root-shoot ratio was highest in D. discolor while lowest in V. parviflora. No significant correlation was found between root and shoot biomass regarding water absorption capacity. These findings highlight the importance of selecting specific tree species for environmental management and flood mitigation efforts in the Philippines.

Keywords: biomass, native species, stormwater run-off, water absorption

Selecting a Suitable Synthesis of Industrial Hot Melt Nanostructured Polyurethane Adhesives for the Enhanced Bonding of MDF and PVC Veneers - A Review

2025-03-03T09:03:48+07:00

This review focuses on the synthesis and application of industrial hot-melt nanostructured polyurethane adhesives (HMPUAs) used for enhancing the bonding of medium-density fiberboard (MDF) with polyvinyl chloride (PVC) veneers. The use of PVC veneers has been identified as an effective approach to protect wood composite products, particularly MDF, due to its resistance to moisture, environmental conditions, and cost-effectiveness. However, achieving strong adhesion between PVC and MDF remains challenging due to differences in their chemical and structural properties. This study compares various synthesis methods of polyurethane adhesives, emphasizing the prepolymer method as the most efficient approach for producing high-performance HMPUAs. Key challenges include optimizing the isocyanate to hydroxyl group ratio (NCO/OH), selecting appropriate polyols, and incorporating suitable additives. The effects of nanoparticles, including nanosilica, nanolignin, phosphorus, nitrogen compounds, mica particles, and aluminum trihydrate, on the mechanical and thermal properties of polyurethane adhesives are thoroughly discussed. Furthermore, the challenges of achieving consistent adhesive performance, compatibility, and durability under varying environmental conditions are addressed. The findings of this review provide essential insights into improving the synthesis of one-component HMPUAs and enhancing their applicability in MDF-PVC veneer bonding.

Keywords: additives, hot melt adhesive, medium-density fiberboard, polyurethane, reactive resin

Growth Performance of Selected Bamboos in Secondary Forest and Riparian Ecosystems under Different Silvicultural Treatments

2025-03-04T11:41:05+07:00

This study was conducted in Nueva Vizcaya to evaluate the growth performance of two economically important erect bamboo species, Bambusa vulgaris and Bambusa spinosa, in secondary forest and riparian ecosystems under different silvicultural treatments. A factorial experiment was arranged in a Randomized Complete Block Design (RCBD) with three silvicultural treatments and three sampling plots. Each sampling plot contained 36 plantlets (18 B. spinosa and 18 B. vulgaris) for both ecosystem types. The field study lasted six months, with data collected biweekly. Growth parameters measured included percent survival, average height (cm), average diameter (mm), and number of shoots. Data were analyzed using repeated measures ANOVA in MINITAB and summarized with Excel pivot tables. The results revealed significant effects of silvicultural treatments and plot location on growth parameters. B. vulgaris exhibited more shoots than B. spinosa in the secondary forest. Ring weeding and cultivation (C2) resulted in a significantly higher number of shoots (1.85), followed by ring weeding with no cultivation (1.83), albeit fewer and shorter than those under no weeding and cultivation (1.72). Silvicultural management showed no significant correlation with other variables. A positive correlation between light intensity and growth was observed, with the highest correlation occurring at 4 pm. This pioneering study provides baseline data for monitoring the growth and performance of these bamboo species across distinct ecosystems. By offering comprehensive insights into their growth patterns and adaptability, the findings could inform sustainable management practices and conservation strategies for bamboo resources under varying environmental conditions.

Keywords: Bambusa spinosa, Bambusa vulgaris, riparian, secondary forest, silvicultural treatments

Evaluation of the Repeatability and Accuracy of RTK GNSS under Tree Canopy

2025-04-17T12:29:37+07:00

Using the Real Time Kinematic (RTK) GNSS (Global Navigation Satellite Systems) Method, one may precisely estimate a location on Earth in “real-time” to within a few centimeters. However, significant limitations remain, such as accuracy loss due to poor satellite sight (e.g., high satellite obstructions from tree canopy and dense urban areas). It usually takes time to resolve the ambiguities or, on many occasions, results in failure. Several satellite systems have been deployed in recent years besides GPS and GLONASS, such as Galileo, BeiDou, and other satellite systems. GNSS is the replacement word for GPS, GLONASS, Galileo, and BeiDou. Theoretically, this GNSS system would be more beneficial than previous systems such as GPS; issues with decreased position accuracy and limited satellite visibility (for example, in the presence of a tree canopy) may be resolved. This study aims to reduce integer ambiguity resolution time using RTK GNSS and examine RTK GNSS’s repeatability/accuracy in forested areas. The outcomes of GNSS positioning (compared with total station) in this study clearly showed improvement because of observing many satellites. The results suggest that the RTK GNSS system is preferred for surveying forested areas. This situation increases the accuracy of the RTK GNSS measurements and shortens the solution time for integer ambiguity. The horizontal component accuracy obtained in repeated RTK GNSS surveys in the forested areas remains 1–12 cm.

Keywords: accuracy, GNSS, precision, repeatability, Real Time Kinematic, tree canopy