Abstract. Murdjoko A, Jitmau MM, Djitmau DA, Siburian RHS, Ungirwalu A, Wanma AO, Mardiyadi Z, Rumatora A, Mofu WY, Sineri AS, Fatem SM, Worabai D, May NL, Tokede MJ, Warmetan H, Wanggai CB, Wanma JF, Sirami EV, Paembonan JB, Unenor E, Kuswandi R, Lekitoo K, Khayati L, Benu NMH, Tambing J, Saragih ASB. 2020. Heterospecific and conspecific associations of trees in lowland tropical forest of New Guinea. Biodiversitas 21: 4405-4418. The vegetation in the tropical rainforest of New Guinea consists of a large number of species that interact with each other within and among species. While several studies have attempted to reveal the diversity of flora of New Guinea, little is known about plant communities that develop associations. This study aimed to investigate the associations of tree species in lowland tropical forest in New Guinea. The associations depicted in this study were in the form of conspecific associations (among small and large individuals within same species) and heterospecific (among individuals of different species and divided into under and upper story). We established 48 rectangular plots created in Murkim and Teiraplu as part of Pegunungan Bintang Regency, Papua Province. Canonical correspondence analysis (CCA) was used to analyze heterospecific and conspecific associations. The results showed that the understory and upper story vegetation had different patterns of heterospecific association. The understory configured three heterospecific associations, consisting of 5, 13, and 90 species, while the upper story formed four heterospecific associations with 4, 8, 11, and 63 species. The analysis of conspecific associations showed of 149 tree species recorded in the study sites, only 66 species that had both small and large individuals, displaying the pattern of conspecific association. Among them, 41 species had positive associations while 25 species had negative associations. Our findings enrich the knowledge in theoretical ecology of tropical forests, especially in New Guinea.

Trees are significant components of ecosystems built by several widespread species. For instance, Papua forest is known to comprise abiotic and biotic elements. Also, certain plants have grown in popularity to a point where they are discovered almost everywhere. The purpose of this study, therefore, was to investigate tree diversity, distribution, and the importance of conservation. Data were collected in four locations using a total of 24 sample plots spread across Idoor, Karst, Persemaian, and Torembi, where seven, four, seven, and five plots were allocated, respectively. These forests formed a mixed natural plantation comprising 76 species from 35 families. Furthermore, Idoor and Karst generated the highest species diversity and varied significantly compared to Persemaian, while Torembi showed similarities with the other three locations. This condition formed three ecosystem communities across Persemaian, Karst, Idoor, and Torembi. Also, the composition of the dominant species showed variations at the seedling and sapling levels believed to structure the understory, while the pole and tree levels characterized the overstory. The total species status was described as critically endangered (CR) of two species, vulnerable (VU) of six species, least concern (LC) of 28 species, and data deficient (DD) species. Therefore, location management is advised to not only pay significant attention in terms of economic benefits but also ecological, including the provisions for ex-situ and in-situ conservation to support sustainable forest management.

Organic waste of public market is one of the problems that greatly impact public health. The technology of processing public market waste into compost is a very good alternative, yet how long does it take, to process into compost and any nutrient contained requires research on this matter, as well as its application to plants, in this case, agarwood. The method used in this study was the experimental method with the old treatment of compost formation, as well as its application to agarwood plant using a completely randomized design (CRD). The results showed that 28 days of composting contained nutrients in the form of ions which were more easily absorbed by plants compared to nutrient content at duration 7 days. This is supported by the application of compost, where the addition of compost is very influential on the height of agarwood. As such, compost from organic ingredients is very well applied to agarwood plant.

Abstract. Murdjoko A, Djitmau DA, Sirami EV, Siburian RHS, Ungirwalu A, Mardiyadi Z, Wanma JF, Mofu WY, Marwa J, Susanti CME, Tokede MJ, Imburi CS, Sagrim M, Mamboai H, Sonbait LY, Dwiranti F, Salosa YY, Paembonan JB, Wiradyo ET, Unenor E, Benu NMH, Saragih ASB. 2021. Tree species diversity of Pegunungan Bintang, Papua, Indonesia as potency of wood supply. Biodiversitas 22: 5645-5655. The tropical rainforest is a primary global concern in many aspects. Therefore, this study aimed to describe the tree diversity in Pegunungan Bintang Forest, Papua, Indonesia. There are 10 dominant species from seedlings, saplings, poles, and trees, indicating the timber production potency. This study set systematic plots in Murkim and Teiraplu Sub-districts to collect taxonomic information, diameter, and clear bole height samples. The results showed that the forest was categorized as a tropical mixed due to diverse tree species. The leading plant families included Moraceae, Myrtaceae, Euphorbiaceae, Lauraceae, and Anacardiaceae, with various seedlings, saplings, poles, and trees. The potency of timber was reflected through sample distribution using the reverse J-shaped curve, identifying the merchantable trees with larger and smaller diameters as re-established. However, timber utilization management requires silvicultural treatments using selective logging by diameter limit and logging cycle for forest sustainability.

Kota Sorong merupakan salah satu kota di Provinsi Papua Barat yang sering menghadapi masalah banjir. Namun seberapa luas daerah yang rentan terhadap kondisi ini, belum ada data mengenai hal tersebut. Untuk itu perlu dilakukan penelitian untuk mengetahui sebaran tingkat kerentanan bencana banjir di kota Sorong. Penelitian ini merupakan penelitian deskriptif menggunakan analisis dan sebaran pola tingkat kerentanan banjir dengan teknik analisa data menggunakan overlay, scoring, dan layout berdasarkan software Arc View 10.5. Hasil penelitian menunjukkan bahwa tingkat kerentanan banjir di Kota Sorong diklasifikasikan dalam 4 tingkat kerentanan banjir yang meliputi sangat rentan, rentan, kurang rentan, dan tidak rentan. Seluas 4, 53 % wilayah kota Sorong tergolong sangat rentan terhadap banjir, rentan banjir seluas 33,65 % yang kurang rentan sebasar 42.11 % dan daerah tidak rentan sebesar 19,71 %. Wilayah yang harus diwaspadai karena rentan dan sangat rentan banjir adalah seluas 38,18 % meliputi Distrik Sorong Timur, Manoy, Sorong, Sorong Kota dan Sorong Barat. Daerah tersebut adalah pusat pemerintahan dan termasuk daerah padat pemukiman penduduk.