Conservation of Endangered Tree Species Becomes the Focus of FMIPA UI Doctoral Dissertation

Depok, January 7, 2026 – The Faculty of Mathematics and Natural Sciences, Universitas Indonesia (FMIPA UI), held an open doctoral promotion examination for the Biology Study Program with Aulia Hasan Widjaya as the doctoral candidate. The event took place on Wednesday (January 7) at the Prof. Dr. G.A. Siwabessy Auditorium, FMIPA UI, Depok.

Aulia presented her dissertation entitled “Conservation Strategies for Dehaasia pugerensis Koord. & Valeton (Lauraceae), an Endangered Tree Endemic to East Java, Indonesia,” which highlights efforts to conserve a rare endemic tree species from Puger Forest, Jember, East Java. This species is classified as Critically Endangered by the IUCN and is found only in that region.

Aulia’s research employed an interdisciplinary approach integrating ecology, genetics, genomics, and conservation. She successfully mapped population conditions, community structure, genetic diversity, and tree propagation strategies to support the long-term preservation of this rare species.

“This research underscores the importance of an interdisciplinary approach to protecting D. pugerensis, a relict species adapted to semi-arid karst forests yet highly sensitive to habitat disturbance,” Aulia stated. She also proposed conservation strategies such as habitat protection, control of invasive species, as well as vegetative propagation and tissue culture techniques.

The vegetation study results revealed high biodiversity in the habitat of D. pugerensis, with 90 species from 85 genera and 35 families, comprising more than 1,300 individuals. However, more than half of the species were represented by only one to two individuals, indicating a community structure that is highly vulnerable to local extinction. Molecular analyses using DNA barcoding and chloroplast genomes confirmed the identity of D. pugerensis and highlighted the potential of molecular markers for genetic conservation.

Practical conservation efforts were also carried out through vegetative propagation using shoot cuttings, achieving a highest success rate of 57% and the fastest growth observed within 37 days. This approach demonstrates the potential of ex situ conservation as a complement to in situ protection in the species’ natural habitat.

Aulia emphasized that conserving D. pugerensis is not merely about saving a single species, but also about safeguarding an important evolutionary lineage as well as the ecological functions of tropical forests. “Protecting this tree means preserving the forest ecosystem as a whole,” she stated.

Thanks to this research, Aulia successfully earned her Doctoral degree with a Cum Laude distinction, under the supervision of Dr. Dra. Andi Salamah as promoter, and Dr. Iyan Robiansyah and Tety Maryenti as co-promoters. The open examination was attended by a panel of examiners who provided evaluations and scholarly feedback on her dissertation.