Abstract. Siregar M, Helmanto H, Rakhmawati SU. 2019. Vegetation analysis of tree communities at some forest patches in North Sulawesi, Indonesia. Biodiversitas 20: 643-655. Deforestation has caused a decline in forest area in Indonesia. Now natural forests is left in the conservation areas while those outside conservation areas are narrow and fragmented. This study aims to analyze forest vegetation and conservation status of the species of trees in some forest patches in North Sulawesi. Diversity, structure and type of tree communities at five forest patches, namely in the villages of Bukaka, Garini and Lambak in East Bolaang Mongondow District, and Soyowan and Basaan villages in Southeast Minahasa District, North Sulawesi Province were studied using a point center quarter method. The total number of tree species (dbh ≥ 10 cm) across five patches is 84 species. The highest number of species is in Garini (37 species), followed by Lambak (25 species), Soyowan (19 species), Bukaka (10 species) and Basaan (7 species). The species diversity index also shows the same pattern with such species richness, but the dominance index demonstrates opposite trend. The highest evenness index (E) is found in Bukaka (E = 0.9524), followed by Soyowan (E = 0.9061), Garini (E = 0.7873), Basaan (E = 0.7809) and Lambak (E = 0.7099). The most important tree species based on the Species Important Value (SIV) in Bukaka is Ficus sp. (SIV = 52.17), in Garini is Octomeles sumatrana (SIV = 25.73), in Lambak is Boehmeria cylindrica (SIV = 65.03), both in Basaan and Soyowan is Dracontomelon dao with SIV of 96.87 and 46.46 respectively. The beta diversity analyzed based on species similarity index of Jaccard and Whittaker 's index shows a relatively large change in species composition from one location to another. The family of Moraceae, Malvaceae, Anacardiaceae, Annonaceae and Lauraceae are listed as the widest family with a relatively high population. The highest tree density is found in Bukaka (721 trees ha-1), followed by Lambak (482 trees ha-1), Basaan (439 trees ha-1), Garini (292 trees ha-1) and Soyowan (164 trees ha-1). The highest basal area is also found in Garini (53.59 m2 ha-1), followed by Basaan (51.62 m2 ha-1), Lambak (30.74 m2 ha-1), Soyowan (25.13 m2 ha-1) and Bukaka (20.98 m2 ha-1). The results of Cluster analysis using data of species abundance indicate that the five research locations tend to form two types of tree communities. The first community consists of Garini, Soyowan, Lambak and Bukaka, while the second community is represented only by Basaan.

Indonesian biodiversity including the rich flora is facing various threats, including deforestation, habitat degradation, fire, natural disasters and climate change. Many ex situ conservation strategies have been implemented in response to this problem, including the development of new local botanic gardens in each province throughout Indonesia. The purpose of this paper is to reveal the important role of seed banks in forming part of the botanic gardens’ collections management strategies – they now play an increasingly important role in saving the Indonesian flora from extinction. This study was conducted by undertaking a literature review and analysis of secondary data on the four largest botanic gardens of Indonesia. Currently there are 33 botanic gardens in Indonesia consisting of five national botanic gardens under Lembaga Ilmu Pengetahuan Indonesia (LIPI/Indonesian Institute of Sciences), two botanic gardens under universities and 26 botanic gardens managed by Local Goverments. Among the five national botanic gardens, four manage seed banks: the Seed Bank of the Center for Plant Conservation Botanic Gardens/Bogor Botanic Gardens banks 749 accessions covering 460 species, 305 genera and 114 families; Cibodas Botanic Garden Seed Bank has 61 accessions covering 57 species, 57 genera, 40 families; Purwodadi Botanic Garden Seed Bank has 413 accessions covering 207 species, 134 genera and 46 families; and Eka Karya Bali Botanic Garden Seed Bank maintains 132 accessions covering 89 species, 43 genera and 21 families. The Indonesian Botanic Garden Seed Banks thus hold 1,355 accessions in total, covering less than 1% of total Indonesian plant diversity. In order to increase this coverage, Indonesian seed banking capacity needs to be increased, through the technical development of existing seed banks and the engagement of local botanic gardens throughout Indonesia to establish mini seed banks using the community seed bank approach.