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 5 / 19 PLOS ONE Tropical urban tree selection ′ = − = ∑ H pi log pi i n ( ) ( ) 2 1 (2) Where pi is the proportional abundance of species i. Habitat clustering Habitat clustering used the hierarchical clustering “ward.D” method using R v. 3.6.3 [35] package vegan [36]. Cluster distance was calculated based on the Jaccard index using the rela- tive abundance of tree species in each location. Species selection The selection of tree species for rehabilitation was carried out by scoring and weighing the criteria based on the Analytical Hierarchy Process (AHP) multi-criterion decision-making technique [37]. The publication of AHP articles is growing markedly over time with the great- est increase in the total number of articles concerning the subject area Environmental Science, probably related to the increasing interest in environmental issues in the world. However, AHP in the subject area of Ecology and Ecosystems is relatively new [38]. We applied the AHP technique using the following steps: (1) Problem Identification refers to the identification of the problem (choices) and the criteria that influence these choices, (2) Pairwise Compari- son involves a pairwise comparison of the different criteria of the constructed hierarchy; the relative priorities of the criteria are calculated. (3) Eigenvector Construction and Ranking of Alternatives is the final stage in AHP. Selection was only made on trees identified to the

species level (74% of all individuals). We considered eight criteria for decision making: (i) conservation status, (ii) endemicity, (iii) climax species, (iv) distribution, (v) food potential, (vi) ethnobotanical potential (mainly medicinal or cultural), (vii) animal food, and (viii) tree growth rates. Weighting of criteria used the AHP method by conducting a comparison of paired criteria [39]. Each criterion was scored against the other criteria by assigning a relative dominance value between 1 and 9 (least important to most important) based on expert opin- ion. Five experts in ecology, silviculture, wildlife, botany, and the environment were involved in the analysis (names provided in the Acknowledgments). In addition, these experts were also Table 1. Description of research locations around Ibu Kota Negara Nusantara, East Kalimantan, Indonesia. Location Coordi- nates Elevation (m.a.s.l) Number of plots Total plot area (ha) Date of collection Forest type Arsari Forest S00°54’ E116°34’ 385 22 1.27 2021 Secondary forest Bangkirai Hill S01°02’ E116°52’ 80 48 1.92 2021 Secondary forest Bhirawa S00°52’ E116°28’ 565 42 1.68 2019 Old secondary forest Kenangan S01°03’ E116°44’ 5 39 2.14 2018 & 2021 Secondary forest Parung-Tembinus S00°49’ E116°47’ 180 30 1.32 2021 Karst, old secondary forest Samboja Research Forest S00°59’ E116°57’ 50 16 1.60 2021 Lowland tropical forest, sec- ondary forest, swamp forest Sotek Garden S01°12’ E116°37’ 20 1 10.0 2021 Old secondary forest Sungai Wain Protection Forest S01°09’ E116°50’

15 20 0.80 2019 Lowland tropical forest https://doi.org/10.1371/journal.pone.0320489.t001