ABSTRACT The use of native trees is necessary for land restoration and the sequestration of carbon that is stored in forest biomass production in Indonesia. Meanwhile, the biomass prediction model used for native tropical lowland trees of Indonesia is limited to only specific locations and focuses on aboveground biomass (AGB). This study aimed to select and evaluate potential native tree species for high biomass and to develop the best allometric model for estimating tree biomass production (AGB, belowground/BGB, and total/TB) in lowland ecosystems in Indonesia. Trees were selected using the following five criteria: nativeness, ecosystem type, morphological appearance, multipropagation ability, and economic value. Biomass content was quantified for 102 sample trees (56 trees aged 4 years and 46 trees aged 8 years), using the destructive method. Effective growth biomass and species ecological data indicated five species as potential trees for land restoration in tropical lowlands of Indonesia: Litsea garciae, Terminalia bellirica, Pterospermum javanicum, Anisoptera marginata, and Cananga odorata. The best allometric model of this study is highly recommended for implementation with native trees of tropical lowlands in Indonesia, especially those in early stages (less than 8 years). Meanwhile AGB. AGB . (AGB) AGB, (AGB belowgroundBGB belowground BGB belowground/BGB total/TB totalTB total TB criteria nativeness type appearance ability value 10 56 (5 years, , years) method garciae bellirica javanicum marginata odorata less years. 1 5 (

ABSTRACT The assessment of plant extinction is strongly influenced by the number of populations and the number of localities found for the species target. A larger population and a large number of localities, the results of the assessment will be easier to conclude. However, if the population and location of the plant are not known, even if there is only one location recorded in the herbarium, then there is a challenge in determining the final result of the assessment. This paper will reveal the challenges and the final results of the assessment where only one location is known based on the herbarium records. The species is Beilschmiedia lancifolia Miq. The species was first published in 1852 collected from Mount Ungaran, Indonesia. There have been no additional records of B. lancifolia since its first collection. To update the conservation status of the species, we conducted population assessment in Mount Ungaran using a focused survey method. In spite of the intensive surveys on each side of Mount Ungaran within the species’ known elevation range, we could not find a single individual of B. lancifolia. Based on our findings, we proposed to add the Possibly Extinct (PE) to the present status of B. lancifolia. target conclude However Miq 185 Indonesia B collection method range findings PE (PE 18 1