BIOTROPIA - The Southeast Asian Journal of Tropical Biology
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ABIOTIC FACTORS INFLUENCING MANTANGAN (Merremia peltata) INVASION IN BUKIT BARISAN SELATAN NATIONAL PARK
No full textSome areas in Bukit Barisan Selatan National Park have serious environmental problems related to the invasion of Merremia peltata (Family: Convolvulaceae). This study investigated abiotic factors influencing the invasion. The research compared abiotic conditions in three forest locations with different invasion levels: severe, moderate, and mild. Measured abiotic factors included percentage of tree canopy cover, microclimate variables (temperature and humidity), elevation above sea level, and the physical and chemical properties of the soil surface. In this study, canopy cover was categorized as an abiotic factor because it affects the amount of light reaching the forest floor. A post-hoc Duncan\u27s Multiple Range Test (DMRT) was performed to determine significant differences (p < 0.05) among abiotic variables. Additionally, correlation analysis and multiple linear regression were conducted to evaluate the relationships between abiotic factors and the level of M. peltata invasion. Multiple regression analysis showed that canopy cover significantly (p < 0.05) affected the invasion. Based on the generated model, a 1% increase in canopy cover would decrease the M. peltata invasion by approximately 2.8%. Soil nutrient analysis through multiple linear regression revealed that the C/N ratio, and concentrations of P₂O₅, Ca, Mg, and Na significantly (p < 0.05) influenced invasion level. An increase in C/N ratio and concentrations of P₂O₅ and Ca were correlated with a reduction in invasion, whereas increases in Mg and Na concentrations were associated with higher invasion levels. Overall, the invasion of Merremia peltata in Bukit Barisan Selatan National Park was influenced by an open forest canopy and was associated with high concentrations of Na and Mg in the soil of invaded areas
POTENTIAL OF MANGROVE SEEDLINGS FOR UTILIZATION IN THE MAINTENANCE OF ENVIRONMENTAL QUALITY WITHIN SILVOFISHERY PONDS
Get PDFSilvofishery system has been applied to aquaculture activities and it has been developed in the coastal area of Semarang City, Indonesia. However, information on the initial development of silvofishery ponds concerning the functionality of mangrove seedlings on environmental quality of fish ponds had not been studied. This experiment aimed to determine the environmental conditions of silvofishery ponds and to analyze the effect of seedling stands of mangrove on environmental quality control. The presence of mangrove seedlings caused the decrease of temperature and the increase of salinity. ANOVA showed that mangrove species significantly affected water salinity, while canal width and mangrove species significantly affected turbidity and pH. Regression analysis showed that the height of Rhizophora mucronata had partially significant effect on Total Suspended Solids (TSS), Organic Matter (OM), as well as Nitrogen (N) and Phosphorus (P) concentrations. Diameter of R. mucronata affected temperature. The height and diameter of Avicennia marina affected Dissolved Oxygen (DO). Mixed populations of A. marina and R. mucronata had an effect on water turbidity, while population of only A. marina had a partial effect on water salinity. R. mucronata seedlings had dominant effect on the environmental quality. Mangrove seedlings can be used as environmental quality control within silvofishery ponds to maintain optimal conditions for fish growth. The application of silvofishery in early stage of mangrove seedlings should consider the more abundant plantation of R. mucronata compared to A. marina
INTRASPECIFIC VARIATION ON EARLY GROWTH OF Neolamarckia cadamba Miq. IN PROVENANCE–PROGENY TESTS IN WEST JAVA PROVINCE, INDONESIA
Get PDFGenetic parameters for early growth of Neolamarckia cadamba, an indigenous species with potential as a source of timber wood, were estimated in open-pollinated provenance–progeny tests conducted at two sites in West Java Province, Indonesia. The experiment was arranged in a randomized complete block design with 12 provenances, 105 families, and five replications in four-tree row plots. Total height and root collar diameter were measured at 18 months of age. Significant differences among provenances and among families within provenances were observed for height and collar diameter at all sites, except for collar diameter among provenances at the Parungpanjang site. In general, the Garut (GSJ) provenance performed better than the Kualakencana (KKP) and Nusa Kambangan (NKJ) provenances at both sites. Evaluation of variance components at the two sites showed that the provenance effects (ranging from 0.5 to 1.7%) contributed more to the total variance than family-within-provenance effects (ranging from 0.4 to 0.6%). Genetic correlations between height and collar diameter were weak to moderate. Heritability estimates were low for all traits at Limbangan, whereas they were moderate at Parungpanjang. Estimated genetic gain for height and diameter based on proportional family selection of 0.30 was 0.13 and 0.18 at Limbangan, and 0.31 and 0.16 at Parungpanjang, respectively. Continued heritability measurement is required to obtain stable values. Stable heritability combined with family selection and within-family selection will improve genetic gain
