Journal of Tropical Forest Science (JTFS)

ENERGY POTENTIAL OF PROSOPIS JULIFLORA WOOD IN BRAZILIAN CAATINGA BIOME

Mon, 10 Feb 2025 00:00:00 +0000

Prosopis juliflora (SW.) DC, an invasive exotic plant with energy potential was introduced in rural areas in northeastern Brazil as animal food and timber use. The objective was to evaluate the energy potential of wood from P. juliflora for charcoal production and quality of this plant material, based in the PMQ 3-03 standard, produced in the Caatinga biome, semiarid region of Sergipe, Brazil. Basic density and moisture along the trunk, immediate chemical analysis, structural chemical analysis, higher calorific value wood of gravimetric yield, immediate chemical analysis, bulk density, and higher calorific value of the charcoal of this plant were determined. The volatile material content, fixed carbon, ash, lignin, holocellulose, extractives, and calorific value of P. juliflora wood were 76.61%, 22.28%, 1.11%, 32.55%, 66.52%, 0.83% and 19.70 MJ/kg, respectively. Values of gravimetric performance, pyroligneous liquid, non-condensable gases, volatile materials, fixed carbon, ash, bulk density, calorific value of P. juliflora charcoal were 37.95%, 33.96%, 28.08%, 29.60%, 68.19%, 2.20%, 204 kg m-³ and 27.47 MJ kg^-1, respectively. The values of wood and charcoal of P. juliflora indicate its potential for energy production with its properties gathering the PMQ 3-03 standard for domestic use
in rural properties.

WATER-RETENTION OF THE LITTER LAYER OF TREE-BASED SYSTEMS IN MT. PANGASUGAN, PHILIPPINES

Auguis MMA, Baldos AP, Peque DP — Mon, 10 Feb 2025 00:00:00 +0000

Tropical rainforests are frequently characterised by elevated temperatures and increased precipitation, which contribute to accelerated rates of soil erosion and leaching, hence, the key problems revolve around the loss of soil and water. The study evaluated the water-retention properties of the litter layer of five tree-based systems, natural forest, rainforestation site, narra plantation, mahogany plantation, and abandoned kaingin site in Mt. Pangasugan. Though the maximum water-holding capacity of the total litter layer and of the undecomposed litter layer did not vary across the five tree-based land covers, the maximum water retention capacity, which had the same trend with that of the effective water-retention capacity, were significantly higher in both the mahogany and narra plantations. Changes over time in the water-holding capacity were similar in the natural forest (7169 g kg^-1), the narra plantation (6891 g kg^-1), and the mahogany plantation (6427 g kg^-1). It is recommended to strengthen restoration and conservation efforts of natural forests to preserve the highly desirable hydrological properties of their litter layer. In addition, the use of mahogany and narra in tree plantation development show potential in forest restoration projects for soil and water conservation.

PHYSICOCHEMICAL, MECHANICAL AND THERMAL PROPERTIES EVALUATION OF BIOFUEL PELLETS FROM SAGO BARK AND ACACIA MANGIUM WASTES

Mon, 10 Feb 2025 00:00:00 +0000

The demand for raw materials for biofuel pellet is growing, causing an increase in the costs of purchase and production. Fuel pellet is one of the solid fuels that can overcome the shortcomings of energy crisis. Therefore, studies on the potential of various biomass sources as a raw material is essential to fulfil the demand. The objective of this study is to determine the energy properties of pellet produced from sago and Acacia mangium wastes and their mixtures. The influence of pelletisation on physical, mechanical and thermal characteristics of pellet were properly investigated. The pellets produced were found characteristically to have a higher calorific value (17.5–18.3 MJ kg^-1) which is comparable to the European (EN) (>16.5–19 MJ kg^-1) and Korean standards (>4300 kCal kg^-1) requirements. The optimal properties of biofuel pellets with a sago bark content of 50% and less, such as durability (97.5–99.3%), ash (1.42–1.43%), sulphur (0.04%) and chlorine (0.08–0.17%) contents, were found to be better compared to biofuel pellets of higher sago bark content. These findings satisfied the international EN and Korean standards for export market. The current study demonstrated the potential of producing sustainable energy sources from the biomass mixture of sago and A. mangium, which may prove to be a competitive substitute for fossil fuels.

