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.

Jamur makro merupakan salah satu keanekaragaman hayati yang penting di hutan tropis Indonesia. Jamur makro memiliki peran penting dalam siklus biogeokimia tanah, siklus hara, pendekomposer sehingga membantu proses dekomposisi bahan organik dalam ekosistem hutan. Penelitian ini bertujuan untuk identifikasi jamur makro yang tumbuh di kawasan Arboretum Inamberi dan dapat memberikan informasi tentang potensi keanekaragaman yang ada di kawasan tersebut yang diharapkan dapat dimanfaatkan sebagai sumber pangan, obat, dan pendekomposer. Metode pengumpulan jamur makro yang dilakukan adalah dengan menggunakan metode jelajah (Cruise Method) pada bulan Agustus-September 2016. Identifikasi jenis makrofungi dilakukan dengan menggunakan ciri morfologi. Hasil survey menunjukkan terdapat 34 jenis dari 17 famili yang termasuk kedalam 2 divisi makrofungi. cendawan yang banyak ditemukan berasal dari divisi Basidiomikota dengan jumlah spesies sebanyak 31 spesies dan yang paling sedikit dari divisi Askomikota dengan jumlah 3 spesies. Sebagian besar cendawan Basidiomikota yang ditemukan berada pada pohon mati/kayu lapuk dan serasah daun/tanah.