IRAWAN WIJAYA KUSUMA
Faculty of Forestry, Universitas Mulawarman. Jl. Penajam, Gunung Kelua, Samarinda 75123, East Kalimantan, Indonesia

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Short Communication: Diversity of plant species growing during fallow period of shifting cultivation and potential of its biomass for sustainable energy production in Mahakam Ulu, East Kalimantan, Indonesia YULIANSYAH; MUHAMMAD TAUFIQ HAQIQI; ELIS SEPTIA; DEWI MUJIASIH; HELMI ALFATH SEPTIANA; KRISNA ADIB SETIAWAN; BUDHI SETIYONO; EDDY MANGOPO ANGI; SAPARWADI; NUR MAULIDA SARI; IRAWAN WIJAYA KUSUMA; RUJEHAN; WIWIN SUWINARTI; RUDIANTO AMIRTA
Biodiversitas Journal of Biological Diversity Vol. 20 No. 8 (2019)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d200818

Abstract

Abstract. Yuliansyah, Haqiqi MT, Septia E, Mujiasih D, Septiana HA, Setiawan KA, Setiyono B, Angi EM, Saparwadi, Sari NM, Kusuma IW, Rujehan, Suwinarti W, Amirta R. 2019. Short Communication: Diversity of plant species growing during fallow period of shifting cultivation and potential of its biomass for sustainable energy production in Mahakam Ulu, East Kalimantan, Indonesia. Biodiversitas 20: 2236-2242. Fallow period is a time gap, as long as 15 years, for improving natural soil fertility of land used for traditional shifting cultivation, in the tropical areas commonly used by Dayak People in Borneo Island. During this period, many biomass plant species naturally grow and develop a new forest vegetation community with shrub and medium trees, dominated by fast-growing pioneer species. In this study, we investigated the plant diversity in fallowed shifting cultivation area in Batu Majang Village, Mahakam Ulu District, East Kalimantan Province, followed by analysis of the suitability of wood characteristics for energy production. We classified the study area according to the age of fallow period as: 1-3 years, 4-6 years, 7-9 years and 10-15 years. We found 29 species among which 13 were identified as the top species according to the highest value for important value index. Potential wood biomass production increased from 3.01 m3 ha-1 to 399.62 m3 ha-1. V. pinnata and M. pearsonii showed the highest dominance which is present in almost all area based on age classification groups. Wood from V. pinnata achieved the highest calorific valueof18.00 MJ kg-1 whereas N. cadamba and M. sericea were in the second and third places with the value of 17.30 MJ kg-1 and 17.28 MJ kg-1, respectively. Therefore, V. pinnata was an important species among all other species observed because of high adaptability and high energy content. In addition, possible energy production at the end of the fallow period of 15 years was 2.92 GJ ha-1.
Potential antibacterial and antioxidant activities of ten essential oils from East Kalimantan, Indonesia FARIDA ARYANI; IRAWAN WIJAYA KUSUMA; YENNY MELIANA; NUR MAULIDA SARI; HARLINDA KUSPRADINI
Biodiversitas Journal of Biological Diversity Vol. 24 No. 1 (2023)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d240175

Abstract

Abstract. Aryani F, Kusuma IW, Meliana Y, Sari NM, Kuspradini H. 2023. Potential antibacterial and antioxidant activities of ten essential oils from East Kalimantan, Indonesia. Biodiversitas 24: 665-672. This study aimed to evaluate ten aromatic essential oils' antibacterial and antioxidant activity. Ten aromatic herbs were distilled using the water and steam distillation method. The essential oils obtained was tested for its physical properties, color, refractive index, and specific gravity. The refractive index was measured using a refractometer. On the other hand, specific gravity was measured using a pycnometer. Antioxidant activity testing using the free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) and ascorbic acid was used as the control. Antibacterial activity testing using the agar diffusion method and pathogenic bacteria, namely Salmonella typhi, Escherichia coli, Propionibacterium acnes, and Staphylococcus aureus. Chloramphenicol was used as a positive control and acetone as a negative control. The results obtained essential oils with a slightly yellowish to brownish-yellow color. The highest refractive index and specific gravities were Syzygium aromaticum oil, and the smallest was Litsea elliptica and Eucalyptus pellita oils. The results of the antioxidant activity test carried out at a concentration of 500 µg/mL range from 4.82 % to 85.06 % inhibition and showed that the highest inhibition was Cymbopogon citratus and Syzygium aromaticum by 55.76 % and 85.06%, respectively. Antibacterial activity of ten essential oils showed a varied inhibition zone (0-60 mm) against S. typhi, E. coli, P. acnes, and S. aureus. The oil from Cymbopogon citratus and Citrus hystrix had the highest activity against S. typhi (60 and 21.67 mm, respectively), E. coli (60 and 20.33 mm, respectively), P. acnes (60 and 31.11 mm, respectively) and S. aureus (60 mm and 17.89 mm, respectively). The research results showed that the essential oils in this study had the potency for development as a natural antibacterial and antioxidants agents.