87 Teknologi Indonesia © LIPI Press 2013 DIVERSITY OF PLANTS NATURALLY GROW IN TROPICAL DRY FOREST (T-df) OF BUKIT JIMBARAN BALI Wawan Sujarwo 1,2) and Ida Bagus Ketut Arinasa 1) “Eka Karya” Bali Botanic Garden - Indonesian Institute of Sciences (LIPI) 1) Candikuning, Baturiti, Tabanan, Bali 82191, Indonesia 1) Department of Science, the University Roma Tre, Italy 2) Viale G. Marconi 446 Rome, Italy 2) E-mail: wawan.sujarwo@lipi.go.id; wawan.sujarwo@uniroma3.it Received: 18/06/2013 Revised: 09/10/2013 Accepted: 29/10/2013 ABSTRACT Bukit Jimbaran Bali is considered one of the dry areas on Bali Island. The climate is very dry during the year and has very limited rainfall in the rainy season. The aim of our study is to review the ecology of natural regeneration of T-df, focusing on how the available information can be used to facilitate the recovery of these forests in disturbed areas. Tropical dry forest around Udayana University, which is situated in Bukit Jimbaran Bali, was selected as the investigation area since there was an ongoing CSR (corporate social responsibility) project for establishing urban forest at Udayana University. Sampling plots were established to determine plant diversity of seedlings, saplings, poles, and trees. Research results revealed high diversity of seedlings (40 species) and saplings (35 species) while trees were limited (11 species). We have come to the conclusion that groundcover diversity is high enough (75 species) even though the soil depth is very thin. In addition, there was abundant Acacia auriculiformis which is considered as an invasive species in the area. Keywords: Floristic composition, natural regeneration, tropical dry forest, Bukit Jimbaran Bali. ABSTRAK Bukit Jimbaran Bali merupakan salah satu daerah kering di Pulau Bali. Iklimnya sangat kering sepanjang tahun, dengan curah hujan yang sangat terbatas pada musim penghujan. Tujuan dari penelitian kami adalah untuk mengulas ekologi regenerasi alami hutan tropis kering, dengan berfokus pada bagaimana informasi yang tersedia dapat digunakan untuk memfasilitasi pemulihan hutan di daerah terganggu. Hutan tropis kering di sekitar Uni- versitas Udayana yang terletak di Bukit Jimbaran Bali dipilih sebagai obyek penelitian, mengingat di sana tengah berlangsung proyek CSR (corporate social responsibility) pembangunan hutan kota Universitas Udayana. Sam- pling plot dibuat untuk menentukan keanekaragaman tanaman bibit, pancang, tiang, dan pohon. Hasil penelitian mengungkapkan tingginya keragaman bibit (40 spesies) dan anakan (35 spesies) sementara pohon keragamannya terbatas (11 spesies). Kami menyimpulkan bahwa keragaman tanaman penutup tanah (groundcover) cukup tinggi (75 spesies) meskipun kedalaman tanah (solum) sangat tipis. Selain itu, ditemukan Acacia auriculiformis yang melimpah, yang diduga dapat menjadi spesies invasif di area hutan tropis kering sekitar Universitas Udayana Bukit Jimbaran Bali. Kata kunci: Komposisi flora, regenerasi alami, hutan tropis kering, Bukit Jimbaran Bali. INTRODUCTION There are three reasons to review the ecology of natural regeneration in dry tropical forests (T-df). First, T-df, which originally represented 42% of the tropical vegetation worldwide, is the most threatened tropical terrestrial ecosystem, due to the conversion of these areas into agricultural land. [1,2,3] Thus, scientific knowledge, specifically regarding regeneration pathways, is crucial to the restoration of these forests. Second, there have been insufficient studies of T-df to date. [1,2,3] Third, T-df has particular natural regeneration attributes that need to be clarified. Although these regeneration characteristics can be limiting in Teknologi Indonesia 36 (2) 2013: 87–96 Off print request to: Wawan Sujarwo and Ida Bagus Ketut Arinasa