Tree biodiversity in Bornean lowland forest: What are the key species for forest city development in the new capital city of Indonesia?

PLOS ONE | https://doi.org/10.1371/journal.pone.0320489 April 8, 2025 7 / 19 PLOS ONE Tropical urban tree selection at Parung-Tembinus was slightly higher than in the Samboja Research Forest, the number of species found was much lower. Shannon-Wiener diversity indices for each location ranged from 1.98 to 2.87 (Table 3) with the greatest diversity found in Samboja Research Forest. Clustering by location The eight study locations are divided into two main clusters (Fig 2). Sotek Gardens formed a separate cluster because it is a former community settlement that has not been occupied for a long time, and has developed into an old secondary forest dominated by large-diameter fruit trees. The other seven locations are natural and old secondary forests, and some are burnt areas. The forests in the Bhirawa and Sungai Wain Protection Forests had similar tree species. The Bhirawa sample plot was a production forest area protected by the company as a source of Shorea (and other Dipterocarpaceae) seeds. Sungai Wain was also a protected forest area, so both are relatively safe from disturbances. The forests in Bangkirai Hill and Samboja Research Forest had similar tree species composition because they were relatively close together and the Table 3. Tree species richness and diversity in the eight sample locations within 30 km of Ibu Kota Negara, East Kalimantan, Indonesia. Location Number of trees Density (trees ha-1) Number of species Number of genera Number of families Species diversity (H’) Arsari Forest 619 487 230 128 56 2.31 Bangkirai Hill 962 501 179 108 50 2.50

Bhirawa 435 258 126 84 48 2.12 Kenangan 719 332 128 82 40 1.98 Parung-Tembinus 701 531 137 91 41 2.22 Samboja Research Forest 843 526 212 137 53 2.87 Sotek Garden 1,080 108 83 56 32 2.47 Sungai Wain Protection Forest 386 482 155 95 41 2.63 All locations 5,745 277 571 238 81 2.39 https://doi.org/10.1371/journal.pone.0320489.t003 Fig 2. Habitat cluster dendrogram based on binary data on the presence of tree species in eight forest locations within 30 km of Ibu Kota Negara, East Kalimantan, Indonesia. https://doi.org/10.1371/journal.pone.0320489.g002