DIVERSITY OF ACTINOMYCETES FROM EKA KARYA BOTANICAL GARDEN, BALI
Get PDFA total of 29 actinomycetes strains were isolated and identified by full sequence analysis of the 16S rRNA gene. Samples were collected from Bali Island, Indonesia, including 18 soil and 20 leaf litter samples from Eka Karya Botanical Garden. Two isolation methods were used in this study: SDS-extract (SY) and Rehydration-Centrifugation (RC). Based on 16S rRNA gene analysis, the isolated actinomycetes were grouped into two genera. Molecular analysis of 16S rRNA gene similarities showed that the actinomycetes isolated from Eka Karya Botanical Garden were of diverse origin. Analysis of soil samples resulted in 144 isolates belonging to 24 genera and more than 87 species, with Streptomyces being the dominant genus. This was followed by Actinoplanes (25 isolates, 17%). From leaf litter samples, 85 isolates were obtained, belonging to 9 genera and more than 41 species. The most dominant genus was Catenuloplanes (42 isolates, 49%), followed by Actinoplanes (16 isolates, 19%)
SOIL SEED BANK OF AN EXOTIC Acacia sp. PLANTATION AND AN ADJACENT TROPICAL HEATH FOREST IN BRUNEI DARUSSALAM
No full textAcacias are among the most successful invasive plants in tropical regions, causing significant negative impacts on biodiversity and ecosystem services of invaded habitats. Their invasiveness is partly attributed to their ability to accumulate large soil seed banks in areas they colonize. This study compared seedling emergence and soil seed bank composition under an Acacia mangium plantation and an adjacent tropical heath (kerangas) forest in the Andulau Forest Reserve, Brunei Darussalam. Soil samples were collected from ten 20 × 20 m plots established in three contrasting habitats: the plantation, the adjacent heath forest, and the transition zone between them. Soil samples were subjected to smoke and heat treatments, and seedling emergence was monitored daily over a 12-week period. In a parallel assessment, variations in species richness, seed density, and seed viability were examined across the ten plots. Seedling emergence was highest in the plantation and lowest in the heath forest plots. However, no significant differences among treatments and no significant treatment–habitat interactions were detected. Species richness, seed density, and seed viability in the plantation plots were significantly lower than those in the transition zone and intact heath forest plots. Acacia mangium seeds were not detected in the heath forest soil seed banks but were found in plantation and transition zone plots. The lower native plant species richness, seed density, and viability in the plantation may indicate a higher regeneration potential for the heath forest habitat should major disturbance occur within the reserve. Proper plantation management and continuous monitoring of soil seed banks are recommended to minimize the spread of invasive Acacia species into tropical heath forests of Borneo
BIOMASS AND CARBON STOCK ESTIMATION INVENTORY OF INDONESIAN BANANAS (Musa spp.) AND ITS POTENTIAL ROLE FOR LAND REHABILITATION
No full textBananas (Musa spp.) are widely cultivated in Indonesia. They are commonly grown in backyards, home gardens, intercropped with short-term crops, and in agroforestry systems. The potential of bananas to sequester carbon has been reported, but information on performance variation among cultivars remains limited. An inventory of biomass and carbon stock (C-stock) estimation was conducted on banana accessions in the Musa germplasm collection of Purwodadi Botanic Garden, Pasuruan. Biomass and C-stock estimations were carried out for 42 individual banana accessions consisting of five wild species and 37 cultivars using a non-destructive allometric equation method for banana. The objectives of this study were to estimate the biomass and C-stock of Indonesian bananas in the Purwodadi germplasm collection, to project time-average above-ground C-stock of banana-based farming systems in Indonesia, and to discuss the role of bananas in landscape rehabilitation. The results showed that biomass and C-stock values varied among accessions. Wild banana species Musa balbisiana had higher biomass and C-stock compared to Musa acuminata. Cultivars containing one or two “B” genomes (ABB and AAB) were more vigorous and contributed higher biomass and C-stock than AAA and AA cultivars. Among the cultivars, the highest C-stock contribution was recorded in Pisang Kepok Bung (average 6.92 kg C/plant), while the lowest was found in Pisang Rayap (average 0.67 kg C/plant). On average, the Indonesian bananas examined contributed approximately 2.26 kg C/plant or 0.98 tonnes C/ha. The total banana growing area increased from 73,539 ha in 2000 to 101,822 ha in 2010 and slightly decreased to 100,600 ha in 2014. These areas contributed an estimated C-stock of 72.28 tonnes (2000), increasing to 100.07 tonnes (2010), followed by a slight decline to 98.97 tonnes in 2014—values based only on recorded cultivation areas. Banana plants—especially when combined with woody tree crops—have potential as key components of agroforestry and mixed farming systems, home gardens, and landscape rehabilitation, contributing to carbon reduction and providing economic benefits for surrounding communities
