Rhizoplane and Rhizosphere Microbiome of Alive and Dead Korean fir (Abies koreana Wilson) in its Native Habitats

Rhizoplane and Rhizosphere Microbiome of Alive and Dead Korean fir (Abies koreana Wilson) in its Native Habitats

Young-Hyun You1, Jong Myong Park2, Tae-Yong Jeong3, Jae-Ho Shin4, Ji Won Hong5*

1Biological Resources Utilization Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea
2Water Quality Research Institute, Waterworks Headquarters Incheon Metropolitan City, Incheon, Republic of Korea
3Department of Environmental Science, College of Natural Sciences, Hankuk University of Foreign Studies, Yongin, Republic of Korea
4Department of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea
5Department of Hydrogen and Renewable Energy, Kyungpook National University, Daegu, Republic of Korea

* Email: jwhong@knu.ac.kr

A rapid decline in the population of Abies koreana has been reported in most of the natural alpine habitats in Korea. Studies on the decline of the Korean fir forests have pointed out that this phenomenon is due to global climate change, even though no clear conclusions have been drawn. Most research has focused on abiotic environmental factors; however, studies on the relationships between A. koreana and soil fungal microbiomes are limited. In this study, the rhizoplane and rhizosphere fungal communities in the alive and dead Korean fir trees from its three major natural habitats, including Mt. Deogyu, Mt. Halla, and Mt. Jiri in Korea were investigated to identify specific soil fungal groups closely associated with A. koreana. In addition, the physiochemical properties of the rhizosphere samples from each site were analyzed. According to soil analysis results, the only limiting nutrient in the growth and survival of A. koreana was available phosphorus. Moreover, based on the beta diversity calculations, the estimated soil fungal diversity in each study site was significantly different from another. According to the heat tree analysis at the genus level, Clavulina, Beauveria, and Tomentella showed a positive correlation with the healthy A. abies, probably by forming ectomycorrhizae with Korean fir. These genera may have played a significant role in the survival and growth of A. abies in its natural habitats. Gyoerffyella showed a negative relationship with A. abies, and this genus may account for the death of the Korean fir seedlings at the early stage of the growth of the plant. Our findings confirmed and suggested that Clavulina, Beauveria, and Tomentella are the major players that could be considered in future A. abies reforestation programs to establish ectomycorrhizal networks between the fungi and Korean fir. The plant pathogens and saprophytes such as Calocera, Dacrymyces, Gyoerffyella, Hydnotrya, Microdochium, Hyaloscypha, Mycosymbioces, and Podospora showing a negative relationship with A. abies should be monitored carefully in order to predict the decline of the Korean fir forests.
Our work presented exploratory research on the specific fungal taxa associated with the status of A. abies and may help to prevent the decline of Korean fir forest.