Sungbae Joo

Sungbae Joo, Yu-Seong Choi, Sang-Yeon Lee, Dongwoo Yang, Hye-seon Kim, Injung An and Seonah Jeong. J Ecol Environ 2025;49:. https://doi.org/10.5141/jee.25.079

Injung An, Byeori Kim, Sungbae Joo, Kihyun Kim and Taek-Woo Lee. J Ecol Environ 2024;48:. https://doi.org/10.5141/jee.23.060

Eui-Joo Kim, Seung-Hyuk Lee, Sung-Bae Joo and Young-Han You. J Ecol Environ 2023;47:. https://doi.org/10.5141/jee.23.058

Sungbae Joo , Injung An and Sun-Sook Kim. J Ecol Environ 2023;47:. https://doi.org/10.5141/jee.23.049

The Seocheon Tidal Flat is an important staging and wintering site for the Far East Russian population of Swan Goose (Anser cygnoides) in the East Asian–Australasian Flyway. However, rapid environmental changes for tourism in this area can threaten the survival of this vulnerable population by hindering sufficient rest and wintering; therefore, establishing protection strategies based on Swan Goose behavioral characteristics is necessary. Here, we estimated Swan Goose core home ranges and habitat use based on GPS tracking data collected at the Seocheon Tidal Flat in South Korea from 2017–2018. The home range of Swan Geese was estimated to be an area from Yubu Island in the south to Janggu Bay in the north; however, the core home range and habitat use characteristics differed significantly between daytime and nighttime (Day: 59.9 km², Night: 40.3 km², on average, 100% MCP). During the day (08:00–18:00), Swan Geese mostly spent time resting or feeding on tidal flats, especially those around tidal channels or paddy fields near Janggu Bay, whereas they mostly rested on sand dunes near Yubu Island along with the mudflats at Janggu Bay at night. Our results provide practical information on the habitat use of wintering Swan Geese population over time and indicate that Yubu Island is an important resting place. Hence, these results can contribute to evaluating threats to Swan Geese and establishing management and protection strategies for the Seocheon Tidal Flat, a major wintering site for the Far East Russian population of Swan Geese.

To investigate the foraging preferences of the Korean water deer (Hydropotes inermis argyropus) from the Janghang wetlands located in Han River estuary in South Korea, we elucidated their diet compositions using DNA extracted from their fecal samples. Samples were collected from the Janghang wetlands from June 2013 to January 2015. For dietary analysis, we amplified the internal transcribed spacer 2 (ITS2) and the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL) regions, followed by cloning and sequencing. We were able to detect 20 families and 35 genera of plants from 77 fecal samples, showing that water deer in the Janghang wetlands mainly preferred Salicaceae (27.5%), Fabaceae (17.5%), and Poaceae (14.2%). In winter, the relative frequency of woody plant detection (81.3%) was much higher than that in other seasons. Our results suggest that Korean water deer in Janghang wetlands browse or graze depending on the locally-available plants species in their habitat as intermediate feeders. Non-invasive approaches using fecal samples could be applied to study food webs of various species and ecosystems for conservation and management of wildlife.

We have determined the second mitochondrial genome of Epanerchodus koreanus Verhoeff, 1937 collected in limestone cave of Korea. The circular mitochondrial genome of E. koreanus is 15,581 bp long. It includes 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. Its gene order was different from the rest three Polydesmida mitochondrial genomes, resulted from relocation of tRNAs, rRNAs, and ND1. The base composition was AT-biased (75.1%). Phylogenetic trees displayed phylogenetic relationship, which is congruent to previous study, except Sphaerotheriidae sp. clustering with Helminthomorpha.

Propidium monoazide (PMA) is a highly selective dye that penetrates only membrane-compromised, dead microbial cells and inhibits both DNA extraction and amplification. PMA has been widely used for discrimination between living and dead microbial cells; however, the application of PMA in phytoplankton studies has been limited. In this study, we attempted to evaluate its applicability for the discrimination of viable phytoplankton. We tested PMA on seven phytoplankton species, Microcystis aeruginosa, Anabaena sp., Aphanizomenon sp., Synechocystis sp., Cryptomonas ovata, Scenedesmus obliquus, and Nitzschia apiculata as representatives of the major phytoplankton taxa Cyanobacteria (first four species), Chlorophyta, Cryptophyta, and Bacillariophyta, respectively. Our results showed that application of PMA to phytoplankton living in freshwater has the potential to distinguish viable from dead cells as in microbial studies. Particularly, PMA differentiated viable from dead cells in cyanobacterial species rather than in other phytoplankton taxa under our experimental conditions. However, our results also showed that it may be necessary to adjust various conditions affecting PMA treatment efficiency to expand its applicability to other phytoplankton. Although all factors contributing to the effects of PMA could not be evaluated, our study showed the applicability of PMA-based molecular approaches, which can be convenient quantitative methods for distinguishing living from dead phytoplankton in freshwater ecosystems. Setting optimal treatment conditions for other phytoplankton species may increase the efficacy of PMA-based molecular approaches.