FLORAL BIOLOGY AND POLLINATION MECHANISM OF SALACCA VERMICULARIS BECC. (ARECACEAE: CALAMEAE)

Ng WS, Wong SY — Mon, 10 Feb 2025 00:00:00 +0000

Salacca (Arecaceae), a genus of palms with 23 accepted species, has its centre of diversity in Borneo. Salacca vermicularis Becc. which is endemic to Borneo, has, despite its edible fruits, has never been studied concerning its floral biology and pollination mechanisms. In this study, the phenology, floral rewards, floral visitors, and possible seed dispersal agents of S. vermicularis were investigated, and experiments performed on the breeding mechanisms of S. vermicularis. Anthesis in staminate flowers begins around noon and persists until early morning on the second day whilst anthesis in pistillate flowers begins around evening and may take up to 40 hours to fully bloom. Floral scent was present throughout the anthesis for staminate and pistillate plants. Apomixis is not present in this species. Several insect visitors were observed, namely Heterotrigona (Apidae) sp. as well as members of Curculionidae, Sciaridae, Formicidae, and Acaridae. Three species of visitors are likely the dispersal agents of S. vermicularis, namely Hystrix sp. (Hystricidae: Hystricinae), Tragulus sp. (Tragulidae) and Lariscus insignis (Sciuridae: Callosciurinae). A mongoose (Herspetidae) was observed foraging nearby but is unlikely as a dispersal agent.

SHEAR CAPACITY PREDICTION OF ACACIA MANGIUM CROSSLAMINATED TIMBER UNDER OUT-OF-PLANE BENDING

Kundari R, Achmad B, Halwan Alfisa S, Buan A — Mon, 10 Feb 2025 00:00:00 +0000

The popularity of cross-laminated timber (CLT) in construction has increased globally. In Indonesia, effort has been made to utilise local wood such as Acacia mangium in CLT production. The characteristics and properties of acacia CLT have not been studied in depth. Our study determined the shear capacity of short-span acacia CLT panels subjected to out-of-plane three-point bending tests and evaluated selected models (shear analogy method, gamma method, simplified composite beam method, and simple beam theory) in their ability to accurately estimate shear capacity. The simple beam theory (CSA086-14) gave predicted shear capacity values closest to the experimental results for three-layer acacia CLT samples (14.05 kN and 18.45 kN vs 13.7 kN and 18.06 kN for the 51 and 67 mm-thick panel samples respectively).

EVALUATING THE PLANT COMMUNITY PATTERNS IN MANTANANI BESAR ISLAND USING GIS AND PHYTOSOCIOLOGICAL SURVEY

Yuta I, Gisil J, Charles SV, Liew T-S — Mon, 10 Feb 2025 00:00:00 +0000

Mantanani Besar Island, in Kota Belud, Sabah, Malaysia, is both a tourist site and an important ecological site for many species. Despite the ecological importance, information on the distribution of plant species remains limited. This study aims to fill this gap by examining community patterns using vegetation mapping and a phytosociological survey. Based on our spatial analysis, approximately 84% of this island’s surface area is covered by forests, categorised into two distinct types: inland and coastal forest. Further investigation based, 55 quadrat plots (10m × 10m) that were randomly established in the classified forested area confirmed 66 species, representing 63 genera and 38 families. Two of the 66 recorded species were listed in the IUCN and Malaysia Plant Red Lists. The ANOSIM and Mantel’s tests revealed four plant community types in the island’s forested areas. Our survey the first comprehensive plant species checklist and community patterns on the island. We also concluded that combining both methods is beneficial for designing vegetation mapping.

