Jurnal Biodjati 5(2):199-213, November 2020 http://journal.uinsgd.ac.id/index.php/biodjati e-ISSN : 2541-4208 p-ISSN : 2548-1606 VEGETATION STRUCTURE, COMPOSITION, AND SOIL PROPERTIES OF DRY LAND ON ISLANDS IN BALIKPAPAN BAY, EAST KALIMANTAN Tri Sayektiningsih 1 *, Bina S. Sitepu 2 , Ishak Yassir 3 , Ulfah K. Sari 4 , Mukhlisi 5 , Amir Ma’ruf 6 INTRODUCTION Kalimantan which is part of Borneo has several small islands, such as Nunukan and those located in Balikpapan Bay, due to the infuence of geological processes in the past (Husein, 2017; Karim et al., 2019). Micro- climate (Chahouki et al., 2012) and soil pro- perties (Hattermann et al., 2018) afect the biophysical condition of the small islands, re- sulting in the diference in vegetation charac- teristics between small islands and the main- Citation Sayektiningsih, T., Sitepu, B. S., Yassir, I., Sari, U. K., Mukhlisi & Ma'ruf, A. (2020). Vegetation Structure, Composition, and Soil Properties of Dry Land on Islands in Balikpapan Bay, East Kalimantan. Jurnal Biodjati, 5(2), 199-213. Received : November 17, 2019 Accepted : September 27, 2020 Abstract. Some small islands in Balikpapan Bay consist of dry land which may have diferent vegetation structure and composition. Our study was the frst to uncover vegetation conditions and soil proper- ties of dry land on small islands in Balikpapan Bay, which has never been conducted before. The research was carried out on Kalawasan and Karantina islands. Information on vegetation was obtained by applying a line transect method. Data on soil properties were col- lected by setting up 3 sampling plots in each transect of vegetation. Parameters used for analysing vegetation including relative densi- ty, relative frequency, relative dominance, Shannon-Wiener diversi- ty index, evenness index, and similarity index. Meanwhile, data on soils were analysed descriptively. Trees on Kalawasan island were comprised of 241 individuals belonging to 21 species. There were 61 individuals (22 species) of trees on Karantina island. The diver- sity index of trees on Kalawasan and Karantina island was 2.55 and 2.72, respectively. The tree evenness index was 0.84 on Kalawasan island and 0.88 on Karantina island. The index of similarity for trees between the two islands was 0.21. Furthermore, the soil character- istics on Kalawasan and Karantina islands showed similarities. In general, soil in Kalawasan and Karantina islands could be catego- rised as marginal soil which was common in East Kalimantan. Con- sidering the rapid loss of tropical forests in the mainland of Kali- mantan indicates that the small islands of Balikpapan Bay play an important role in future biodiversity conservation in East Kalimantan. Keywords: Balikpapan Bay, Dipterocarpaceae, dry land, line tran- sect, soil DOI: 10.15575/biodjati.v5i2.6434 1 Forest Research and Development Institute of Makassar, Jl. Perintis Kemerdekaan Km. 16.5, Makassar, 90243 2,3,4,5,6 Research and Development Ins- titute of Natural Resources Conserva- tion Technology, Jl. Soekarno-Hatta Km. 38, Balikpapan, 76112 e-mail: * 1 t.sayekti@yahoo.com 2 bssitepu@yahoo.com 3 ishakyassir@gmail.com 4 ulfahnazri@gmail.com 5 m.mukhlis.i@gmail.com 6 drhamirmaruf@yahoo.com *Corresponding author