Buitenzorg: Journal of Tropical Science

Vegetation diversity in mangrove forest area of mojo village, Ulujami district, Pemalang regency, Central Java

Aisyah Fajar Kartika — 2024-12-30

Mangrove forests are vital for coastal protection, biodiversity, and local livelihoods but face significant threats such as erosion, land-use changes, sedimentation, and waste pollution. This study assessed the diversity, dominance, and evenness of the mangrove ecosystem in Mojo Village, Ulujami District, Pemalang Regency, an area impacted by coastal abrasion. The research, conducted from August to September 2023, used purposive sampling with quadrant transects at four stations. Three plot sizes (10 m × 10 m, 5 m × 5 m, and 2 m × 2 m) were employed to analyze different mangrove growth stages (tree, sapling, and seedling). The mangrove diversity index ranged from 0 to 1.232, with the highest value observed in the tree stage (1.232) and the lowest in the seedling stage (0). The species Avicennia alba exhibited the highest dominance across all stages. The evenness index varied between 0 and 0.95209, indicating high evenness in trees and saplings, while the seedling stage exhibited low evenness. Water quality parameters were found to be supportive of mangrove growth. They included temperature (28.8–30.5°C), salinity (25–30 ppt), pH (5.90–6.21), and dissolved oxygen (5.5–14.9 mg/l). The results highlighted variations in diversity and evenness across the mangrove ecosystem's growth stages. The findings provide valuable insights into the current state of mangroves in the area and underscore the urgent need for continued monitoring and sustainable management to restore and conserve the mangrove forests in Mojo Village.

Keywords: mangrove vegetation diversity, Mojo village, Ulujami

Enhancing the quality of Kasgot biofertilizer using Pichia cecembensis UNJCC Y-157 and amino acids to boost mustard greens (Brassica juncea L.) growth

Riska Ariskaa — 2024-12-30

Mustard greens (Brassica juncea L.) is a crop with relatively high productivity due to its abundant soil nutritional content. Soil fertility enhancement is commonly achieved through fertilization. Kasgot fertilizer, a biofertilizer derived from the residue of black soldier fly (BSF, Hermetia illucens) larvae that consume fermented feed, serves as an eco-friendly option beneficial for plant growth. This organic waste is fermented with microorganisms, specifically the yeast Pichia cecembensis UNJCC Y-157, provided by the Jakarta State University, along with added amino acids. This study aimed to determine the effects of P. cecembensis UNJCC Y-157 yeast and amino acids on BSF larval growth and to assess the impact of the resulting kasgot fertilizer on mustard greens growth. This research used a completely randomized design (CRD) with three treatments, including one control, with five replications on fermented BSF larvae feed. For the application of kasgot fertilizer on mustard greens, four treatments with four replications were applied, with data analyzed using one-way analysis of variance (ANOVA). The results indicated that BSF larvae fed with added P. cecembensis UNJCC Y-157 yeast and amino acids had superior wet weight, observed through morphological characteristics. Additionally, in terms of mustard greens growth, parameters such as plant height, leaf count, leaf width, leaf length, and fresh weight showed that kasgot fertilizer containing P. cecembensis UNJCC Y-157 yeast yielded better than morphological outcomes in the plants.

Keywords: Pichia cecembensis, fermented feed, black soldier fly, Brassica juncea L., amino acids

Surface tension and in vitro tyrosinase inhibitory activity of tamanu oil (Calophyllum inophyllum L.)

Anggi Kusnaedi — 2024-12-30

Tamanu or nyamplung oil, derived from Calophyllum inophyllum L., is commonly used in traditional medicine and occasionally used as a moisturizer in skincare cosmetics. In silico predictions suggested that tamanu oil contained compounds capable of inhibiting tyrosinase activity. This study aimed to measure the surface tension of tamanu oil and evaluate its tyrosinase inhibitory activity in vitro. The surface tension of tamanu oil was measured using the du-Nouy ring method with a tensiometer, while tyrosinase inhibitory activity was assessed by spectrophotometry using a microplate reader. The study revealed that the surface tension of tamanu oil was measured at 41.83±0.76 mN/m, and the tyrosinase inhibitory activity of tamanu oil was determined to be 83.75±0.41%. Notably, the inhibitory activity of tamanu oil was comparable to that of the positive control, kojic acid, which exhibited a tyrosinase inhibition of 84.59±2.04%. We concluded that tamanu oil has potential as a natural surfactant raw material and may serve as an effective tyrosinase inhibitor.

Keywords: Calophyllum inophyllum L., nyamplung, surface tension, tamanu oil, tyrosinase inhibitor

A comparative study of DNA barcoding markers for Bamboo

Seli Rizqi Awaliah — 2024-12-30

The Bambusoideae subfamily, a significant group within the Poaceae family, contains diverse genera with complex taxonomic relationships. This study aimed to elucidate the phylogenetic relationships and genetic diversity within the bamboo, focusing on the utility of DNA barcoding markers, i.e., ITS2, matK, and rbcL, in bamboo species identification. By analyzing sequence data from these markers, phylogenetic trees were constructed using the maximum likelihood method to infer evolutionary relationships among species. The results showed that ITS provides the highest resolution for species-level identification, distinguishing closely related species more effectively than matK and rbcL. While matK demonstrated robust genus-level classification, rbcL was limited by its high conservation, making it more suitable for broader taxonomic groupings. These findings contribute to a better understanding of bamboo taxonomy and highlight the importance of marker selection based on the taxonomic resolution required. The study also emphasizes the complementary use of these markers to provide a comprehensive view of bamboo phylogenetics.

Keywords: bamboo taxonomy, DNA barcoding, ITS2, matK, rbcL

Land suitability evaluation for sugarcane cultivation based on agroecological zoning system in East Java Indonesia

Riska Ayu Purnamasari — 2024-12-30

Agroecological zoning system is essential to accelerate the production of plantation crops such as sugarcane. This is a tool that helps to identify the most suitable areas for growing specific crops based on the physical and biological characteristics of the land. The ideal conditions for sugarcane growth can be achieved from optimal planting land conditions and adequate climate and fertilization. Land use planning is key to the sustainability of plantation crops in Indonesia. In this study, we used land suitability evaluation for sugarcane cultivation using an agroecological zoning system. Multisource of suitability criteria was used from the thematic map that included the land use/land cover map, slope map, rainfall map, and soil type map as physical and biological characteristics of the land. On the land suitability map for sugarcane cultivation, the results are in the form of land area that was adjusted to the Food and Agriculture Organization indicators regarding land suitability class. We found that 23.20% of the area (11,149.49 km²) was very suitable for sugarcane cultivation, 30.18% (14,499.67 km²) was moderately suitable, 36.05% (17,321.71 km²) was marginally suitable, and 10.55% (5,068.25 km²) was not suitable for sugarcane plantation. In this study, it was found that around 1,114,949 ha of land in East Java had the potential to become sugarcane plantations based on the agroecological zoning system. This research recommended that the integrated approach of Geographic Information Systems (GIS) with satellite remote sensing vegetation datasets utilization might help to develop the site-specific management of sugarcane plantations.

Keywords: agroecological zone, land suitability, mapping, remote sensing, sugarcane.