EFFECTS OF SOIL NUTRIENT AVAILABILITY ON ECTOMYCORRHIZAL COMMUNITIES’ DISTRIBUTION IN TWO DIPTEROCARP SPECIES UNDER ELEVATED ATMOSPHERIC CARBON DIOXIDE

Mon, 10 Feb 2025 00:00:00 +0000

The consequences of rising atmospheric carbon dioxide (CO₂) level on belowground communities in tropical rainforests continues to be a subject of debate. The main objective of this study was to investigate the distribution of ectomycorrhizal (ECM) fungi and relationship between soil nutrients availability under two different CO₂ concentrations. Free Air Carbon Dioxide Enrichment (FACE) hexagon plot was designed to monitor the impact of CO₂ in tropical rainforest ecosystems at Tekam Forest Reserve, Pahang, Malaysia. Twelve roots and soil samples were collected from two dipterocarp saplings (Shorea lepidota and S. leprosula) in both elevated CO₂ (FACE plot) and control plot conditions. Five soil properties: nitrogen (N), phosphorus (P), potassium (K), carbon (C), and the C:N ratio were analysed. In terms of species distribution, only four species of ECM were found in the FACE plot as opposed to five in the control plot. Unlike Geastrum sp. which was observed in the control plot, Lactarius sp., Russula sp., Tomentella sp., and Cenococcum sp. exist in both control and FACE plots, indicating their adaptability to varying soil nutrient and CO₂ conditions. Then the Detrended Correspondence Analysis (DCA), Principal Component Analysis (PCA), and Canonical Correspondence Analysis (CCA) were employed to establish the relationship between ECM fungi and their host plant, soil nutrient composition and host plant, and combining all parameters, respectively. Shorea lepidota displayed a tendency towards phosphorus in the control plot while S. leprosula showed a preference for higher carbon contents. Tomentella sp. and Cenococcum sp. showed strong association with nitrogen and potassium contents, respectively. Whilst, both Lactarius sp. and Russula sp. were highly associated with C:N ratio. Conclusively, our findings emphasize the need to understand the complex relationship between soil nutrient availability, ECM distribution and elevated atmospheric CO₂ in tropical rainforest ecosystems.

GENETIC VARIABILITY AND HERITABILITY IN GROWTH AND LEAF ASSOCIATED TRAITS OF SELECTED DALBERGIA SISSOO GENOTYPES

Balkrishna T, Ashwani T, Himani S, Taruna — Mon, 10 Feb 2025 00:00:00 +0000

Dalbergia sissoo Roxb. Ex. DC. is a multipurpose, high-value timber tree species native to the Indian subcontinent. The present study aimed at accessing variability among selected 12 genotypes of D. sissoo from Himachal Pradesh and Jammu and Kashmir, India. Branch cuttings from the genotypes were grown under nursery conditions and various plant growth traits like plant height, collar diameter, number of branches per plant, and leaf associated traits such as rachis length, petiole length, leaflet length, length of mid-rib, leaflet width and distance between leaflets, were recorded at six months of age. The genotype DSHH1 (D. sissoo, HFRI, Himachal Pradesh 1) showed better leaf characters viz., rachis length, leaflet length, midrib length and leaf width. However, DSHJ4 (D. sissoo, HFRI, Jammu and Kashmir 4) performed better for collar diameter and the number of branches per plant. A higher Phenotypic Coefficient of Variance (PCV) value than the Genotypic Coefficient of Variance (GCV) for most of the studied traits, with lesser differences between both parameters, indicated that the selected traits were not much under environmental influence. High heritability was recorded for rachis length 68%, the number of branches per plant 75.96%, length of midrib 79.08%, and leaflet length 82.09%. However, moderate heritability was recorded for collar diameter 46.91% and plant height 58.21%. Based on the studied traits, shisham genotypes were grouped into two major clusters. Cluster A was comprised of seven genotypes (DSHH1, DSHJ4, DSHJ1, DSHH4, DSHH5, DSHJ6 and DSHH3) and five in Cluster B (DSHH6, DSHH2, DSHJ5, DSHJ3 and DSHJ2). Thus, there is significant variability in the selected shisham genotypes and they can be utilised for breeding and improvement in traits with better genetic estimates.