EFFECT OF SUBSTRATE MOISTURE CONTENT AND INVASIVE GRASS COMPETITION ON NATIVE FIG (Ficus fistulosa) SEEDLING RECRUITMENT IN LIMESTONE QUARRIES
No full textThis study was conducted to assess the potential use of the native fig (Ficus fistulosa) for rehabilitating degraded habitats in limestone quarry areas. A greenhouse experiment was performed to evaluate the effects of different substrate moisture levels and competition between the native fig (Ficus fistulosa) and the invasive grass Pennisetum polystachyon on the growth and survival of the native fig. Ficus fistulosa was selected as the study species because it exhibited the highest Importance Value Index (IVI) among other fig species recorded in the Ciampea limestone hill. The results showed that substrate moisture levels did not significantly affect fig biomass, and invasive grass biomass was not reduced under drought stress. However, the interaction between substrate moisture levels and competition with the invasive grass significantly reduced overall fig biomass, although it did not affect leaf number or individual plant size. This study suggests that successful quarry rehabilitation efforts should include invasive species management alongside soil treatment interventions
CELLULASE PRODUCTION BY Bacillus subtilis M1 USING PRETREATED GROUNDNUT SHELL–BASED LIQUID STATE FERMENTATION
No full textGroundnut shell, which is rich in natural cellulose, was assessed as a substrate for the production of cellulase enzyme by cellulolytic bacteria. In the present investigation, the bacterial isolate M1 was found to be capable of producing high amounts of endoglucanase and exoglucanase on alkali-treated groundnut shell. The effects of various nitrogen sources, amino acids, and Ca²⁺ ions in the medium containing pretreated groundnut shell were also evaluated. It was observed that a 2% substrate concentration and 1 mM calcium concentration were optimal for cellulase production. Among the nitrogen sources tested, ammonium nitrate was found to be the most effective. Asparagine, tryptophan, and methionine were found to stimulate cellulase activity
BIOLOGICAL REMEDIATION OF CYANIDE: A REVIEW
Get PDFCyanide and its complexes are produced worldwide as industrial waste or effluents. Biodegradation is considered the most economical and effective method for removing cyanide from the environment. Numerous studies have identified various microorganisms capable of degrading cyanide under natural conditions. Hydrolytic, oxidative, reductive, and substitutive/transfer reactions are among the most common pathways utilized by microorganisms during cyanide degradation. Biodegradation may occur under aerobic or anaerobic conditions, depending on environmental factors. The use of immobilized microorganisms or purified enzymes has also been shown to increase degradation efficiency. Several microbial species, including Klebsiella oxytoca, Corynebacterium nitrophilum, Brevibacterium nitrophilum, Bacillus spp., Pseudomonas spp., Rhodococcus spp., and strain UKMP-5M, have been reported to be highly effective in cyanide biodegradation
ICHTYOFAUNA AT CIJALU RIVER, CILACAP REGENCY, CENTRAL JAVA PROVINCE, INDONESIA
Get PDFCijalu River is located in the western part of Cilacap Regency, Central Java Province. The river flows through forestry, housing, and farming areas. These conditions lead to the prediction that its physico-chemical characteristics may have been altered, potentially affecting the fish species inhabiting the river. This study aimed to collect data on fish species inhabiting the Cijalu River and analyze their distribution. A survey method was conducted using a clustered random sampling technique. The river was divided into three sections: upstream, midstream, and downstream. Species diversity was measured based on the number of species recorded, while distribution was determined by the presence of fish species in each sampling site. Nineteen fish species belonging to ten families were identified from the Cijalu River. The ten families recorded were Anabantidae, Bagridae, Balitoridae, Channidae, Cichlidae, Cyprinidae, Loricariidae, Osphronemidae, Poecilidae, and Sisoridae. Cyprinidae represented the family with the highest number of species (6 species), followed by Channidae (3 species), Bagridae (2 species), and Osphronemidae (2 species). The remaining families were each represented by one species. Different patterns of fish distribution were observed during the study. Glyptothorax platypogon and Channa gachua were found only in the upstream area, while Anabas testudineus was collected only from the downstream section. Other species were found either from the midstream to downstream areas or throughout the entire river system. The variation in species distribution may be associated with changes in physico-chemical characteristics from upstream to downstream, particularly substrate type and water velocity