Study of the Genetic Diversity in an Effort to Protect the Genus Dacrydium Lamb. In Central Kalimantan, Indonesia

The tropical coniferous genus Dacrydium is widespread in Kalimantan, Indonesia. Four species can still be found in Borneo. Locally known as Alau, this genus thrives in a range of habitats from heath to deep-peat forests especially in Central Kalimantan. This genus is currently threatened by logging, fires and forest conversion forto other uses. The objectives of this study wereas to unravel the genetic diversity of Dacrydium in the study area which is a large unified diverse landscape. Our research was conducted in heath forests located within PT Taiyoung Engreen logging company area in the Gunung Mas District, and PT Dasa Intiga in the Kapuas District and in deep-peat swamp forest located in Sebangau National Park in the Palangkaraya District. The four species that are suspected to exist in Kalimantan, namely Dacrydium beccarii Parl., Dacrydium pectinatum de Laub., Dacrydium elatum (Roxb.)Wall. ex Hook. and Dacrydium xanthandrum Pilg. were met in various abundances. Genetic data were tested by isoenzyme analysis with 20 samples of each species of D. beccarii and D. pectinatum from each site. The results showed that D. beccarii and D. pectinatum have a large number of missing alleles, rare alleles, and individual alleles, which are found in different species in the three research sites, all show their own genetic peculiarities. That makes it necessary to develop a strategy to protect the genus Alau quite locally, especially D. pectinatum is of high concern as it is quite threatened. Genetic diversity values of D. beccarii and D. pectinatum have genetic diversity in population 0.478 and 0,447, interpopulation diversity 0.208 and 0,253, roportion of genetic diversity between populations to total genetic diversity 0.289 and 0,350 with fixation index values (-0.021) and 0,187 (≈0) it has a tendency to random mating. Itis necessary to implement a strategy for saving Dacrydium. This can be implemented from our research site. Actions will include the translocating of individual seedlings between research sites where each has a private allele with different advantages to be planted in all original habitat to increase genetic variation, and establish demonstration plots to safeguard genetic variation and diversity, and additionally carry out genetic enrichment planting, especially for D pectinatum. © 2025 Institute of Physics Publishing. All rights reserved.