SPECIES RICHNESS, DIVERSITY, DENSITY, AND SPATIAL DISTRIBUTION OF SOIL SEED BANKS IN THE MOREMI GAME RESERVE RIPARIAN WOODLANDS OF THE OKAVANGO DELTA, NORTHERN BOTSWANA

Mmusi M, Tsheboeng G, Teketay D, Kashe K, Madome J, Murray-Hudson M — Mon, 10 Feb 2025 00:00:00 +0000

This study aimed to investigate the soil seed banks in the Moremi Game Reserve Riparian Woodlands (MGRWs) of the Okavango Delta, northern Botswana, from March 2019 to June 2019. We examined species richness and diversity, determined densities, assessed the spatial distribution of seeds in the soil, and compared the similarity in species composition between the standing vegetation and soil seed bank flora. A total of 124 plant species were identified in the litter and top 9 cm soil layers with a mean density of 1933 seeds m^-2. Herbs, grasses, sedges, and woody plants were represented by 69, 25, 17, and 13 species, respectively, in 33 families and 92 genera. The overall H' diversity and evenness of the soil seed bank in the MGRWs were 3.7 and 0.77, respectively. The results revealed that Poaceae, Cyperaceae and Asteraceae are the most dominant families in all the germinated species. Four plant communities, namely Kohautia virgata-Ammania baccifera, Bidens pilosa-Urochloa mosambisensis, Setaria verticillata-Brachiaria deflexa, and Cynodon dactylon-Cyperus longus were identified from the soil seed bank. Bray-Curtis ordination showed that there was an overlap between these communities in terms of seed bank composition. However, MRPP analysis showed that there was significant (P < 0.05) separation between germinated soil seed bank communities. The overall spatial horizontal distribution of seeds varied among sampling quadrats while the vertical distribution of seeds exhibited the highest densities occurring in the upper 3 cm of the soil and gradually decreasing densities with increasing depth.

STAND STRUCTURE, SPECIES COMPOSITION AND CARBON ACCUMULATION IN THE POLYHALINE ZONE OF THE SUNDARBANS MANGROVE FOREST, BANGLADESH.

Anjum S, Hossen N, Islam T, Kamruzzaman M — Mon, 10 Feb 2025 00:00:00 +0000

Mangrove stand structure may have direct impact on the conditions and functioning of mangrove ecosystems, and it can modify the distribution and richness of fauna in these habitats. The mangrove ecosystem throughout the polyhaline zone of Sundarbans Mangrove Forest (SMF) was chosen for research on stand structure, biomass accumulation, and carbon storage. Field data were collected from seven sample plots measuring an area of 700 m². Species diversity, diameter class distribution vs. biomass carbon, and species-specific contributions to total biomass carbon were examined. Excoecaria agallocha has maintained its dominance (42.4%, relative density) of the stand. The mean above and below-ground biomass carbon stock of the mangrove community was 197.1 and 173.2 Mg ha^-1 yr^-1, respectively. Avicennia officinalis accounted for only 16.7% individually, contributing over 45% to the total biomass carbon while Xylocarpus mekongensis was the second-highest contributor. The majority of the tree’s diameter were around 10–5 cm, but their share of the total above-ground biomass carbon is only 12%. In comparison, a significant amount of biomass carbon is contributed by tree species with a diameter of 35 to 40 cm, which account for only 3.9% of all trees, but account for 17.8% of the total above-ground biomass carbon. Mangrove communities growing in the polyhaline zone of the SMF have significant species diversity and considerable carbon stock. These findings should be incorporated in future decision-making processes for the area and contribute to a better understanding of the SMF’s function in reducing the effects of global warming.