Buitenzorg: Journal of Tropical Science

Evaluating the Driving Forces Behind Urban Land Transition in a Coastal Region: Integration of Geospatial and Local Knowledge Approach

2026-06-30T03:29:51+00:00

Agricultural land transition in rapidly urbanizing coastal regions poses significant challenges for sustainable land use planning and long-term food security. This study examines the driving forces behind agricultural land conversion in Cilegon City, Banten Province, Indonesia as one of Southeast Asia's most industrialized coastal cities by integrating Remote Sensing (RS), Geographic Information Systems (GIS), and the Analytical Hierarchy Process (AHP) with structured local knowledge elicitation. Land cover classification was performed using Random Forest machine learning applied to multi-temporal Landsat imagery (2011 and 2023), revealing substantial encroachment of non-agricultural land uses. Through pairwise comparison interviews with six domain experts, AHP weighting assigned the highest influence to rainfall (18%), soil quality (15%), and road accessibility (14%) as transition drivers. The resulting transitional suitability map, validated against observed land cover change, achieved an overall accuracy of 88.70% and a Kappa coefficient of 0.86, demonstrating the model's strong predictive capacity. The findings underscore that environmental, infrastructural, and socio-economic factors collectively govern land conversion dynamics. This study contributes a replicable, participatory spatial framework that bridges objective geospatial data with community-embedded knowledge, supporting more inclusive, evidence-based urban planning and agricultural land management in fast-growing coastal cities.

Keywords: analytical hierarchy process, coastal city, land use change, local knowledge, remote sensing.

Comparative Evaluation of ITS1, ITS2, and LEAFY (LFY) CDS Markers for Species Discrimination in Asteraceae

2026-06-30T03:29:48+00:00

Asteraceae is one of the largest and most diverse angiosperm families, making species identification challenging, especially among closely related taxa with overlapping morphological characters. This study evaluated the performance of ITS1, ITS2, and the coding sequence of the LEAFY (LFY) gene as molecular markers for discriminating selected Asteraceae species and assessing relationships at the genus, tribe, and subfamily levels. Publicly available sequences were retrieved from NCBI databases and curated based on taxonomic identity, marker annotation, sequence quality, and accession consistency. The ITS1, ITS2, and LFY coding sequence (CDS) datasets were aligned separately using MUSCLE in MEGA, followed by sequence variation analysis, Maximum Likelihood phylogenetic reconstruction, and pairwise genetic distance analysis. All three markers recovered broad taxonomic patterns, including the clustering of Chrysanthemum species and the separation of more distant genera such as Helianthus, Tagetes, Erigeron, Cynara, and Lactuca. LFY CDS showed the highest absolute number of variable sites and parsimony-informative sites, followed by ITS2 and ITS1. ITS2 provided slightly greater phylogenetic information than ITS1, while LFY CDS provided an independent nuclear coding signal that complemented the ribosomal ITS markers. Overall, each marker contributed useful phylogenetic information for assessing taxonomic relationships within Asteraceae.

Keywords: Asteraceae, ITS1, ITS2, LFY, DNA barcoding, species discrimination, phylogenetic analysis.

Interannual Rainfall Variability and Its Impacts on Cropping Patterns in Malang Regency, Indonesia

2026-06-30T03:29:53+00:00

El Niño and La Niña events typically affect rainfall patterns and water availability for plants, especially in rainfed and upland farming systems. This study examines year-to-year variations in rainfall associated with El Niño and La Niña events, as well as their impacts on potential planting seasons and the management of food crop planting patterns in Malang Regency. The rainfall data used in this analysis are from the Karangploso and Karangkates climatology stations for the period 2012-2024. The analysis reveals that over the past 13 years, El Niño events have not shifted the duration of the dry or rainy seasons in Lawang Subdistrict, nor have they reduced the rainy-season duration by 1 decade compared to normal conditions in Donomulyo Subdistrict. However, La Niña events can prolong the rainy season by 3-13 decades in Lawang Subdistrict or 2-14 decades in Donomulyo Subdistrict. The average potential planting time at the research location is 210 days in Lawang Subdistrict and 240 days in Donomulyo Subdistrict, posing a significant risk of planting rice across two growing seasons. By selecting adaptive crops and managing planting patterns, it could be possible to plant three times using a rice-corn-beans pattern during the planting seasons in the Lawang Subdistrict or a rice-corn and rice-beans pattern in the Donomulyo Subdistrict. During La Niña events, crop pattern management can be more flexible, and planting intensity can be increased by 3-4 times through effective crop pattern management.

Microalgae-Based Fertilizers: Functions, Applications, and Market Prospects in Organic Farming

2026-06-30T03:29:58+00:00

Microalgae exhibit high biodiversity and are found in various habitats, including agricultural soil. The intensification of agriculture by chemical fertilizers results in significant environmental problems, including water pollution, accumulation of xenobiotic chemicals, diminished soil quality and fertility, and adverse effects on human health. Organic farming is highlighted as an effective approach to mitigate these problems. Microalgae offer key functions in agriculture as biostimulants, biofertilizers, biocontrol agents, sources of phytohormones, and soil moisturizers. These roles indicated the importance of microalgae in sustainable and organic agriculture, particularly for CO₂ sequestration, nutrient recycling from waste streams, and enhancing crop tolerance to abiotic stress. This review discusses practical application methods, field challenges, sustainable water sources for microalgae biomass production, market trends for biofertilizers made from this biomass, and long-term sustainability factors to establish safety and standardization protocols to ensure their reliability. Microalgae biomass can be produced in photobioreactors or open ponds and applied to agricultural land as wet inoculum, dry biomass, or extracted metabolites. Integration with irrigation and hydroponic systems offers additional potential for efficient nutrient delivery. The global market for microalgae fertilizer is projected to expand significantly due to increasing awareness of sustainable farming and rising demand for organic food. These fertilizers are eco-friendly, reduce nutrient waste and soil degradation, and are suitable for organic crop production as they are natural and free from synthetic chemicals or GMOs. In conclusion, microalgae represent sustainable and effective strategies to enhance soil fertility, stimulate plant growth, and strengthen crop protection in organic farming.

Keywords: biocontrol agents, algal biomass, circular bioeconomy, commercial viability, abiotic stress mitigation

Genetic Diversity and Development of Molecular Marker Toolkit for Early Detection of Seedlings Based on Early Maturity of Sugar Palm (Arenga pinnata Merr.) in Indonesia: A Review

2026-06-30T03:29:55+00:00

Sugar palm (Arenga pinnata Merr.) is a promising estate crop with significant potential as a raw material for palm sugar, starch, fiber, and bioethanol production. However, its utilization and cultivation in Indonesia have not been fully optimized. This plant is found throughout Indonesia's tropical rainforests, from Sumatera to Papua. While several genetic diversity studies of sugar palm in Indonesia have been conducted using morphological traits, isozymes, and molecular markers, these efforts are less extensive than those focused on other members of the Arecaceae family. To date, the genetic diversity studies of sugar palm in Indonesia are still limited in terms of the number of markers, population coverage, and the use of modern genomic approaches. This paper aims to review the current status of genetic diversity research on sugar palm in Indonesia and the development of a molecular marker toolkit for the early identification of early maturing sugar palm seedlings.. The introduction of this toolkit is expected to accelerate sugar palm breeding programs in Indonesia, particularly in developing improved varieties that can benefit farmers. Further dissemination and broader availability of this kit are necessary to increase recognition of its benefits and facilitate its widespread adoption within the community.

Keywords: detection toolkit, genetic diversity, molecular marker, plant breeding, estate crop