Possibly Extinct or Data Deficient? A challenge for conservation status assessment based on single locality: Insights from Beilschmiedia lancifolia Miq.

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.